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Chemistry and Chemical Engineering

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Abstract

In this study, we propose a simple, cost-effective, and sensitive high-performance liquid chromatography with both detection techniques such as diode-array detection and fluorescence detection (HPLC-DAD-FLD) for the determination of nesfatin-1 in fetal bovine serum samples. The limit of detection (LOD) and limit of quantification (LOQ) for nesfatin-1 were set at satisfactory values in the range 0.22–0.35 mg mL−1 and in the range 0.67–1.05 mg mL−1, respectively (at two different wavelengths (DAD) and at four different wavelengths (FLD)). Analyte concentrations were determined as the average value from fetal bovine serum matrix samples. The preliminary results show that the SPE procedure on Isolute Si-TsOH (SCX-3) could be used for further nesfatin-1 analyses in human serum samples. Both the SPE technique, chromatographic analysis with gradient elution mode and detection technique are fast and convenient.

Open access

Abstract

A new method for the analysis of four target flavonoids in two kinds of citrus samples by ultra-high performance supercritical fluid chromatography (UHPSFC) method was developed. Main variables affecting the UHPSFC separation were optimized, and under the optimized conditions the four target compounds (tangeretin, nobiletin, hesperetin and naringenin) can be separated within 10 min. The UHPSFC method allowed the determination of the four target compounds in the diluted stock solutions with limit of detection (LOD) ranging from 1.08 to 2.28 μg mL−1, and limit of quantification (LOQ) ranging from 1.45 to 4.52 μg mL−1, respectively. The coefficients of determination (R 2) of the calibration curves were higher than 0.9950. The recoveries of the four target compounds at three different concentrations were in the range of 82.4–117.6%. The validation results demonstrated that the proposed method is simple, accurate, time-saving and environment friendly, and it is applicable to a variety of complex samples such as medicine-food dual purpose herbs and functional foods.

Open access

Abstract

To overcome the problems of seasonality and geographical location in fruit production and processing, the production of aseptic semi-finished juice is an excellent solution. Even without refrigeration, aseptic pressing has a shelf life of more than a year, making it possible to produce finished products all year round. The production technology involves the addition of ascorbic acid to the pulp to fix or preserve colour. There is an increasing customer demand for ascorbic acid substitutes on the international market. In Hungary, one of the most important exports is aseptic sour cherry juice. In our work, ascorbic acid used for colour fixation was replaced by acerola concentrate. The anthocyanin content and colour coordinate values (L*, a*, b*, H, C) of aseptically filled sour cherry juice were determined and compared with the control sample during the 12 months of storage.

Open access

Abstract

Ziprasidone is the second generation antipsychotic drug with unique multipotent G-protein-coupled (GPCR) receptor binding profile. Since ziprasidone is a highly lipophilic and unstable compound, development of efficient method for a concurrent assay of ziprasidone and its main impurities was a very challenging task.

The UHPLC-MS/MS method that we developed for simultaneous determination of ziprasidone and its main impurities (BITP, Chloroethyl-chloroindolinone, Zip-oxide, Zip-dimer, and Zip-BIT) was compared with some other related HPLC-UV methods of our own and other authorship. An increase of the mobile phase pH value from 2.5 to 4.7 units in the examined analytical methods influenced elution order of the investigated compounds. It was found out that the UHPLC-MS/MS method is more selective and sensitive than the earlier developed HPLC-UV method. Similar to our earlier HPLC-UV method, the UHPLC-MS/MS method is linear with a correlation coefficient (r) above 0.99 for all the analysed compounds, but with a negligibly lower precision and accuracy. Finally, with shorter analysis time, smaller column size and reduction of solvent consumption, UHPLC-MS/MS is assumed as a greener method than HPLC-UV for the ziprasidone purity assay.

After transfer of the UHPLC-MS/MS method to the UHPLC-DAD system, suitability of the UHPLC-DAD method for routine control of ziprasidone and its main impurities is examined and confirmed based on the retained good selectivity, resolution and short analysis time.

