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Summary

Thin-layer chromatography is one of the most efficient analysis methods that have remained very popular for many decades, despite the high rates of modern science development and the relative simplicity of the method discussed. One should note that the frequency of published works is virtually an estimate of the value of the given method by chemists-analysts. The result of the conducted scientometric study permits to make the conclusion on the fact that the TLC method is most often used in its initial kind as a classical ascending elution of plates with a silica gel layer in a saturated chamber in spite of diversity of chambers, ways of elution, and stationary phases [1]. In the present review article, the main directions of the method development, based on the comparison of published works on TLC during 2 time periods with an interval of 10 years (2008 and 2018), are presented.

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Summary

2,4-Dichlorophenoxyacetic acid (2,4-D) is a phenoxy group of herbicide used worldwide. As it is extensively used, it has consequential problems on living beings. 2,4-D is degraded into the chlorinated phenols and catechols, and these phenol compounds are more hazardous than the parent 2,4-D herbicide. In this paper, an attempt is made to detect 2,4-dichlorophenol in 2,4-D poisoning cases from human viscera. Sensitive and selective detection of 2,4-dichlorophenol using high-performance thin-layer chromatography (HPTLC) is possible by coupling it with 4-amminoantipyrene in the presence of potassium ferricyanide. Standard 2,4-dichlorophenol and human visceral extract are allowed to run on an HPTLC plate with hexane, acetone, and ethyl acetate as the mobile phase. Mechanistically, 4-amminoantipyrene reacts with 2,4-dichlorophenol in the presence of potassium ferricyanide to form p-quinoneimide which is brick red in color. This known reaction is, for the first time, applied to detect 2,4-dichlorophenol in 2,4-D poisoning cases from human viscera. The formation of brick red color spot on the HPTLC plate allows the easy and confirmed detection of 2,4-dichlorophenol in 2,4-D poisoning case. This HPTLC method is simple and easy to work in laboratory. The reagents do not react with the parent 2,4-dichorophenoxyacetic acid and other organophosphorus, organochlorine, carbamate, and pyrethroid insecticides, i.e., these reagents are specific. The constituents of the viscera (amino acids, peptides, proteins, etc.) and plant material do not interfere with the reagents. The presence of 2,4-dichlorophenol in the same visceral sample is confirmed by gas chromatography-mass spectrometry (GC-MS). The detection limit of reagents for 2,4-dichlorophenol is approximately 0.5 µg.

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Summary

The aim of this work was to establish qualitative and quantitative methods for studying Guyinye residue extracts and Turkish gall (TG) cream. This study involved qualitative and quantitative analyses of gallic acid and methyl gallate and determined their preliminary antioxidant activity by high-performance thin-layer chromatography (HPTLC) and thin-layer chromatography-1,1-diphenyl-2-trinitrobenzene hydrazine (TLC-DPPH) in Guyinye residue extracts and TG cream. The thin-layer plate was a polyamide film and glacial acetic acid, methanol, ethyl acetate, and formic acid (10:6:2:1, volume ratio) were used as the developing agent. The scanning wavelength was 280 nm. Results showed that the RF values of gallic acid and methyl gallate were 0.57 ± 0.05 and 0.72 ± 0.05, respectively, and their linearity ranges were 0.001–0.005 and 0.00025–0.00125 mg with correlation coefficients of 0.9990 and 0.9994, respectively, which indicated a good linear relationship. The detection limits of gallic acid and methyl gallate were 3 and 75 ng, respectively, and their quantification limits were 10 and 250 ng, respectively. The average recovery was 98.59% and 98.33%, and the relative standard deviation (RSD) was 2.49% and 3.55%, respectively. Gallic acid was more remarkable than methyl gallate in antioxidant activity. Thus, HPTLC combined with TLC-DPPH, which can rapidly and accurately determine gallic acid and methyl gallate in Guyinye residue extracts and TG cream, is a simple, accurate, and rapid qualitative and quantitative method.

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Summary

A simple, specific, and quantitative high-performance thin-layer chromatographic (HPTLC) method has been developed for the quantitative determination of lupeol in 2 marketed formulations, namely, Manasamitra vatakam and Amree plus capsule. Chromatographic development was performed by using a pre-coated silica gel 60 F254 aluminum-backed plate, and the development was carried out using toluene-ethyl acetate (9.48:0.52, V/V) as the optimized mobile phase. The developed TLC plates were derivatized by using anisaldehyde-sulfuric acid reagent. The detection of lupeol was carried out at 600 nm. Box-Behnken design was applied for optimization of the chromatographic conditions, and combinations of factors, such as mobile phase composition (volume of ethyl acetate) (A), chamber saturation time (B), and migration distance (C) likely to affect R F were identified from preliminary trials and further optimized using a response surface design. Among 3 factors, the significant factor found was the volume of ethyl acetate that resulted in higher change in the R F value and can be considered as a critical method parameter. Full factorial design was applied for optimization of extraction efficiency. The factors selected for the optimization process were volume of methanol (A) and duration of extraction (B) with percentage yield of extract as response. The linear ranges were found to be 500–3000 ng per band. The accuracy and precision measured were less than 2% relative standard deviation for lupeol. The sensitivity of the method in terms of the limit of detection (LOD) and the limit of quantification (LOQ) was measured. The proposed method was found to be accurate, precise, reproducible, robust, and specific and can be applicable for the determination of lupeol in the quality-control testing of extract and polyherbal formulations.

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Summary

A simple, sensitive, specific, rapid, and accurate high-performance thin-layer chromatographic (HPTLC) method has been developed and validated for the simultaneous estimation of quercetin (QCT) and resveratrol (RSV). Chromatographic separation was performed over pre-coated TLC plates (60 F254, 20 × 10 cm, 250 µm thickness, Merck, Darmstadt, Germany) through a linear ascending technique. Among the different combinations of the mobile phases used, the best separation was achieved in the toluene-ethyl acetate-formic acid (6:2.5:1.5, V/V) mixture. Detection and quantification were achieved at 286 nm through the spectrodensitometric analysis. Analytical performance of the proposed HPTLC method was validated according to the International Conference for Harmonization (ICH) guidelines with respect to linearity, accuracy, precision, detection, and quantitation limits, robustness, and specificity. The calibration curves were linear in the range of 50–2500 ng per spot for both QCT and RSV, with a correlation coefficient (R 2) of 0.998 and 0.997 for the QCT and RSV, respectively. The detection limits were 122.33 and 370.7 for QCT and RSV, respectively, and the quantitation limits were 27.35 and 82.93 for QCT and RSV, respectively. Additionally, forced degradation studies of QCT and RSV were established. The validated HPTLC method was successfully applied to the simultaneous determination of QCT and RSV in the nanoformulation.

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Oxytropis falcata Bunge, known as the “king of herbs” in Tibetan medicine, is used for treatment of hyperpyrexia, pain, wounds, inflammation, and anthrax. However, it is difficult to efficiently isolate compounds with high purity from O. falcata because of the complexity of traditional Tibetan medicines. In this study, the 80% ethanol elution fraction from extract by AB-8 macroporous resin column chromatography was demonstrated to have anticancer activity on human hepatoma SMMC-7721 cells in vitro. Then, a high-speed counter-current chromatography (HSCCC) method was successfully established for separation of compounds by using hexane–ethyl acetate–methanol–water (10:4:10:10, v/v/v/v) as the solvent system. Five flavonoids (7-hydroxyflavonone [1], 5,7-dihydroxy-4′-methoxy flavonol [2], 5,7-dihydroxyflavanone [3], 2′,4′-dihydroxychalcone [4], and 2′,4′-dihydroxydihydrochalcone [5]) were obtained in one-step separation with purities of 97.7%, 98.1%, 98.3%, 99.0%, and 98.3%, respectively. Finally, anticancer activities against the growth of SMMC-7721 cells of 5 flavonoids were confirmed. The IC50 values of the separated compounds were 213.45 μg/mL, 197.74 μg/mL, 375.16 μg/mL, 17.44 μg/mL, and 136.83 μg/mL in 24 h, respectively. The present study provided a basis for further development and utilization of this medicinal herb as a source of a new potential anticancer agent.

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High-performance thin-layer chromatography (HPLTC)–densitometry methods are described for the analysis of the anti(retro)virals dolutegravir (D), lamivudine (L), and tenofovir disoproxil fumarate (TDF) in a pharmaceutical tablet product. To the best of our knowledge, no previous quantitative planar chromatography method has been reported in the literature for this combination formulation. The method for L was transferred from a thin-layer chromatography (TLC) screening method published in the Global Pharma Health Fund (GPHF) Minilab Manual designed for identification of counterfeit and substandard drug products using a model process published earlier. D and TDF are not included in the list of drugs for which TLC screening methods are published for the Minilab, but HPTLC–densitometry procedures were developed for them using the transfer process guidelines. L was analyzed simultaneously with TDF on Merck Premium Purity silica gel 60 F plates using the mobile phase ethyl acetate–methanol–acetone–concentrated ammonium hydroxide (30:7:3:1) and densitometric scanning at 254 nm. D was analyzed on a second plate by scanning at 366 nm after chromatography with the chloroform–methanol–formic acid (32:8:2) mobile phase. Data for all three drugs are shown to meet the requirements of the model transfer process for calibration curve r values, assay of tablets relative to their label values, peak purity/peak identity tests, and validation by standard addition analysis of samples spiked at 50%, 100%, and 150% of the label value of active ingredients. A TLC screening method for TDF in the combination product was developed and published online with open access.

Open access
Authors: Haiya Wu, Mengrou Lu, Jiamin He, Miaoling Huang, Aote Zheng, Meiling Zhang, Congcong Wen and Jufen Ye

In this study, a precise, rapid, and accurate ultra-performance liquid chromatography–tandem mass spectrometer (UPLC–MS/MS) method for the quantitation of O-demethyl nuciferine in mouse blood was developed, and pharmacokinetics of O-demethyl nuciferine was studied for the first time after sublingual injection and gavage. The study was performed with an UPLC ethylene bridged hybrid (UPLC BEH) (2.1 mm × 50 mm, 1.7 μm) column at 30 °C, using diazepam as the internal standard (IS). The mobile phase consisted of acetonitrile–10 mmol/L ammonium acetate (containing 0.1% formic acid), with a flow rate of 0.4 mL/min for 4 min run time. Multiple reaction monitoring (MRM) modes of m/z 282.1→219.0 for O-demethyl nuciferine and m/z 296.2→265.1 for IS were utilized to conduct quantitative analysis. Protein in mouse blood was directly precipitated with acetonitrile for sample preparation. The linear range was 1–500 ng/mL with r > 0.995, and the lower limits of quantification (LLOQ) was 1 ng/mL. The intra- and inter-day precision of O-demethyl nuciferine in mouse blood were RSD < 14% and RSD < 15%, respectively.r The accuracy ranged from 89.0% to 110.7%, with a recovery higher than 88.9%, while the matrix effect was between 103.1% and 108.7%. We further applied this UPLC–MS/MS method to the pharmacokinetic study on O-demethyl nuciferine after sublingual injection and gavage and determined the bioavailability to be 6.4%.