Open access

As a means of assisting the selection of promising soil classification systems, a set of criteria were presented and tested. Inside the studied slightly saline plot World Reference Base (WRB) and Hungarian soil classification (HU) were compared at all four levels in terms of class separability, correlation to biomass, parsimony and homogeneity of classes. WRB surpassed HU in terms of the very important homogeneity of classes only, but HU performed better in terms of class separability, correlation to biomass and parsimony of classes. With many possible classification units WRB categorized the soil into a large number of classes, but 67% and 78% of them were single-profile classes at levels 3 and 4, respectively inside the ca 0.9 km2 area.

Open access

Abstract

Wild edible plants (WEPs) can be widely found in the world and defined as native species that grow naturally in their natural habitat. They have become part of the traditional food as human diet and used in folk medicine to treat diseases. They are very rich in terms of nutraceuticals. Melatonin is a natural hormone providing several benefits for human health. It has functions such as regulating growth and development and increasing tolerance to environmental stress factors in plants. It is stated that the serum melatonin level in humans increases after intake of foods containing melatonin. This study examined the presence of melatonin in wild grown cornelian cherry fruits by UFLC-FD and determined suitable extraction and chromatographic conditions. The optimum mobile phase, excitation/emission wavelength, and extraction solvent were determined as methanol: water: acetic acid, 275/345 nm, and methanol: water: HCl, respectively. Melatonin content in fruits ranged from 130.82 to 201.84 ng g−1 in fresh fruit.

Open access

Szarvasmarhatartó telepen alkalmazott ivarzásindukáló hormonok megjelenése a hígtrágyában

Appearance of on-farm bovine reproductive hormones in the resulting slurry

Agrokémia és Talajtan
Authors: Eduárd Gubó, Tibor Molnár, Pál Szakál, Dóra Pordán-Háber, Ákos Bede-Fazekas, and Judit Plutzer

A review of the international literature also found that the amount and the presence in slurry of oestrus inducer hormone preparations used in intensive dairy cattle production has not been investigated. In our study, we followed the path of 5 different sex-inducing drugs (alfaglandin, PGF, dinolytic, gonavet, ovarelin) including three active pharmaceutical ingredients (D-Phe6-Gonadorelin, Kloprostenol and Dinoprost-tromethamine) used in a cattle farm in Pest County from their use until their appearance in the slurry from 2017 to 2020. The study included a review of drug consumption and a seasonal analysis of the hormonal effects of slurry produced on the farm in quarterly cycles each year. We also tested separately the hormonal effects of the hormone preparations used on the farm. For the estrogenic effect tests, the yeast test with the human estrogenic receptor was used according to ISO 19040. Statistical evaluation of the results (Pearson correlation and Principal Component Analysis) was used to identify relationships between the use of sex inducers, the reproductive biology of the colony and the estrogenic effect of the slurry. We found that the estrogenic effects of slurry and sludge are strongly correlated. All three pharmaceuticals tested showed a strong correlation with the estrogenic effect of slurry/sludge. Our investigations confirm that slurry among other reasons due to its hormone and drug content shall be considered as a material that needs to be disposed of by new treatment methods before application to the field, because of its environmental and health risks.

Open access
Acta Chromatographica
Authors: Luis Alejandro Pérez-López, Norma Cavazos-Rocha, Cecilia Delgado-Montemayor, Noemí Waksman-Minsky, Marcelo Hernández-Salazar, and Omar J. Portillo-Castillo

Abstract

The analysis of phenolic acids (PAs) is of great importance, because they are frequently present in natural products and their derivatives, and these compounds also have multiple beneficial effects to human health. This work is focusing on the separation of seven PAs (caffeic acid, coumaric acid, gallic acid, ferulic acid, protocatechuic acid, sinapic acid, and syringic acid), in a reversed-phase liquid chromatographic (RP-HPLC) isocratic method using a hydrophilic deep eutectic solvent (DES) as a mobile phase additive. The analysis was carried out with a diode array detector. The used DES was composed by choline chloride and glycerol, and it was characterized by infrared spectroscopy. The combination of choline chloride:glycerol (1:4) added at 0.25% to mobile phase composed of 0.15% formic acid aqueous solution and methanol (80:20), showed the best separation for target analytes. The new proposed method was validated, and results indicated that the proposed method is linear, selective for almost all analytes, provided high sensitivity with limit of detection ranges from 0.009 to 0.023 mg mL−1, and has satisfactory precision and accuracy, with values of relative standard deviation of 0.24–2.65% and recoveries of 97.97–109%, respectively. Additionally, this method was successfully applied to simultaneous determination of phenolic acids in three kinds of samples of powder to prepare lemon flavour drink enriched with black tea extract.

Open access

Abstract

Dendrobium nobile and Dendrobium officinale as the main varieties of traditional Chinese medicine Dendrobium are widely used in clinic. The study aimed to systematically explore chemical constituents and their antitumor effect of D. nobile and D. officinale by ultra-performance liquid chromatography coupled with ion trap time-of-flight mass spectrometry (UPLC-IT-TOF), network pharmacology and cancer cell experiments. D. nobile extract and D. officinale extract could significantly inhibit the proliferation of human lung cancer A549 cells, human liver cancer HepG2 cells and human breast cancer MCF-7 cells in the dose-dependent manner (P < 0.05), the antitumor effect of D. officinale extract was stronger than that of D. nobile extract at the same drug concentration. A total of 40 chemical constituents of D. nobile and D. officinale including phenanthrenes, bibenzyls and other types of compounds had been identified by UPLC-IT-TOF, LCMSsolution and MetID software according to retention times, accurate mass, MSn fragmentation, reference compounds and natural product databases. Phenanthrenes with good antitumor activity were mainly present in D. nobile, bibenzyls were the main compounds of D. officinale. Integrated networks of Herb-Compounds-Targets-Cancer revealed that gigantol, moscatilin, tristin, moscatin and densiflorol B were regarded as key antitumor compounds of D. nobile and D. officinale, D. nobile and D. officinale shared 7 targets accounting for 70% of the antitumor core targets, more than half of their antitumor KEGG pathways were similar. The results of molecular docking and western blotting experiments indicated that the antitumor mechanisms of D. nobile and D. officinale may be through inhibiting PI3K-Akt and HIF-1α signaling pathways.

Open access

Cover crops serve as an essential source of nutrients in the soil and generally improve the soil’s properties. Cover crops’ production is considered a benefit of the soil quality; by protecting the soil from erosion, reducing the weeds and the so-called soil-borne plant pathogens. Different varieties of cover crops can be cultivated such as legumes, non-legumes, brassica, and grass-type of plants with a variability of the symbiosis. A pot experiment was carried out with five cover crops, as non-symbiont (Brassica carinata B.c.), single-symbiont with arbuscular mycorrhiza fungi (AMF) (Phacelia tanacetifolia P.t., Avena strigosa A.s.) and double symbiont with AMF and nitrogen-fixing bacteria (Vicia benghalensis V.b., Vicia faba V.f.) crops; and a mixture of the five species, placed in sandy soil (arenosol) in plastic pots (5000 g soil) in 4 repetitions. One of the pots with mixed cover crops was inoculated by AM fungi industrial product. We measured soil biological activity of dehydrogenase (DHA) and fluorescein-diacetate (FDA) enzymes, the frequency of AM fungi (F%), the all protein, glomalin content and electrical conductivity (EC) of the soils. Mixture of all the cover crops resulted maximum EC and significantly enhanced the enzymatic, DHA, FDA activities in comparison with single plants. Mycorrhiza colonization frequency was high in all cover crops except the mustard (B.c.), as nonsymbiont. Vetch (V.b.), as double symbiont was responding very positively to AMF inoculation, and enhanced the performance of its growth. It was found in the pot experiment, that vetch, has the highest capacity to retain soil-protein, glomalin concentration, as well. The mixture of five cover crops could be suggested to use, due to the synergistic positive performance of the individual crops, and the better functioning of beneficial fungal / bacterial symbiosis.