Open access

The composition and concentration of natural products largely depend on a plant part, development stage, cultivar, and growing conditions. This study evaluated the influence of cultivars and production systems on the composition of natural products (benzoxazinoids) in wheat aerial parts. The determination of benzoxazinoids was performed by combining pressurized liquid extraction, ultra-performance liquid chromatography, and tandem mass spectrometry. Six benzoxazinoids were identified and quantitated in wheat varieties. Significant differences were observed among the examined varieties. The average concentrations of total researched compounds were definitely higher in the organically produced spring wheat cultivars than in the winter ones. The content of these compounds in the same varieties grown under organic and conventional systems showed their higher content under the organic one. The main benzoxazinoids detected in wheat varieties were 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one glucoside (DIMBOA-Glc) and 6-methoxy-2-benzoxazolinone (MBOA). The richest sources of benzoxazinoids were Brawura, Łagwa, and Kandela (52.46, 34.67, and 30.14 μg/g dry weight [DW], respectively).

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RKI-1447 is an effective ROCK1 and ROCK2 inhibitor, having anti-invasion and anti-tumor activity. In this study, we used ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) to detect RKI-1447 in rat plasma and investigated its pharmacokinetics in rats. Diazepam was utilized as an internal standard, and an acetonitrile precipitation method was used to process the plasma samples. Chromatographic separation was achieved using a UPLC ethylene bridged hybrid (BEH) column (2.1 mm × 50 mm, 1.7 μm) with a gradient acetonitrile–water mobile phase (containing 0.1% formic acid). Flow rate was set at 0.4 mL/min. Electrospray ionization (ESI)–tandem mass spectrometry in multiple reaction monitoring (MRM) mode with positive ionization was applied: m/z 327.1 → 204.0 and 285.1 → 193.3 for RKI-1447 and internal standard, respectively. The results indicated that within the range of 10–2000 ng/mL, the linearity of RKI-1447 in rat plasma was acceptable (r > 0.995), and the lowest limit of quantification (LLOQ) was 10 ng/mL. Intra-day precision RSD of RKI-1447 in rat plasma was lower than 8%, and inter-day precision RSD was lower than 11%. Accuracy range was between 91.6% and 107.1%, and the matrix effect was between 85.1% and 87.0%. The analysis method was sensitive and fast with suitable selectivity, and was successfully applied in the pharmacokinetics of RKI-1447 in rats. The bioavailability of the RKI-1447 was 7.3%.

Open access

Irinotecan (IRT) is an antineoplastic agent widely used in the treatment of various cancers primarily in colorectal cancer. A new, simple and sensitive high-performance liquid chromatography (HPLC) method coupled with fluorescence detector was developed and validated to quantify IRT and its active metabolite SN38 in the plasma of non-obese diabetic/severe combined immune-deficient mice (NOD/SCID) mice bearing colon tumor. The plasma samples were extracted by precipitation method using acetonitrile with 0.1% formic acid. The chromatographic separation was achieved using mobile phase consisted of water and acetonitrile (57:43 v/v) pH 3 at the flow rate of 0.8 mL/min in C18 column (internal diameter, 250 × 4.6 mm; pore size, 5 μm). The method was validated according to the bioanalytical guidelines defined by Food and Drug Administration (FDA) and European Medicine Agency (EMA). A regression (R ) value of 0.999 and 0.997 for IRT and SN38 suggested the good linearity in the range of 0.1–10 μg/mL and 5–500 ng/mL, respectively. The calculated lower limit of quantification (LLOQ) and limit of detection (LOD) for IRT were 0.1 and 0.065 μg/mL, respectively. However, for SN38, LLOQ and LOD were 5 and 2 ng/mL, respectively. The intra-day and inter-day variations (coefficient of variance; % CV) observed during the validation were found to be within the set limit of 15%. Both accuracy and percentage recovery analyzed and calculated from the quality control samples were in the between the defined range of 85–115%. Plasma samples were found to be stable when stored at room temperature for 2 h, after 2 freeze–thaw cycles and at −80 °C for 2 months. The developed method was successfully applied to study the plasma elimination profile of IRT in NOD/SCID mice with tumor. The results from plasma concentration time profile and pharmacokinetic parameter analyzed suggested the rapid elimination of IRT and SN38 from the plasma of NOD/SCID mice.

Open access

High-performance liquid chromatography (HPLC) is a widely used technique for the simultaneous detection and quantification of different drugs. The purpose of the current study was to develop a simple and cost-effective reversed-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous determination of tizanidine (TZN) HCl and meloxicam (MLX) in rabbit's plasma. Assay of TZN and MLX was performed after extraction of drug from plasma by liquid–liquid extraction technique using methanol and diethyl ether as protein precipitants. Isocratic elution was performed in a Kromasil® C18 column (dimension, 250 × 4.60 mm; particle size, 5 μm) with mobile phase consisting of methanol–water (8:2). Orthophosphoric acid was used to adjust the pH of the mobile phase 3.0, and detection was done at 228 nm. Flow rate was 0.8 mL/min with ambient temperature and average operating pressure of 1400 psig. Retention time of TZN was 2.612 min and that of MLX was 6.960 min with a resolution of 3.18. Both drugs showed satisfactory linearity in the range of 10 to 50 ng/mL with correlation coefficients (R 2) of 0.9989 and 0.9972 for TZN and MLX, respectively. The developed method was validated successfully for linearity, system suitability, intra-day and inter-day accuracy, and precision, robustness, and specificity following International Conference on Harmonization (ICH) guidelines. Conclusively, a precise, stable, reproducible, economical, and suitable method for estimation of pharmacokinetic evaluation was developed and validated.

Open access

Diabetes mellitus and concurrent hypertension disorder are dreadful all over the world and are often managed by some drugs, such as metformin hydrochloride (MFH), enalapril maleate (ENM), and captopril (CAP). In this work, a reliable and fast quantitative analysis of these three components in tablets was carried out by Tchebichef image moment method and multivariate curve resolution with alternating least squares on three-dimensional (3D) spectra obtained by high-performance liquid chromatography coupled with photodiode array detection (HPLC-PAD). 3D spectra were obtained within only 2 min, and linear quantitative models were established by stepwise regression based on the calculated image moments. Among these two methods, Tchebichef image moment method showed outcome distinction. The correlation coefficients of cross-validation (R Loo-cv) are more than 0.988, while their recoveries are 100.1 ± 1.7% (MFH), 95.4 ± 5.4% (ENM), and 105.3 ± 5.7% (CAP), respectively. The intra- and inter-day precisions (RSD) are less than 5.42%. The proposed methods were also applied to the analysis of real tablets. This study reveals the effectiveness and convenience of the proposed image-moment method that may be a potential technology for the quality control and investigation of drugs in routine analysis.

Open access
Authors: Young Sang Kwon, Sung-Gil Choi, Seung-Min Lee, Jong-Hwan Kim and Jong-Su Seo

The applicability of gas chromatography–triple quadrupole mass spectrometry (GC–MS/MS) for determination of dioxins in soil was investigated. The analytical method was validated based on US Environmental Protection Agency (EPA) Method 1613 and European Union (EU) Regulation No. 709/2014 for selectivity, linearity of sensitivity, and instrumental limits of quantification (iLOQs). Method development commenced with determination of retention times for 17 native polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and selection of characteristic ions from GC–MS/MS spectra. The linearity was measured using 1613 standard solutions (CS1–CS5) containing 0.5 to 200 ng/mL tetrachlorodibenzo-p-dioxin/furan (TCDD/F) congeners, 2.5 to 1000 ng/mL pentachlorodibenzo-p-dioxin/furan (PeCDD/F) to heptachlorodibenzo-p-dioxin/furan (HpCDD/F) congeners, and 20 to 2000 ng/mL octachlorodibenzo-p-dioxin/furan (OCDD/F) congeners. The correlation coefficient (R 2) values ranged between 0.9990 and 0.9999, and the iLOQ values ranged from 0.052 to 0.350 pg/μL for TCDD/F congeners, with a relative standard deviation of 2.7–9.6%. The entire analytical method was verified by analysis of certified reference materials (BCR-529 and BCR-530), and the recoveries were 71.79–103.87% and 81.50–103.12%, respectively. Thus, the GC–MS/MS system provides an alternative to GC–high-resolution MS for the simultaneous determination of TCDD/F congeners in soil.

Open access

A rapid, simple, and sensitive method has been developed for the analysis of pyrethroid herbicides in fruits by using headspace in-tube microextraction (HS-ITME) coupled with reverse-flow micellar electrokinetic capillary chromatography (RF-MECC). In the newly developed method, by placing a capillary filled with background electrolyte (BGE) of RF-MECC in the HS above the sample solution, the pyrethroid herbicides were extracted into the acceptor phase in the capillary. After extraction, electrophoresis of the extracts in the capillary was carried out. The influence of some essential BGE components such as sodium dodecyl sulfate (SDS) and organic modifiers concentrations was investigated. Extraction parameters were also systematically investigated, including the extraction temperature, extraction time, salt concentration, and volume of the sample solution. Under the optimized conditions, enrichment factors for three pyrethroids were 309, 133, and 288, respectively. The proposed method provided a good linearity, low limits of detection (below 1.00 ng/mL), and good repeatability of the extractions (relative standard deviations [RSDs] below 7.83%, n = 6). The fruit samples were analyzed by the proposed method, and the obtained results indicated that the proposed method provides acceptable recoveries and precisions.