Open access
Agrokémia és Talajtan
Authors: László Simon, Marianna Makádi, Zsuzsanna Uri, Szabolcs Vigh, Katalin Irinyiné-Oláh, György Vincze, and Csilla Tóth

Open-field small plot long-term experiment was set up during 2011 with willow (Salix triandra × S. viminalis ‘Inger’), grown as a short rotation coppice energy crop in Nyíregyháza, Hungary. The sandy loam Cambisol with neutral pH was treated three times (2011, 2013, and 2016) with 15 t ha–1 municipal sewage sludge compost (MSSC) and with 600 kg ha–1 (2011, 2013) or 300 kg ha–1 (2016) wood ash (WA). In 2018 the MSSC-treated plots were amended with 7.5 t ha–1 municipal sewage sediment (MSS), and 300 kg ha–1 WA. MSSC and WA or MSS and WA were also applied to the soil in combinations during all treatments. Control plots remained untreated since 2011. Repeated application of wastewater solids (MSSC, MSS) and wood ash (WA) significantly enhanced the amounts of As (up to +287%), Ba, Cd (up to +192%), Cu, Mn, Pb, and Zn in the topsoil of willows. The combined application of MSSC+MSS+WA resulted in significantly higher Mn and Zn and lower As Ba, Cd Cr, and Pb concentrations in topsoil than MSSC+MSS treatment of soil without WA. Nitrogen concentrations in leaves of treated plants were generally slightly lower or similar to control. All soil treatments significantly enhanced the uptake or accumulation of nutrient elements (Ca, K, Mg, P) and potentially toxic elements (As, Ba, Cd, Cr, Cu, Mn, Ni, Pb, and Zn) in the leaves of willows during 2018, 2019, and 2020. Significantly higher Mn or Zn concentrations were measured in MSSC+MSS+WA than in MSSC+MSS treatments. Significant amounts of Cd (up to 1.11 mg kg–1) or Zn (up to 183 mg kg–1) can be translocated (phytoextracted) from a soil amended with wastewater solids or wood ash to willow leaves. In 2018 the treatments decreased the chlorophyll fluorescence values, while in 2019 and 2020 the light adapted fluorescence yield (Y) values were higher in treated than in control plants.

Open access

In this study PTEs, [potentially toxic elements (Cr, Cu, Mn, Ni, Pb, and Zn)] were investigated in the upper layer of floodplain soils that occurred as a result of accident in the area of two mine tailings in Northwestern Romania. A large amount of sediment was deposited on the soil of floodplains along the Hungarian section of River Tisza, which could represent a threat to the environment. Floodplain soil samples were collected from four locations in Hungary from an area of the river stretching to about 250 km. BCR (Bureau Communautaire de Référence) sequential extraction method was used to analyze both post-flood and present samples. Most of the analyzed elements (Cd, Cr, Cu, Ni, Pb, Zn) were found in the residual fraction, but there is a notable soluble amount in hydroxylammonium chloride extractable fraction. The results allow a comparison of the changes that have taken place over time, in addition to serving as a basis for further studies.

Open access

Abstract

As per the World Health Organization, 10% of medicines in low- and middle-income nations are of poor quality and pose a huge public health risk. The development and implementation of cost-effective, efficient and quick analytical methods to control the quality of these medicines is one of the immediate strategies to avoid such a situation. Hence, the main goal of this study was to develop and validate a simple, specific and precise new RP–HPLC method for simultaneous analysis of amoxicillin, ampicillin and cloxacillin in pharmaceutical formulations. The chromatographic analysis was achieved using Shodex C18 (250 × 4.6 mm, 5 μm) column with UV detection at 225 nm. The mobile phase was a gradient mixture of 30 mM phosphate buffer, pH 4.0 (mobile phase A) and acetonitrile (mobile phase B). Efficient separation of the three drugs was obtained using the final optimized chromatographic conditions. The developed method was validated for its specificity, linearity, precision, accuracy and robustness as per the ICH guidelines. The validation results showed that the method was specific, linear, precise, accurate and robust for the simultaneous determination of the three drugs. The developed method was applied to determine the content of the three drugs in pharmaceutical formulations. The assay results of the preparations showed that their drug content was within the pharmacopeial limit stipulated for each drug product. It can be concluded that the proposed method is suitable for simultaneous determination of amoxicillin, ampicillin and cloxacillin in pharmaceutical formulations in industries and regulatory laboratories.

Open access
Agrokémia és Talajtan
Authors: Norbert Túri, János Körösparti, Balázs Kajári, György Kerezsi, Mohammed Zain, János Rakonczai, and Csaba Bozán

Due to extreme meteorological and soil hydrological situations the agricultural production security is highly unpredictable. To release the extent and duration of inland excess water (IEW) inundations or two-phase soil conditions during the period intended for cultivation, subsurface drainage (SD) has been used as a best practice in several countries. SD interventions took place between 1960’s and 1990 in Hungary. After 1989, land ownership conditions changed, thus professional operation and the necessary maintenance of the SD networks designed as a complex system became insignificant. In this paper, our aim was to present the IEW hazard in one of the most equipped areas by SD in Hungary. The occurrence frequency of IEW inundations in drained and non-drained (control) areas in different time intervals were compared. According to our results, we could state that the frequency of IEW on the subsurface drained areas was moderately lower in only a few periods compared to the control areas. IEW hazard of the arable areas at the Körös Interfluve was classified as nonhazarded in 52.7% of the area. Another 38.2% were moderately hazarded, 8.26% of the lands were meanly hazarded and less than 1% were highly hazarded area by IEW.

Open access

Abstract

Purpose

Development and validation of a selective analytical method to accurately and precisely quantify nicotine and cotinine levels in rat's plasma after exposure to tobacco cigarettes and tobacco water-pipe.

Methods

An easy HPLC-Photodiode-Array Detection (PDA) method was developed and validated for simultaneous determination of nicotine and cotinine levels in plasma of 15 rats (10 rats after tobacco products exposure and 5 control rats). Nicotine and cotinine were extracted in one step from plasma using acetonitrile and concentrated to lowest volume using nitrogen stream.

Results

The developed method offered a rapid analysis time of 14 min with single step of analytes extraction from rat's plasma with recovery percentage range between 93 and 95% and excellent linearity with correlation factor more than 0.994 with analytical range between 50 and 1000 ng mL−1 and LOD of 25 ng mL−1 and 23 ng mL−1 for nicotine and cotinine, respectively. The analysis of rat's plasma after 28 days of exposure to tobacco cigarettes and tobacco water-pipe revealed that the average concentrations of 376 ng mL−1 for cotinine and 223 ng mL−1 for nicotine were obtained after tobacco cigarettes exposure, and 220 ng mL−1 for cotinine and 192 ng mL−1 for nicotine after tobacco water-pipe exposure.

Conclusion

Higher nicotine and cotinine levels were found in plasma after tobacco cigarettes exposure than water-pipe exposure which may have potential undesirable effects on passive smokers in both cases.

Open access

The Westsik’s long-term crop rotation experiment was set up in 1929 at the Nyíregyháza Experimental Station (NE Hungary) on a slightly acidic Arenosol. Besides fallow crop rotation (CR), effects of different organic amendments (lupine as green manure, lupine as main crop, straw manure, and farmyard manure (FYM) were studied with or without N or NPK-fertilizers. The crop rotation consisted of rye, potato, lupine, and oat with common vetch. The soil of potato plots was analysed in 2019 at the 90th anniversary of Westsik’s crop rotation experiment.

The following chemical and microbiological soil parameters were determined: soil pH, available nutrient contents, organic carbon (OC) and nitrogen (ON) contents, microbial biomass carbon (MBC) and nitrogen (MBN), soil respiration, net nitrification, and activity of some soil enzymes.

In the CRs, the soil pHH2O varied from acidic to weakly alkaline and it largely differed from pHKCl. The results showed a significant increase in the content of nitrate, available phosphorus and potassium in most of the fertilized plots. Applying straw, green manure, or FYM significantly increased the OC and ON contents. The total count of cultivable bacteria increased upon the application of the organic manures. Combined application of straw manure and N-fertilization heavily improved the abundance of the microscopic fungi.