Open access
Authors: Shaoshi Wen, Zixin Zhang, Xiaopeng Chen, Jinchang Liu, Haiyang Yu, Lifeng Han, Lijun Jin, Yi Zhang and Tao Wang

Uric acid (UA) is the final product of purine metabolism in humans. Elevated serum UA levels lead to the development of hyperuricemia, gout, kidney diseases, and metabolic syndrome. Accurate determination of UA plays a critical role in clinical diagnosis and laboratory investigation. An ultra-performance liquid chromatography (UPLC) with ultraviolet detection method has been developed and validated for UA analysis. Separation was achieved by a Waters ethylene bridged hybrid (BEH) Amide column (50 mm × 2.1 mm i.d., 1.7 μm) with acetonitrile and 0.1% acetic acid in deionized water in the proportion of 90 to 10 (v/v) as the mobile phase. The limit of detection and limit of quantification were 0.09 and 0.18 μmol/L, respectively. The method was validated by evaluating recovery (98.37–104.20%), accuracy (0.47–0.90%), and precision (1.24–1.81% for intra-batch and 1.76–3.98% for inter-batch). This method was then applied to UA determination in rat serum of hyperuricemia model. The results from UPLC, high-performance liquid chromatography (HPLC), and uric acid kits (phosphor-tungstic acid-based kit and uricase-based kit) were compared. The UPLC results were in very good agreement with HPLC. The developed method could be employed as a useful tool for the determination of UA in biofluids.

Open access
Authors: Shanjiang Chen, Miaoling Huang, Zheng Yu, Jiamin He, Binge Huang, Xianqin Wang, Jianshe Ma and Congcong Wen

8-O-Acetylharpagide is the main active component of the herb Ajuga decumbens, which possesses anti-tumor, anti-virus, and anti-inflammation properties. In this study, ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was used to measure the concentration of 8-O-acetylharpagide in mouse blood, with subsequent investigation of the pharmacokinetics of the drug after intravenous or oral administration. Shanzhiside methyl ester was used as an internal standard, and the acetonitrile precipitation method was used to process the blood samples. Chromatographic separation was achieved using an ultra-performance liquid chromatography ethylene-bridged hybrid (UPLC BEH) column (2.1 mm × 50 mm, 1.7 μm) with a gradient methanol–water mobile phase (containing 0.1% formic acid). The flow rate was 0.4 mL/min, and the elution time was 5.0 min. 8-O-Acetylharpagide was quantitatively measured using electrospray ionization (ESI) tandem mass spectrometry in multiple reaction monitoring (MRM) mode with positive ionization. The result indicated that, within the range of 5–500 ng/mL, the linearity of 8-O-acetylharpagide in mouse blood was satisfactory (r > 0.995), and the lower limit of quantification (LLOQ) was 5 ng/mL. Intra-day precision relative standard deviation (RSD) of 8-O-acetylharpagide in blood was lower than 9%, and the inter-day precision RSD was lower than 13%. The accuracy range was between 94.3% and 107.1%, average recovery was higher than 91.3%, and the matrix effect was between 100.8% and 110.8%. This analytical method was sensitive and fast with good selectivity and was successfully applied to perform pharmacokinetic studies of 8-O-acetylharpagide in mice. The bioavailability of 8-O-acetylharpagide was 10.8%, and the analysis of the primary pharmacokinetic parameters after oral and intravenous administration indicated that 8-O-acetylharpagide had a significant first pass effect after oral administration.

Open access

Objectives

A simple, rapid, selective, and sensitive high-performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed for the simultaneous determination of levocetirizine dihydrochloride and montelukast sodium in human plasma using fexofenadine hydrochloride as an internal standard.

Method

Liquid–liquid extraction of both drugs and internal standard from plasma into ethyl acetate was used for sample preparation and analysis. Separation of both drugs and internal standard was achieved on an Inertsil ODS-3 (4.6 mm × 50 cm, dp 5 μm, particle size) column using an isocratic mobile phase of acetonitrile and 10 mM ammonium formate adjusted to pH 8 with 50 μL ammonium hydroxide in composition of 73:27 (v/v) at a flow rate of 0.7 mL/min. The LC–MS/MS was operated under the multiple reaction monitoring mode (MRM) using an electrospray ionization technique. Mass parameters were optimized to monitor transitions at m/z [M + H]+ 389.0 → 200.8 for levocetirizine dihydrochloride, m/z [M + H]+ 586.2 → 422.2 for montelukast sodium, and m/z [M + H]+ 502.2 → 466.0 for fexofenadine hydrochloride.

Results

The method was found to be linear in the range of 1–500 ng/mL for both drugs. The intra-day and inter-day precision were in the range of 0.96–1.92% and 1.03–1.55%, respectively. Matrix effect was acceptable with %RSD < 15.

Conclusion

The proposed method was validated and successfully applied for a pharmacokinetic study of both drugs in human plasma after oral administration of their pharmaceutical preparation.

Open access

SimiaoYong'an decoction, a traditional Chinese medicine formula consisting of four herbs, has been widely used for the treatment of gangrene disease. However, its clinical application is restricted due to the lack of an effective quality control method that covers the main active compounds in the formula. In this study, a high-performance liquid chromatography with diode-array detection (HPLC–DAD) method was established for the simultaneous determination of 13 active compounds including harpagide, neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, ferulic acid, isochlorogenic acid B, isochlorogenic acid A, isochlorogenic acid C, angoroside C, harpagoside, cinnamic acid, glycyrrhizic acid, and ligustilide. Separation of these compounds was achieved using a Kromasil 100-5-C18 column with a gradient elution program consisting of acetonitrile and 0.4% phosphoric acid solution. The specificity, linearity, precision, repeatability, and accuracy tests were implemented to validate the method. The validated method was successfully applied for determination of 13 components from several finished batches of SimiaoYong'an decoction. The results demonstrated that the established method was accurate, reliable, and could be used as a suitable quality control method for the quantification of SimiaoYong'an decoction.

Open access

A simple, rapid, and sensitive liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed and validated for the simultaneous quantitation of PA-824 and moxifloxacin in rat plasma using carbamazepine as an internal standard (IS). The sample preparation involved a one-step protein precipitation method with methanol. The separation was performed on Inertsil® ODS3 C18 column (150 mm × 4.6 mm, 5 μm) and maintained at 30 °C. The mobile phase consisted of 0.1% formic acid in acetonitrile–water (90:10 v/v) with fast isocratic elution at a flow rate of 0.6 mL/min and a run time of 10 min. A mass spectrometer was run in the positive ion electrospray ionization (ESI) mode using multiple reaction monitoring (MRM) to monitor the mass transitions. The MRM transitions were chosen to be m/z 360.1 → m/z 175.0 for PA-824, m/z 402.0 → m/z 383.9 for moxifloxacin, and m/z 237.1 → m/z 194.0 for IS. The method was fully validated in terms of selectivity, linearity, accuracy, precision, matrix effect, recovery, and stability, respectively. The method was successfully applied to drug–drug interaction (DDI) study of PA-824 and moxifloxacin in rats. The results show that the main pharmacokinetic parameters of PA-824, namely, T max, t 1/2, and AUC(0–t), increased more in the PA-824 and moxifloxacin group than in the PA-824 group. However, there were little changes in the main pharmacokinetic parameters of moxifloxacin from single and combined groups.

Open access
Authors: Azazahemad A. Kureshi, Chirag Dholakiya, Tabaruk Hussain, Amit Mirgal, Siddhesh P. Salvi, Pritam C. Barua, Madhumita Talukdar, C. Beena, Ashish Kar, T. John Zachariah, Premlata Kumari, Tushar Dhanani, Raghuraj Singh and Satyanshu Kumar

Xanthones are well recognized as chemotaxonomic markers for the plants belonging to the genus Garcinia. Xanthones have many interesting pharmacological properties. Efficient extraction and rapid liquid chromatography methods are essentially required for qualitative and quantitative determination of xanthones in their natural sources. In the present investigation, fruit rinds extracts of 8 Garcinia species from India, were prepared with solvents of varying polarity. Identification and quantification of 3 xanthones, namely, α-mangostin, β-mangostin, and γ-mangostin in these extracts were carried out using a rapid and validated ultra-high-performance liquid chromatography–photodiode array detection (UHPLC–PDA) method at 254 nm. γ-Mangostin (3.97 ± 0.05 min) was first eluted, and it was followed by α-mangostin (4.68 ± 0.03 min) and β-mangostin (5.60 ± 0.04 min). The calibration curve for α-mangostin, β-mangostin, and γ- mangostin was linear in the concentration range 0.781–100 μg/mL. α-Mangostin was quantified in all 4 extracts of Garcinia mangostana. Its content (%) in hexane, chloroform, ethyl acetate, and methanol extracts of G. mangostana was 10.36 ± 0.10, 4.88 ± 0.01, 3.98 ± 0.004, and 0.044 ± 0.002, respectively. However, the content of α-mangostin was below the limit of detection or limit of quantification in the extracts of other Garcinia species. Similarly, β-mangostin was quantified only in hexane (1.17 ± 0.01%), chloroform (0.39 ± 0.07%), and ethyl acetate (0.28 ± 0.03%) extracts of G. mangostana. γ-Mangostin was quantified in all 4 extracts of G. mangostana. Its content (%) in hexane, chloroform, ethyl acetate, and methanol extracts of G. mangostana was 0.84 ± 0.01, 1.04 ± 0.01, 0.63 ± 0.04, and 0.15 ± 0.01, respectively. γ-Mangostin was also quantified in hexane (0.09 ± 0.01), chloroform (0.05 ± 0.01), and ethyl acetate (0.03 ± 0.01) extracts of G. cowa, ethyl acetate extract of G. cambogia (0.02 ± 0.01), G. indica (0.03 ± 0.01), and G. loniceroides (0.07 ± 0.01). Similarly, γ-mangostin was quantified in 3 extracts of G. morella, namely, hexane (0.03 ± 0.01), chloroform (0.04 ± 0.01), and methanol (0.03 ± 0.01). In the case of G. xanthochymus, γ-mangostin was quantified in chloroform (0.03 ± 0.001) extract only. α-Mangostin and β-mangostin were not detected in any of 4 extracts of G. pedunculata.