While all the applied organic manures significantly enhanced the MBC, the MBN increased only by the green manure amendment. Our results revealed higher soil respiration rate in the plots receiving straw or FYM than in the control. Both green manure and FYM elevated the net nitrification rate. Phosphatase, saccharase, urease, and dehydrogenase enzymes showed a hesitating response to the manure application in the different CRs.

The soil respiration and dehydrogenase activity correlated to most of the measured chemical parameters. Among microbiological properties, the MBC and MBN, as well as dehydrogenase and other enzyme activities displayed a positive correlation. Results proved the need for the exogenous application of organic matter in the form of organic manures to enhance the nutritional status and health of the soil.

Open access

Greenhouse plastic contaminations in agricultural soils were studied to quantify and examine the macroplastic and microplastic contaminants on the soil surface, soil profile, and groundwater under greenhouse farmland. Random sampling was used to select three areas in a greenhouse farm where macroplastic and microplastic data were collected. Four composite samples were collected from shallow (0–20 cm) and deep (20–40 cm) soils for each sampling point, respectively. Three soil profiles were dug, and samples were collected at intervals of 20 cm. Groundwater samples were also collected from the same profiles at a depth of 100 cm. Microplastics were extracted using predigestion of organic matter with 30% H2O2 and density separation with ZnCl2. The total mass of macroplastics in the greenhouse farmland was 6.4 kg ha–1. Polyethylene and polyvinyl chloride were the dominant plastic structures, and the dominant sizes were 1–5 and 0.5–1.0 cm, respectively. Overall, the average abundance of microplastics in the greenhouse soil was 225 ± 61.69 pieces/kg, and the dominant size structure was 2–3 mm. The average microplastic concentrations at depths of 0–20 and 20–40 cm were 300 ± 93 and 150.0 ± 76.3 pieces/kg, respectively. The average microplastic concentration in the groundwater was 2.3 pieces/l, and fibers were the dominant plastic structure. Given that microplastics were found in greenhouse soil, soil profiles, and groundwater, we recommend the careful cleaning and disposal of plastics on greenhouse farmland and further research to shed light on the level of microplastic contamination in the soil profiles and groundwater.

Open access

Abstract

A precise, sensitive, specific and accurate stability indicating densitometric method was developed and validated for alpha-lipoic acid (ALA) in bulk and capsule dosage form. The study employed pre-coated silica gel 60F254 TLC plates as stationary phase and toluene: chloroform: methanol: formic acid (5:3:1:0.05; v/v/v/v) as mobile phase. The developed method furnished compact spots of alpha-lipoic acid (Rf 0.28 ± 0.05) after derivatization, offered good linearity in range 80–400 ng/spot with correlation coefficient of 0.998. The values for detection and quantitation were found 18.022 and 54.612 ng/spot respectively. ALA was subjected to stress degradation studies and total 13 degradation products were resolved. Thus, the proposed method offered good results according to ICH guidelines, and can be used for identification, routine quantitative determination as well as for monitoring the stability of ALA in bulk and in capsules.

Open access

Abstract

Modafinil has a strong and long-lasting awakening effect. Short-term use can improve cognitive and work efficiency. Therefore, it has been known to be abused by students and parents as a “smart drug.” It is in the first category of psychotropic drugs and strictly controlled. To detect modafinil in rat plasma and study the differences in the pharmacokinetics of modafinil between oral and sublingual administration in rats, an ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed. Rats were injected with modafinil by oral gavage and sublingual vein, respectively, blood was collected within a certain period, and the plasma was obtained by centrifugation. Midazolam was used as the internal standard, and the concentration of modafinil in the plasma was determined by UPLC-MS/MS, where a drug-time curve was created to calculate the pharmacokinetic parameters. The standard curve for modafinil ranged from 1 to 2000 ng mL−1 with good linearity. The intra-day accuracy of modafinil was between 86% and 104%, and the intra-day accuracy was between 90% and 103%. Intra-day precision (RSD%) was less than 15%, inter-day precision (RSD%) was less than 15%. The matrix effect was between 93% and 102%, and the recovery was greater than 91%. The UPLC-MS/MS method established in this work has good selectivity and high sensitivity, and the UPLC-MS/MS method was successfully applied to the pharmacokinetics of modafinil by oral gavage and sublingual injection in rats. The bioavailability of modafinil was calculated to be 55.8%.