Open access

Simple and economical methods for chiral separations are always needed in synthesis and drug development and as biomarkers, besides many other useful applications. Cyclodextrins (CDs) are chiral host molecules and have been used to separate a number of chiral analytes. In this study, we have successfully prepared electrospun films of β-CD incorporated into polyvinyl alcohol (PVA) through glutaraldehyde (GA) crosslinking. These films of β-CD-PVA-GA electrospun fibers are characterized by Fourier transform infrared (FTIR) and scanning electron microscopy (SEM), which were subsequently used for thin-layer chromatography (TLC)-based enantiomeric separation of histidine and serine pairs. Amino acids were detected by spraying the chromatograms with the ninhydrin solution. Among various solvent systems employed, it was found that the separation of serine enantiomers with a resolution of 1.6 was possible with the mobile phase ethanol–butanol–ethyl acetate–water–acetone (4:5:5:0.5:1.5, v/v), and histidine enantiomers with a resolution of 1.4 were possible with the mobile phase ethanol–butanol–ethyl acetate–water–acetone (4:5:4.5:0.5:1.5, v/v). This proves that the prepared stationary phase is efficient in enatioresolution of selected amino acid pairs and can be further examined for physiological samples.

Open access

A hollow-fiber liquid-phase microextraction (HF-LPME), followed by high-performance liquid chromatography–ultraviolet (HPLC–UV) method for the trace determination of carvedilol (β-blocker) in biological fluids, has been described. The separation was achieved using Inertsil ODS-3 C18 (250 mm × 4.6 mm, 3 μm) column with a mobile phase composition of 10 mM phosphate buffer (pH 4.0)–acetonitrile (50:50, v/v) at a flow rate of 1.0 mL/min, under isocratic elution. Several parameters (i.e., type of organic solvent, donor phase pH, concentration of acceptor phase (AP), stirring rate, extraction time, and salt addition) that affect the extraction efficiency were investigated. The optimum HF-LPME conditions were as follows: dihexyl ether as an organic solvent; donor phase pH, 10.7; 0.1 M HCl (AP); 1100-rpm stirring rate; 60-min extraction time; and no salt addition. These parameters have been confirmed using design of experiments. Under these conditions, an enrichment factor of 273-fold was achieved. Good linearity and correlation coefficient were obtained over the range 5–1000 ng/mL (r 2 = 0.9994). Limits of detection and quantitation were 1.2 and 3.7 ng/mL, respectively. The relative standard deviation at 3 different concentration levels (5, 500, and 1000 ng/mL) were less than 13.2%. Recoveries for spiked urine and plasma were in the range 80.7–114%. The proposed method is simple, sensitive, and suitable for the determination of carvedilol in biological fluids.

Open access

Summary

A sensitive and simple high-performance thin-layer chromatographic method is developed and validated according to the International Conference on Harmonisation (ICH) guidelines. The procedure was applied for the estimation of orlistat in different pharmaceutical preparations. In the proposed method, thin-layer chromatography aluminum sheets pre-coated with silica gel were employed as the stationary phase. A number of solvent mixtures were used as the mobile phase for trials to obtain compact bands of orlistat. The solvent mixture consisting of chloroform and methanol (98:2) was found to be the best. The data obtained from the calibration curves of standard orlistat showed a good linear relationship over the concentration range of 1000–3800 ng per band with respect to the area. Scanning was performed at λ = 200 nm, where the correlation coefficient (R 2) was 0.970, and the linear regression equation was found to be: y = 4.1419x − 4181.1. After revealing of the spots by anisaldehyde–conc. sulfuric acid, compact violet bands were obtained and, accordingly, scanning was performed at λ = 600 nm, where a good linear relationship over the concentration range of 600–4000 ng per band with respect to the area was obtained. The correlation coefficient (R 2) was 0.991 with a linear regression equation: y = 4.025x − 1159.3. The method was evaluated regarding accuracy, precision, limits of detection and quantification, and robustness. Revealing of the spots by anisaldehyde–conc. sulfuric acid improved the sensitivity of the method and increased the range within which a linear relationship between concentration and response occurs.

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Authors: Pankaj B. Miniyar, Asha B. Thomas, Resham D. Kulkarni, Supriya A. Kadam, Parminder P. Chouhan and Sohan S. Chitlange

Summary

Genetic mutations, chromosomal breaks, and chromosomal rearrangements, which are induced due to organic impurities, are considered as potential genotoxic impurities. The European Medicines Agency (EMA) and the United States Food and Drug Administration (US FDA) have set a threshold of toxicological concern (TTC) of 1.5 µg per person per day for each impurity. A sensitive and simple high-performance thin-layer chromatography (HPTLC) method has been developed and validated for determination of the potential genotoxic impurity, namely, 2-chloroaniline, at trace levels in quetiapine fumarate. The method was found to be specific and selective for the application. The limit of detection (LOD) and limit of quantification (LOQ) for quetiapine fumarate were found to be 1.27 and 3.87 ng per band. The LOD and LOQ values for 2-chloroaniline were found 0.018 and 0.054 ng per band, respectively. The calibration curve for 2-chloroaniline was linear over a concentration range from 2.5 to 12.5 ng. The method was found to be specific, precise, linear, and accurate and can be employed for monitoring and estimation of levels of 2-chloroaniline in quetiapine fumarate.

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Summary Two validated, simple, and precise chromatographic methods were described for the determination of vildagliptin (VIL) and metformin (MET) in the presence of metformin toxic impurity, melamine (MEL). Method 1 is thin-layer chromatography (TLC)–densitometric method, at which methanol–chloroform–formic acid (7:3:0.3, by volume) was used as the developing system, and separation was carried out on Merck TLC silica gel 60 F254 aluminum sheets. The developed plates were air-dried and scanned at 215 nm. Linearity was constructed in the range of 0.2–2.6, 0.4–4.5, and 0.05–1.4 µg per band of VIL, MET, and MEL, respectively. Method 2 is reversed-phase ultra-performance liquid chromatography (RP-UPLC), where the separation was performed on a C18 column using methanol-acetonitrile–0.01 m sodium dihydrogen phosphate solution containing 50% 0.01 m sodium lauryl sulfate, pH = 5 with H3PO4 as the mobile phase at a flow rate of 1 mL min−1 at 205 nm. The calibration curves showed good linear relationships in the concentration ranges of 1–50, 2–70, and 0.5–30 µg mL−1 of VIL, MET, and MEL, respectively. The developed methods were applied to Galvus Met® tablets, and no interference from excipients was observed. The methods were validated as per the International Conference on Harmonisation (ICH) guidelines, and they compared favorably with the reported one.
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Author: Bernd Spangenberg
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Summary A validated reversed-phase thin-layer chromatography (RP-TLC)–densitometry method was developed and optimized for the determination of trimetazidine dihydrochloride (TMZ) and its potential impurities listed in the British Pharmacopoeia, namely, piperazinecarboxaldehyde (Y-145), trimethoxybenzyl alcohol (Y-235), and trimethoxybenzaldehyde (Y-234). Chromatographic separation was performed on aluminum plates pre-coated with silica gel 60 RP-18F using a mixture of acetonitrile–methanol–0.1% aqueous ortho-phosphoric acid pH 6.2 (4.5:4.5:1, V/V) as the developing system. Different factors affecting resolution were studied and optimized. Successful resolution was observed with significant difference in the RF values of 0.21 ± 0.02, 0.35 ± 0.02, 0.5 ± 0.02, and 0.85± 0.02 for TMZ and its impurities, respectively. Densitometric measurement was done at 215 nm over the range of 0.05–10, 0.05–1.1, 0.05–1.2, and 0.04–1.0 µg per spot with lower limits of detection (LOD) and quantification (LOQ) of 20 and 50 ng per spot for TMZ, Y-145, and Y-235, respectively, and 15 and 40 ng per spot for Y-234 impurity. Good accuracy was obtained with mean percentage recoveries of 99.55 ± 1.06, 100.50 ± 1.16, 100.07 ± 1.24, and 99.41 ± 1.11 for TMZ and its impurities, respectively. The developed method was used to investigate the impurity profile of TMZ in drug substance and different products and it was validated as per the International Conference on Harmonisation (ICH) guidelines.
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Summary A sensitive and precise high-performance thin-layer chromatographic (HPTLC) method has been developed for the simultaneous estimation of mirabegron and solifenacin succinate in combination. The method employed HPTLC aluminum plates pre-coated with silica gel 60 F254 as the stationary phase and methanol–ethyl acetate–triethylamine (8:2:0.1, V/V) as the mobile phase. The RF value was observed to be 0.76 and 0.56 for mirabegron and solifenacin succinate, respectively. Densitometric analysis was carried out in the absorbance mode at 222 nm. The method was linear in the range of 2–5.5 µg per band for mirabegron and 0.4–1.1 µg per band for solifenacin succinate. The method was validated as per the International Conference on Harmonisation (ICH) guideline and applied successfully for the estimation of both drugs in a physical mixture.
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Summary A novel spot test and a novel chromogenic reagent are reported for thin-layer chromatographic detection and identification of the popular but highly toxic herbicide paraquat. Alkaline phenylhydrazine instantly reduces paraquat to an intense purple radical cation. The reaction is sensitive and highly specific to viologens, i.e., paraquat and diquat herbicide. Surprisingly, 2,4-dinitrophenylhydrazine does not have reaction in this color test. Reaction of the two drugs containing related functional groups is also studied to check whether these drugs also react similarly. Based on this novel color reaction, a simple, ultra-low-cost filter-paper-based sensor is also designed for direct field testing of suspicious forensic samples like vomits and bottle of poison, which are usually found at a crime scene. The possible applications of the reported reaction in the field of organic qualitative analysis, clinical chemistry, and forensic medicine are also discussed.
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Summary

The chromatographic behavior of 24 inorganic anions has been studied on tri-n-butyl amine (TBA) impregnated silica gel-G layers using single solvents, two-component non-aqueous mixtures, and aqueous solutions of organic acids as mobile phases. The mechanism of migration is explained in terms of adsorption, precipitation, solubility of sodium or potassium salts of the anions, and the polarity of the mobile phase used. The effect of pk1 of the complexing acids and that of dielectric constant (∈) of non-aqueous solvents used as mobile phases on the R F values of anions are discussed. Twenty-percent TBA impregnated silica gel-G layers are found quite effective in the separation of anions. The effect of the addition of DMF to other organic solvents on the R F values is also discussed. A number of useful binary and ternary separations are achieved, e.g., the separation of coexisting I, IO3−, and IO4− and of Fe(CN)64 and Fe(CN)63 from their mixtures. The R F values of the anions are found to be in accordance with their lyotropic numbers.

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Summary

A thin-layer chromatographic (TLC)–densitometric method for the separation and simultaneous determination of 3 5-HT3 receptor antagonists, namely, tropisetron hydrochloride (TRP), granisetron hydrochloride (GRN), and ondansetron hydrochloride dihydrate (OND) was developed. Densitometric measurements were done at 285 nm for TRP and 305 nm for both OND and GRN using the reflectance–absorbance mode. Separation was carried out on silica gel TLC plates using chloroform–methanol–ammonia (10 m) (8:2:0.1, V/V) as the mobile phase. The three drugs have been separated with R F values of 0.23 ± 0.01, 0.63 ± 0.01, and 0.76 ± 0.01 for TRP, GRN, and OND, respectively. The limits of detection and quantification for linear regression analysis of the studied drugs ranged from 2.79 to 12.05 and from 8.45 to 36.50 ng per band, respectively, while for polynomial regression, the limits of detection and quantification for the studied drugs ranged from 3.40 to 15.51 and from 10.31 to 46.99 ng per band, respectively. The developed method was applied for determination of the studied drugs in pharmaceuticals and human plasma with good precision and accuracy. Stability-indicating thin-layer chromatographic method for the determination of OND in the presence of its degradation products under different conditions and subsequent kinetic study had been successfully applied.

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Summary The present research work highlights the benefits of analytical quality-by-design (QbD) approach to optimize high-performance thin-layer chromatography (HPTLC) method for the simultaneous quantification of empagliflozin and metformin in fixed dose combination. With a QbD model, the present study endeavors to establish the method operable design region (MODR) for optimization of the HPTLC method assay by means of design of experiments (DOE) and response surface methodology, in order to achieve a good separation and quantification of all analyzed compounds along with an acceptable analysis time. A deep understanding of the quality target product profile (QTPP) and of the analytical target profile (ATP), followed by a risk assessment for variables that affect the efficiency of the method, led to the development of a precise, accurate, and cost-effective method. The method was established on pre-coated silica gel 60 F254 aluminum plates using ammonium acetate (2%)–methanol–acetonitrile–ethyl acetate (3:1:4.5:1.5) as the mobile phase at a detection wavelength of 228 nm. Numerical optimization was performed using the Derringer's desirability approach and ANOVA to develop optimized chromatography. The RF values were 0.49 and 0.81 for metformin and empagliflozin, respectively. The limits of detection for empagliflozin and metformin were found to be 3.49 ng per band and 109.7 ng per band, respectively, while the limits of quantification for empagliflozin and metformin were found to be 10.58 ng per band and 330.54 ng per band, respectively. The intra- and inter-day precisions were less than 2%, with accuracies between 98 and 102% of the true values. The method was successfully applied to quantify empagliflozin and metformin in fixed dose combinations.
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Summary

A simple, selective, sensitive, and precise high-performance thin-layer chromatographic technique was followed to determine the diversity within accessions of Solanum nigrum. Fruit, stem, leaf, and root samples extracted in methanol were used to quantify withanolide A and withaferin A. Significant difference has been detected among the different plant parts. The maximum amount of withaferin A has been found to be present in the leaf sample (71.65 ± 2.86 mg g−1 DW), followed by the stem sample, while the least amount of withaferin A has been detected in the mature fruit sample (5.97 ± 1.91 mg g−1 DW).

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Authors: Amir Ali, Umar Farooq, Mahmood Ahmed, Muhammad Makshoof Athar, M. Salman, Saira Arif, Kashif Nadeem and Hassan Naz

The present work described a simple, rapid, sensitive, accurate, and precise method for simultaneous determination of chlorpheniramine maleate (CHRM) and prednisolone acetate (PRED) in injection samples by high-performance liquid chromatography (HPLC) coupled with UV–Vis detection. Chromatographic separation was accomplished, employing isocratic mode and a mobile phase comprised of acetonitrile and a phosphate buffer (50:50, v/v, 30 °C), adjusted to pH 3.0. The flow rate used was 1.0 mL/min on a Thermo Hypersil ODS C18 column (5 μm, 4.6 × 250 mm), and the injection volume of sample was 20 μL. Analysis of CHRM and PRED was performed at a wavelength of 254 nm. The runtime for analysis was 12.5 min, and the retention times of CHRM and PRED were found to be 2.81 and 5.07 min, respectively. The calibration graph showed linearity over the concentration range 10–70 μg/mL for CHRM and 20–140 μg/mL for PRED with a coefficient of determination (R 2) ≥0.9986. Repeatability and reproducibility (expressed as % RSD) were lower than 1.72 and 1.47%, respectively. The proposed HPLC method was demonstrated to be simple and rapid for the determination of CHRM and PRED in injection formulation, providing recoveries between 101.6–102.3%, whereas complete separation of degradation products, from analyte under investigation, provided the specificity of the proposed HPLC method.

Open access

Summary

The search for a complementary and alternative medicine has gained attention in recent years due to pronounced side effects and hazards of synthesized drugs. Hence, the exploration of novel bioactive components from traditionally used medicinal plants is necessary. Gnidia glauca is a semi-woody herb of the Thymelaeaceae family and is traditionally used as fish poison in India. Dried bark powder of G. glauca was subjected to physicochemical evaluation and then extracted with n-hexane, chloroform, ethyl acetate, ethanol, and water by successive Soxhlet extraction. All the extracts were tested for anticancer activity on human breast cancer cells (MCF-7 cell line) using sulforhodamine B colorimetric assay. Amongst all, ethanolic and ethyl acetate extracts were found to have significant cytotoxic activity. Further ethanolic extract was subjected to flash chromatographic separation for the isolation of a suitable marker, followed by its quantification by HPTLC. After identification, the compound was studied by infrared (IR) spectroscopy and high-resolution mass spectrometry to get insights into its structure.

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A fitoremediációs eljárások alkalmazása költséghatékony és környezetkímélő megoldást jelent a szennyezett területek helyreállítására. Korábbi kutatások alapján a bársonyvirágok alkalmasak lehetnek nehézfémmel szennyezett területek fitoremediációjára, azonban kevés információval rendelkezünk arról, hogy a fémeknek milyen toxikus hatása van ezekre a növényekre. Kutatásunk során két különböző kísérletet (egy előkísérletet és egy tenyészedény kísérletet) állítottunk be négy kiválasztott nehézfém (Cd, Pb, Cu, Zn) növényi bioakkumulációjának és toxicitásának vizsgálatára három különböző bársonyvirág fajon.

A csíranövényes előkísérlet alapján a kisvirágú bársonyvirág (Tagetes patula) volt a legkevésbé érzékeny az alkalmazott nehézfémekre, ezért ezt a növényt alkalmaztuk a tenyészedény kísérlet során. A tenyészedény kísérletben a növényeket a magyar jogszabályokban meghatározott talaj nehézfém szennyezettségi határérték 0-, 1-, 2- és 4-szeres dózisainak tettük ki. 120 napos talaj-növény interakció után mértük a növény növekedési paramétereit (hajtáshossz és tömeg, gyökérhossz és tömeg), valamint az esztétikai paramétereit (levelek és virágok száma, virágok átmérője). A növény hajtásának és a teszttalaj nehézfémkoncentrációit HNO3+H2O2 feltárás után atomabszorpciós spektrofotométerrel határoztuk meg.

Az eredményeink alapján a kisvirágú bársonyvirág képes a Cd és a Zn bioakkumulációjára a hajtásában, mivel 7-18-szor nagyobb koncentrációt mértünk a növény hajtásában, mint a teszttalajban. A Cu szintén akkumulálódott a hajtásban, azonban a növekvő Cu dózisok hatására a felhalmozódás mértéke csökkent. A növényi paraméterek (a Zn-terhelések kivételével) csak a legnagyobb dózisú nehézfém-terhelésekben csökkentek szignifikáns mértékben a kontrollhoz képest. A Zn szignifikánsan csökkentette a hajtáshosszt, a gyökér száraz tömegét, valamint a virágok átmérőjét már 400 mg kg-1 koncentráció esetén is.

Az eredményeink szerint a kisvirágú bársonyvirág alkalmas lehet kadmiummal, rézzel vagy cinkkel szennyezett talajok fitoremediációjára a vizsgált koncentráció-tartományokban. Alkalmazásuk városi területeken (pl. közparkokban, középületek és lakóházak kertjeiben, vagy utak melletti zöldfelületeken) megfelelő lehet, mivel ezek a növények a környezetet is szépítik.

Open access
Authors: Zsolt Kozma, Bence Decsi, Miklós Manninger, Norbert Móricz, András Makó and Brigitta Szabó

Összefoglalás

A folyamatalapú hidrológiai számításoknak és az azokra épülő vízminőségi, ökológiai elemzéseknek jelentős a bemenő adatigénye, ami a jövőben várhatóan tovább növekszik. A méréstechnológia rohamos fejlődésével a hidrológiai modellek bemenő adatai közül mára a szűk keresztmetszetet lokális és vízgyűjtő léptéken is a felszín alatti viszonyok, és elsősorban a talajok szivárgáshidraulikai tulajdonságainak számszerűsítése jelenti. A helyzetet felismerve a közelmúltban különböző módszertannal több talajtani, talajhidrológiai adatbázist is kidolgoztak. Kutatásunkban azt vizsgáljuk, hogy a 100 m felbontású hazai talajadatok és európai becslő algoritmusok alapján számított talajhidrológiai paraméterek (i) megbízható bemeneti adatforrást biztosítanak-e, és (ii) a korábban rendelkezésre álló adatállományokhoz képest javítják-e a hidrológiai számítások jóságát talajszelvény szintű vízforgalmi modellben.

Az Erdészeti Tudományos Intézet (NAIK ERTI) két mintaterületén (Fiad és Szalafő) mért meteorológiai és talajnedvesség-idősorok segítségével 5-5 darab talajszelvényszintű vízforgalmi modellváltozatot állítottunk fel Hydrus-1D környezetben. Ezek kizárólag a talajtani paraméterezésükben (réteghatárok helye, telített vízvezető képesség és retenciós görbe együtthatók) tértek el: a talajrétegek jellemzésére felhasználtuk (i) a kalibráció-validáció eredményeit (“legjobbnak vélt” verzió), (ii) a helyszíni mintavételből származó laboratóriumi méréseket, (iii) a mért talajtulajdonságok alapján, az európai becslő függvényekkel (EU-PTF) számított talajhidrológiai tulajdonságokat, (iv) a hazai DOSoReMI adatbázis alapján, az EUPTF- ekkel számított talajhidrológiai tulajdonságokat, illetve (v) az EUSoilHydroGrids térképeket. A modellváltozatokat a mért és számított talajnedvesség-idősorok összevetése (NSME, RMSE, R2) alapján értékeltük. Emellett összehasonlítottuk a számított vízmérlegeket is.

Az öt-öt modellváltozat esetében lényegesen eltért a mért-számított talajnedvességi idősorok illeszkedése. Fiadon egyedül a kalibráció adott elfogadható eredményt (NSME = 0.49), a másik négy változat kifejezetten gyengének bizonyult (három esetben NSME < 0). Szalafőn minden változat pozitív NSME-re vezetett, a kalibráció kiválónak tekinthető (NSME = 0.75). A várakozással ellentétben a mért talajhidrológiai paraméterekre épülő modellváltozatok adták a legrosszabb illeszkedést, míg a hatékonysági rangsorban a kalibrált modellek után az EU-SoilHydroGrids változatok következtek. A szimulációkból levezetett vízmérlegek Fiadon csak kevéssé, míg Szalafőn nagymértékben függtek a talajparaméterezéstől. A vizsgálat fontos tapasztalata, hogy a talajszelvény feltárás gyakorlata – érthető módon – elsősorban nem a hidrológiai modellezés szempontjaihoz igazodik, így az adatbizonytalanság forrása lehet. A vizsgálat eredményei alapján folytatjuk a Balaton vízgyűjtő talajhidrológiai paramétereinek 3D térképezését.

Open access
Authors: Sándor Molnár, Gyöngyi Barna, Eszter Draskovits, Rita Földényi, Hilda Hernádi, Zsófia Bakacsi and András Makó

Összefoglalás

Tanulmányunkban 27 különböző hazai talajszelvényben vizsgáltuk, hogy a talajok N2-BET fajlagos felületét mely talajtulajdonságok milyen mértékben befolyásolják.

Az egytényezős elemzések alapján elmondható, hogy a talajok mechanikai összetétele mutatja a legszorosabb kapcsolatot a fajlagos felülettel, az agyagtartalommal szoros pozitív kapcsolat van, ugyanakkor a homoktartalom növekedésével a fajlagos felület csökken. Igazolható a mész- és humusztartalom negatív előjelű nem túl szoros kapcsolata is a N2-BET felület értékekkel. A korrelációs vizsgálat gyenge pozitív kapcsolatot mutat a Hargitai-féle humuszstabilitási mutatóval. A talaj kémhatása és fajlagos felület közötti kapcsolatot nem tudtuk igazolni.

Vizsgáltuk a különböző talajtulajdonságok együttes hatását is a talaj N2-BET fajlagos felületére, valamint a talajok főtípusának, illetve a talajtípusoknak a szerepét. A teljes adatbázis alapján a N2-BET fajlagos felület kialakításában a legfontosabb tényezők az agyagtartalom, majd a humusztartalom, végül a mésztartalom. Amennyiben a talajok humuszanyagainak minőségéről is rendelkezünk információkkal, akkor az agyagtartalom, a humusztartalom, a humuszminőség és kémhatás azok a talajtulajdonságok, amelyek elsősorban felelősek a talajok a N2-BET fajlagos felületének kialakításáért. Megállapítottuk, hogy a fajlagos felületet becslő modellek pontossága tovább javítható a talajok rendszertani besorolásának (főtípus, típus), mint kategóriaváltozónak figyelembevételével. A talajok rendszertani helyének ismerete ugyanis számos olyan talajjellemzőről, azok együttes hatásairól nyújt közvetett információt, melyekről egyébként nem rendelkezünk közvetlen mérési eredménnyel.

Open access
Authors: Péter Ragályi, Botond Bernhardt, Márk Rékási, Eszter Draskovits, Sándor Molnár, Mónika Molnár, József Kutasi and Nikolett Uzinger

Összefoglalás

Az MTA Agrártudományi Kutatóközpont Talajtani és Agrokémiai Intézetének kísérleti állomásain nyírlugosi savanyú és őrbottyáni karbonátos homoktalajon szabadföldi kísérletben vizsgáltuk bioszén, bioszénre oltott és bioszénhez kevert saját hordozóján lévő baktérium oltóanyagos kezelés, valamint önmagában alkalmazott oltóanyag hatását kukorica elemösszetételére és elemfelvételére. A 4 kezelés 4 szinttel lett beállítva: 0, 3, 15 és 30 t ha-1 bioszén, valamint kombinációnként változóan 0-tól 2,1x1011–1x1013 CFU ha-1 oltóanyaggal. A kísérlet 4 ismétléssel 64 parcellát eredményezett mindkét helyen ismétlésenként véletlen blokk elrendezésben. A 20 m2-es (4x5 m) parcellák szélén körben 1 m szegélyt hagytunk, így a nettó parcella 6 m2 (2x3 m) területű volt. A műtrágyázás az ajánlott NPK ásványi műtrágya dózisának felével történt. A vegetációs időszak csapadékellátottsága messze elmaradt az 50-éves átlagtól és a kukorica tesztnövény optimális vízellátottságától, így a terméshozamok is alacsonyak maradtak, különösen a nyírlugosi talajon.

A növényminták vizsgálatokhoz való előkészítését, valamint elemösszetételét a hatályos Magyar Szabványok alapján határoztuk meg.

A növényi N és Mg koncentrációkban a kezelések nem okoztak változást. Az emelkedő bioszenes kezelések hatására a foszfortartalom a savanyú talajon enyhén nőtt a kukorica földfeletti részeiben, míg a karbonátoson alapvetően csökkent a szár+levélben, mely a bioszén+oltóanyag kezelésben szignifikáns volt. A K-tartalom látványosan, a nyírlugosi talajon átlagosan 61%-kal, az őrbottyánin 87%-kal nőtt a szár+levélben a legmagasabb dózisú bioszenes kezelések hatására. A növényi Ca-tartalom az őrbottyáni talajon eleve magasabb volt, ami a bioszenes kezelések hatására enyhén csökkent, a nyírlugosin viszont nőtt. A Zn-tartalom a szár+levélben mindkét termőhelyen csökkent az emelkedő bioszenes kezelések hatására. Az önmagában alkalmazott oltóanyag emelkedő adagjai nem okoztak változást a növényi összetételben.

A bioszenes kezelési dózisokkal többnyire emelkedő terméshozam miatt az elemhozamban markánsabb különbségek adódtak. A nyírlugosi talajon a kontrollhoz képesti növekmény a legmagasabb bioszenes kezelési szinteken N és K felvétel esetében 2-szerest meghaladó, a P, Ca és Mg felvételnél átlagosan sorrendben 67%, 73% és 57% a szár+levélben, a szemben pedig 2-3-szoros. Ez utóbbi a Zn hozamára is igaz volt, míg a szár+levélben csak enyhe növekedést mutatott. Az őrbottyáni talajon a szár+levélben 40% körüli N növekményt mértünk, a P, K, Ca felvételben elsősorban a szem esetében enyhe csökkenést tapasztaltunk, míg a Mg és Zn esetében gyakorlatilag nem volt hatása a bioszenet tartalamzó kezeléseknek.

A bioszénnel együtt alkalmazott oltóanyag egyes esetekben a legmagasabb növényi N, P és K felvételt eredményezte, így a két anyag kölcsönös pozitív hatása feltételezhető. Az önmagában alkalmazott oltóanyag szintén segítette a N felvételét.

Open access

Következtetések és összefoglalás

A majd’ 50 km2-es Bugaci-mintaterületen négy sekélyfúrásos vizsgálati programot végeztünk el. A vizsgálati eredmények közül az 1998–99-es mintázás nyomelem-adatainak eleddig hiányzó értelmezését adjuk közre.

A buckákon futóhomok, a laposokon agyagos–finomkőzetlisztes üledék található; ez utóbbi jelentős része karbonátiszap. Bár a laposok gyakorlatilag lefolyástalanok, a buckák–laposok helyzete nem állandó, így a rájuk jellemző üledékek is keverednek. A laposok alatti talajvízben és a laposok felszínén az időszakos tavakban a bepárlódás miatt megnő az oldott ion (só-) tartalom. A szedimentológiai és nyomelem-vizsgálatok alapján két sajátos környezetet érdemes kiemelni: a mai/archív felszíneket, amelyeken több a durvaszemcsés homok, valamint a semlyékek karbonátos, finomszemcsés üledékeit.

A felszínhez közel — a mészakkumuláció komponensei, azaz a Ca, Mg, Sr, Ba, CO3 2−, SO4 2−, PO4 3− (FÜGEDI et al., 2006) kivételével — az eolikus és a tavi üledékekben is minden vizsgált elemből jóval kevesebb van a Magyarországon általában szokásosnál. Ebben az értelemben a Bugaci-mintaterület jól reprezentálja Magyarország középső geokémiai nagytáját. Az ezen a nagytájon másutt megfigyelt törvényszerűségekkel teljes összhangban a karbonátok felhalmozódása közben az üledékekből valamennyi egyéb ion kimosódik: minél jobban oldódik, annál intenzívebben.

A Scheibler-módszerű, illetve áztatásos karbonáttartalmak csak nagyon lazán korrelálnak a Ca és Mg savoldható koncentrációival, mivel a kioldásos elemzéseket erősen befolyásolják egyéb tényezők (más sóásványok, az üledék diagenizáltsága). Az együtt előforduló, kiugróan nagy Cr- és Mo-tartalmakat automatikusan szennyezésnek kell tekinteni.

A tavi mésziszapokban a Ca/Sr arányt biogén folyamatok határozzák meg; ugyanezen iszapok kiugró S-tartalma bepárlódás eredménye. A mészakkumuláció elemcsoportja (Ca, Mg, Sr, Ba, CO3 2−, SO4 2−, PO4 3−) kivételével minden vizsgált elemből a Magyarország legnagyobb részén szokásosnál jóval kevesebb fordul elő. A tavi mésziszapok a Sr-tartalmak alapján megbízhatóan elkülöníthetők a mélyebb helyzetben kialakult mészakkumulációs szintektől.

A mintaterület talajai (főleg a homoktalajok) közepesen rézhiányosak és erősen cinkhiányosak.

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Authors: Amanda Fernandes de Medeiros, Maria Gabriela Ferreira Rocha, Alexandre Coelho Serquiz, Richele Janaína Araújo Machado, Vanessa Cristina Oliveira Lima, Fabiana Maria Coimbra de Carvalho, Izael de Sousa Costa, Bruna Leal Lima Maciel, Elizeu Antunes dos Santos and Ana Heloneida de Araújo Morais

Trypsin inhibitors have been described in peanuts and their derived industrialized foods, demonstrating diversity and thermoresistance. Given their most varied applications, these enzymatic protease inhibitors have been isolated and characterized for their potential use as bioinsecticides, herbal medicines, or medicines, but it is not simple. There are still no reports in the literature of the isolation and characterization of trypsin inhibitors in cultivar cavalo rosa (CCR) peanut, a common variety in Brazil. However, there are biological activities related to trypsin inhibitors from peanut-derived products. In this study, we isolated and characterized a novel trypsin inhibitor in CCR peanuts (Arachis hypogaea L.) under different processing conditions using a simple improved isolation. Raw and toasted peanut inhibitor was isolated by ammonium sulfate fractionation and trypsin-cyanogen bromide-activated Sepharose® 4B (CNBr-Sepharose® 4B) chromatography. The inhibitors from raw and toasted peanut were called AhTI1 and AhTI2, respectively, with potent anti-trypsin activity. Activity at different temperatures and pH was evaluated, and both samples were similarly stable under tested conditions. Minimum concentration for inhibition to occur (IC50) was 2.78 × 10−10 M and 2.39 × 10−10 M for AhTI1 and AhTI2, and inhibition constant (Ki) was 3.26 × 10−10 M and 1.54 × 10−10 M, respectively, showing non-competitive reversible kinetics. We concluded that AhTI1 and AhTI2 presented highly specific to trypsin and stable to toasting, different temperatures, and pH ranging. These are important characteristics in the process of developing bioinsecticides or biopharmaceuticals. Thus, this may be an interesting molecule, aiming at its biotechnological application, and it was obtained using a simple and easy isolation process.

Open access

Summary

Clerodendrum viscosum leaves are used in indigenous systems of medicines of mainland and maritime Southeast Asian countries for the treatment of fever, pain, dysentery, colic, and removal of Ascarids. The Clerodendrum species under study exhibit various phytochemical and morphological similarities. Therefore, it is very challenging to distinguish raw powdered materials used for therapeutic purposes. A validated high-performance thin-layer chromatography (HPTLC) method with 4 key markers, viz., 24ß-ethylcho-lesta-5,22E,25-triene-3ß-O-D-glucoside, clerodinin-A, 24ß-ethyl-cholesta-5,22E,25-triene-3ß-ol, and lupeol coupled with a chemometric analysis was used to distinguish 3 closely related Clerodendrum species, viz., C. inerme, C. multiforum, and C. viscosum. PRISMA approach was applied for effective HPTLC fingerprint development. The HPTLC-densitometry method was validated following the current International Conference on Harmonisation (ICH) guidelines. Taxonomic differentiation was established by fingerprint-based similarity analysis, a chemotaxonomic study using hierarchical clustering analysis (HCA), and principal component analysis (PCA) was done. HPTLC chromatogram similarity was calculated as correlation coefficient and congruence coefficient values, demonstrating poor similarities (0.26–0.86). However, PCA has resulted in 2 principal component (PC) loadings. PC1 separated C. multiforum, explaining 85.48% of variance mainly due to distribution of 2 triterpenoids. The present HPTLC method is coupled to marker-based quality determination of raw plants as well as discrimination of Clerodendrum species. Chemometric analysis based on 4 metabolites clearly establishes a practical identification of Clerodendrum species intended for therapeutic use.

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A sensitive and effective method based on a modified QuECHERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of polyoxin B in cucumber and soil using liquid chromatography tandem–mass spectrometry (LC–MS/MS) was developed and validated. Samples were extracted using 1% formic acid in ultrapure water and purified via reversed-dispersive solid phase extraction (r-dSPE) using C18. Recovery of polyoxin B ranged from 83.0% to 112.1% with relative standard deviation (RSD) (n = 5) of 3.0–5.2%. The limit of quantification (LOQ) and the limit of detection (LOD) were 0.01 and 0.003 mg/kg for cucumber and soil, respectively. The method was subsequently applied for real sample analysis. The dissipation experiments showed that half-lives of polyoxin B in cucumber and soil were 2.5–5.0 days. The terminal residues of polyoxin B at preharvest intervals (PHIs) of 3 days and 5 days in cucumber were less than 0.05 mg/kg. We therefore suggest that the developed method can be extrapolated to other agricultural crops or food for routine analysis. It also can be used to determine the PHIs. Moreover, these results will aid in establishing the maximum residue limit (MRL) for cucumber in China.

Open access

A simple and convenient reversed-phase high-performance liquid chromatography (RP-HPLC) method for simultaneous separation, identification, and determination of sodium metabisulfite and sodium benzoate in pharmaceutical formulation has been developed and validated. Chromatographic separation was achieved on RP column Zorbax Extend C-18 (150 × 4.6 mm i.d., 3.5 μm particles), and mixture of 0.1% phosphoric acid and acetonitrile in the ratio 62:38 (v/v) was used as a mobile phase. The flow rate was set at 1.0 mL/min with detection wavelength of 275 nm. The method was successfully validated according to International Conference on Harmonization (ICH) guidelines acceptance criteria. The method is selective, as no interferences were observed at retention times corresponding to these analytes. Results of regression analyses (r) and statistical insignificance of calibration curve intercepts (p) proved linearity of the method in defined concentration ranges for sodium metabisulfite and sodium benzoate (0.05–0.15 mg/mL). Relative standard deviations calculated for both analytes in precision testing were below the limits defined for active pharmaceutical ingredients (analysis repeatability: <2%; intermediate precision: <3%). Recovery values were between 98.16% and 101.94%. According to results of robustness testing, chromatographic parameters are not significantly influenced by small variation of acetonitrile content in mobile phase, column temperature, and flow rate. Finally, the method was applied for quantitative determination of investigated preservatives in real sample analysis.

Open access

An accurate, sensitive, and reproducible high-performance liquid chromatographic method with diode array detection has been developed for simultaneous determination of erythromycin, clarithromycin, and azithromycin residues in fish muscles. Analysis was carried out using a Shodex Asahipak high-performance liquid chromatography (HPLC) column, monitoring was at 210 nm and a mobile phase consisting of a mixture of acetonitrile and phosphate buffer (pH 11 ± 0.05) in the ratio of 60:40 (v/v). Solid-phase extraction method was used in samples extraction and purification. Recoveries were in the range 72.0–92.2% with relative standard deviation (RSD) from 2.3% to 8.3%. This method was validated for fish muscles in aquaculture following the commission decision 2002/657/EC criteria. It is demonstrated that the new method is robust for detection and quantification of the three macrolides residues. Decision limit (CCα) was from 214 to 228 μg/kg and capacity of detection (CCβ) was from 228 to 256 μg/kg.

Open access
Authors: Emese Ujj, György Lukácsy, Sándor Molnár, Ágota Horel, Györgyi Gelybó and Zsófia Bakacsi

Összefoglalás

A klímaváltozás hatására várhatóan nem csak a csapadék éves mennyisége, hanem az éven belüli eloszlása is változik, egyidejűleg megváltozhat annak az időszaknak a hossza, amelyben a talajok vízbefogadásra képesek. A talajnedvesség és csapadék idősoros adatok alapján vizsgálhatjuk a változó környezetei feltételek hatását a talajok vízgazdálkodására.

Jelen tanulmányban 2017. június–2018. május közötti időszakban a talajnedvesség-tartalom alakulását vizsgáltuk két eltérő domborzati adottságú szelvényben (teraszon és lejtőn) a tokaji Nagy-hegy déli lejtőjén elhelyezkedő Szarvas-dűlő szőlőültetvényen. Összehasonlítottuk a két mérőhely talajnedvességforgalmát, valamint vizsgáltuk a csapadékesemények hatását.

A teraszon lévő szelvény a csapadék jellemzően 65–99%-át közvetlenül befogadta, míg azonos csapadékeseményekre nézve ez az érték a lejtőn, az intenzívebb felszíni párolgás, valamint a felszíni lefolyás miatt csak 30–80%, szélsőséges esetben ennél is kisebb volt.

Az egyes rétegekben mért nedvesség profilok adataiból következtettünk a beszivárgás dinamikájára, a vízáteresztés mértékére. Azt tapasztaltuk, hogy telített állapotú szelvény esetén a terasz erősen tömődött rétege a vártnál kevésbé akadályozta a nedvesség mélyebb rétegek felé terjedését.

A teraszon lévő szelvény a tömődött rétegek ellenére összességében kedvezőbb vízháztartást biztosított, mint a meredek lejtő. A lejtő kedvezőtlen vízháztartását részben a nyári erőteljes párolgás, részben az egész évben jelentős felszíni lefolyás okozta. A szelvények vízkészletét 120 cm mélységig összegezve megállapítottuk, hogy a terasz teljes vízkészlete a vizsgált időszakban átlagosan több mint 20%-kal meghaladta a lejtőn feltárt szelvényét. Ez a különbség a nyári hónapokban 90–108 mm víztöbbletet jelentett a teraszon, a hasznosítható víz arányában kifejezve 62–88 mm-t. Nyáron, az eltérő száradás miatt augusztus végén volt a legnagyobb a terasz nedvességtöbblete (114 mm-rel), míg a téli–tavaszi időszakban az eltérő intenzitású feltöltődés okozott különbséget (legnagyobb eltérés: 159 mm).

A vízkészletek téli–tavaszi feltöltődése szempontjából más-más időszakra volt érzékeny a két szelvény. A terasz fagymentes időszakban, december végére gyakorlatilag elérte a maximális vízkapacitását, s ezt kisebb ingadozásokkal megtartotta április elejéig, melyet a február–márciusi fagyos időszak sem befolyásolt. A lejtő szelvénye fokozatosan töltődött fel, vízkészlete december közepétől a jellemzően fagyveszélyes január–februári időszakban is növekedett, majd április elejére „tetőzött”, 30 mm-re megközelítve a terasz vízkészletét. A feltöltődés menetében tapasztalt eltérés azt mutatja, hogy a terasz vízkészlete a korai feltöltődés miatt nem érzékeny a jellemzően fagyos február–márciusi időszakra. A lejtő vízkészletének feltöltődése azonban jóval belenyúlik a potenciálisan fagyos időszakba, vízkészletének alakulását a fagyos napok számának változása jobban befolyásolja.

Open access
Author: Bernd Spangenberg
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Summary

Extraction of crude drugs by using different solvents provides polarity-based fractions containing specific type of secondary metabolites. Carissa carandas L. fruits were extracted and fractionated, petroleum ether extract was processed by a fatty acid methyl ester (FAME) technique for characterization by gas chromatographymass spectrometry (GC-MS) analysis, and the remaining part was extracted with methanol for high-performance thin-layer chromatography (HPTLC) analysis, followed by simultaneous quantitative determination of protocatechuic acid and quercetin in methanolic fractions. A validated method for the simultaneous quantification of protocatechuic acid and quercetin was developed and is being reported for the first time in C. carandas L. fruits to the best of our knowledge. Petroleum ether and methanol fractions were found to be the best for the highest possible recovery of targeted analytes. Chromatographic elution of FAME compounds generated from petroleum ether extract was evaluated by GC-MS profiling. Nineteen fatty acid compounds were separated with the highest quantity of octacosanal (13.31%). On the other hand, a polar fraction was processed by HPTLC profiling. For achieving good separation, a mobile phase of toluene-ethyl acetate-formic acid (6:3:1; V/V) was used. Densitometric determination was carried out at 310 nm in the reflection/absorption mode. The calibration curves were linear in the range of 100-600 ng per spot for protocatechuic acid and quercetin. During the analysis, the dried raw material from C. carandas L. fruits showed the presence of protocatechuic acid (0.04%%) and quercetin (0.05%). The proposed method is simple, precise, specific, and accurate. The statistical analysis of the data obtained proves that the method is reproducible and selective, which can be used for the routine analysis of the reported phenolic compounds in crude drug and extracts. The simultaneous quantification of these phenolic compounds has not yet been reported in C. carandas L. fruits which may be utilized for the proper standardization of the drug.

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Authors: Hayford Ofori, Dhanushka Hettiarachchi, Tomislav Sostaric, Francesco Busetti and Mary C. Boyce

Summary

The potential of high-performance thin-layer chromatographic (HPTLC) fingerprinting in identifying differences in sandalwood essential oils from 5 sandalwood species, namely, Santalum album, Santalum spicatum, Santalum austrocaledonicum, Santalum panic-ulatum, Santalum lanceolatum, and a natural substitute for sandalwood, Osyris lanceolata, was explored. Variation was observed in the profile of bands (R F values and color) and peak intensity profiles displayed by the essential oils across and within the essential oils studied with some bands being unique to the individual species. The potential of HPTLC fingerprinting as a quality control tool in authenticating sandalwood oils in the sandalwood industry was demonstrated in the present study.

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Summary

The widespread use of the pharmaceutical metformin for diabetes therapy has led to finding its way into many surface waters up to the μg L−1 range and subsequently into different water treatment processes. In this study, metformin was treated with hypochlorite on the laboratory scale, and the resulting transformation products were investigated with the umu assay in a microtiter plate, where a genotoxic effect was detected. For the characterization of this genotoxic effect, the sample was separated using high-performance thin-layer chromatography (HPTLC), and 29 zones over the whole retardation area were extracted from the HPTLC plate with the thin-layer chromatography-mass spectrometry (TLC-MS) Interface. Then, the umu assay was performed again with each extracted zone, such that the genotoxic effect in the sample could be assigned to a certain zone. By the measurement of this effective zone with high-performance liquid chromatography with high-resolution mass spectrometry and by performing a non-target screening, the effective substance could be identified as a cyclic dehydro-1,2,4-triazole derivate with an intense yellow color. This substance formerly was found by Armbruster et al. (Water Research, 2015), which is a major transformation product of chlorine-treated metformin.

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Summary

Canscora perfoliata Lam., an important, traditionally used medicinal plant, belongs to the Gentianaceae family. Many pharmacological activities are reported for this plant; however, the major chemical constituents are not yet explored. The present study using chromatographic techniques led to the isolation of an active xanthonoid mangiferin from the whole plant. The structural identification was carried out by spectroscopic methods, such as ultraviolet (UV), Fourier transform infrared (FTIR), mass (MS) and nuclear magnetic resonance (NMR) spectroscopy. A modified high-performance thin-layer chromatographic (HPTLC) method was developed for the quantification of mangiferin in hydroalcoholic extract. The method was validated as per the International Conference on Harmonization (ICH) guidelines. Separation was achieved on silica gel 60 F254 HPTLC plates using ethyl acetate-methanol-formic acid-acetic acid-water (10:1:1:1:1, V/V). Detection and quantification were performed by densitometric scanning at 254 nm. Linearity for the compound was observed between 100-500 ng per spot (r 2=0.9979). The limit of detection and limit of quantification were 30 and 50 ng for mangiferin. The relative standard deviation for instrumental precision, intra-day precision, and inter-day precision were less than 1%. The percentage of average recovery was 97.7, indicating good reproducibility. The linear regression analysis data showed good linearity, repeatability, accuracy and specificity. The amount of mangiferin obtained from the extract was 1.4 ± 0.1% (w/w). This method can be used for routine quality control analysis and for the identification of the plant.

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Összefoglalás

A szerves szén igen jelentős összetevője a talajoknak. Meghatározza a talajok számos fizikai, kémiai, biológiai és nedvesség gazdálkodási tulajdonságát és sokrétű környezeti funkcióit, többek között termékenységét, vízszűrő-, és szolgáltató képességét, pufferkapacitását, vagy a biológiai sokféleség megőrzésében játszott szerepét. A modern osztályozási rendszerekben a szerves szén mennyiségi és mélységi megjelenése diagnosztikus egységek és magasabb rendszertani egységeknek is gyakran alapja.

Diagnosztikus szemléletű hazai talajosztályozási rendszerünk kidolgozásakor megvizsgáltuk a hazai genetikus osztályozás szervesanyagra vonatkozó kritériumait, részletesen elemeztük a TIM adatbázis adatait és figyelembe vettük a nemzetközi standardokat. Törekedtünk olyan diagnosztikai egységek, altípus és változati tulajdonságok meghatározására, melyek az osztályozás támogatásán túl, önmagukban is fontos információt szolgáltatnak a különböző alkalmazásoknak.

Eredményeink szerint a TIM adatbázis tanulmányozása, a szerzők saját talajleíró tapasztalata, továbbá a szervesszén-tartalomra irányuló adatigény indokolja további mennyiségi intervallumok meghatározását az osztályozás alacsonyabb (altípus és változati tulajdonság) szintjén.

Vizsgálatunk további fontos eredménye, hogy rámutat, a földes részre vonatkoztatott szervesszén-tartalom nem elég a feltalajok diagnosztizálására. A durva rész arány, a telítettségi viszonyok, a szín, a szerkezet további fontos kritériumok a feltalajok, illetve a felszíni diagnosztikai szintek definiálásában. Ugyanakkor a szerves szén mennyiségi-, és mélységi határértékeinek egységes, típustól független meghatározása fontos információt szolgáltat a talajok sok szempontú megítélésben.

Javaslatunkban a szervesszén-tartalomra vonatkozóan nyolc felszíni diagnosztikus talajszint, egy felszín alatti diagnosztikus talajszint, és egy diagnosztikus talajanyag került meghatározásra. Az osztályozás alacsonyabb szintjein további 5 kategória bevezetését javasoltuk a talajokban megjelenő szervesszén-tartalom részletesebb jellemzésének biztosítása érdekében.

A javasolt rendszerben összesen 20 altípus -, és 2 változati tulajdonságban jelenik meg szervesszén-tartalomra, vagy olyan diagnosztikus talajszintre vonatkozó követelmény, amely definíciójában a szervesszén-tartalom (is) szerepel.

Az egyes elemek azonos értelmezése lehetővé teszi a típustól független térbeli kiterjedésének meghatározását.

Open access
Authors: Szandra Baklanov, Ágota Horel, Györgyi Gelybó, Eszter Tóth, Márton Dencső, Emese Ujj and Imre Potyó

Összefoglalás

Jelen tanulmányban megvizsgáltuk a nitrogén átalakulással kapcsolatos nitrogén forgalmi folyamatok módosulását a nitrogénkötés-, a denitrifikáció-,- illetve a nitrifikációs aktivitás mérésével. A vizsgálatok alapanyagaként különböző földhasználati területekről származó talajmintákat használtunk fel. Az anyaggyőjtés helyszíneként a Balaton-felvidéken elterülő 21 km2 kiterjedéső vízgyőjtő terület szolgált. A talajmintákat hat földhasználati területről győjtöttük, úgy, mint tölgyesakácos, tölgyes, szőlő, szántó, gyümölcsös és rét.

A nitrogén forgalommal kapcsolatos laboratóriumi kísérletek sötét, és szabályozott hőmérsékleti körülmények között kerültek kivitelezésre, három hőmérsékleten (10 °C, 20 °C, 30 °C). Ennek célja az volt, hogy a vízgyőjtő területén előforduló hőmérsékleti körülményeket megfelelően tudjuk modellezni.

A potenciális nitrogénkötés vizsgálatánál pozitív korrelációt találtunk, vagy érdemi változást nem figyeltünk meg a hőmérséklet függvényében. A szántó, gyümölcsös illetve a rét talajmintáinál a nitrogénkötést mutató értékek csökkenését észleltük a hőmérséklet növelésével (10-20 °C). Az erdőből származó talajmintákban ugyanakkor nem tapasztaltunk változást. 30 °C hőmérsékleten szignifikáns növekedést kaptunk a nitrogénkötési potenciálok tekintetében (p < 0,05), a 10 °C, illetve 20 °C hőmérsékleten mért adatokkal összevetve.

A talajok nettó nitrifikációs potenciáljának vizsgálatakor negatív korrelációt figyeltünk meg magasabb hőmérsékleteken. A legnagyobb értékeket 10 °C hőmérsékleten, míg a legalacsonyabb eredményeket 30 °C hőmérsékleten mértük.

Az erdei talajok elemzése során nem jegyeztünk fel lényeges különbségeket a potenciális denitrifikációs folyamat különböző hőmérsékleteken mért eredményei között. A többi, eltérő földhasználati területről származó minták változó hőmérsékleten feljegyzett értékei között azonban jelentős eltéréseket tapasztaltunk (p < 0,05).

Összességében úgy találtuk, hogy egy terület mővelési módja jelentősen befolyásolhatja a talaj nitrogén forgalmának alakulását, különösen azokban az esetekben, amikor tápanyagutánpótlás is történik. A jelen tanulmány adatai alapján megállapítottuk, hogy a vizsgált vízgyőjtőn az emberi behatásoknak kisebb mértékben kitett területek nitrogén körforgalmi folyamatai kevésbé érzékenyek a hőmérsékleti változásokra.

Open access