Open access
Acta Chromatographica
Authors: Qishun Liang, Tianyu Chen, Lvqi Luo, Yizhe Ma, Congcong Wen, and Xueli Huang

Abstract

A UPLC-MS/MS method was developed to determinate curdione in the mouse blood, and the pharmacokinetics of curdione in mice after intravenous (5 mg kg−1) and oral (20 mg kg−1) administration were studied. The HSS T3 column was used for separation, and column temperature was set at 40 °C. Multiple reaction monitoring (MRM) mode were used for determination of curdione. Blood samples were taken from the caudal vein of Institute of Cancer Research (ICR) mice after administration of curdione. It showed a good linear relationship in the range of 1–500 ng mL−1 (r > 0.998); the intra-day precision was <13%, the inter-day precision was <15%, and the accuracy was 90%–105%, the recovery was >77%, and the matrix effect was 97%–107%. The half-life was relatively short, and the bioavailability was 6.5%. The developed method was suitable for the pharmacokinetics of curdione in mice.

Open access

Abstract

A rapid and simple ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method was developed and validated for simultaneous determination of six analytes from the Eleutherococcus senticosus (Rupr. & Maxim.) Maxim. leaves (ESL) in beagle dog plasma for the first time, including 3-O-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranoside-29-hydroxy oleanolic acid, 3-O-β-d-glucopyranosyl-(1→2)-α-l-arabinopyranoside-29-hydroxy oleanolic acid, 3-O-β-d-glucopyranosyl-(1→2)-α-l-arabinopyranosyl-30-norlean-12,20 (29) –dien-28-olic acid, ciwujianoside E, guaianin N, and eleutheroside K. The chromatographic separation was performed using an ACQUITY UPLC BEH C18 column (2.1 × 100 mm, 1.7 μm) using a gradient elution way with a mobile phase of acetonitrile-water containing 0.1% formic acid. Analytes were detected on a triple-quadrupole mass spectrometer equipped with an electrospray ionization (ESI) source with multiple reaction monitoring (MRM) mode. Calibration curves were all linear (r ≥ 0.9933) over the concentration range. The mean extraction recoveries and matrix effect of analytes and I.S. were ranged from 80.26% to 98.32% and from 91.27% to 111.67%, respectively. The intra-day and inter-day precision were ranged from 2.20% to 14.81%, and the accuracy range was 1.60–14.60%. The analytical method was successfully applied for the pharmacokinetic characteristics of the six analytes in beagle plasma after oral administration of ESL extracts. The T 1/2 of six analytes was more than 3.09 ± 0.78 h.

Open access

Abstract

Epilepsy is one of the most prevalent neurological conditions and antiepileptic drugs are the mainstay of epilepsy treatment. High variation in pharmacokinetic profiles of several antiepileptic drugs highlights the importance of therapeutic drug monitoring to estimate pharmacokinetic properties and consequently individualize drug posology. In this work, a simple, rapid and robust liquid chromatography-tandem mass spectrometry method was developed for simultaneous quantification of carbamazepine and its metabolite carbamazepine-10,11-epoxide, gabapentin, levetiracetam, lamotrigine, oxcarbazepine and its metabolite mono-hydroxy-derivative metabolite, phenytoin, topiramate, and valproic acid in human plasma for therapeutic drug monitoring. d 6-Levetiracetam, d 4-gabapentin and d 6-valproic acid were used as internal standards. After addition of internal standards along with two-step protein precipitation and dilution sample preparation, plasma samples were analyzed on a C18 column using a gradient elution in 5 min without interference. The calibration curves were linear over a 100-fold concentration range, with determination coefficients (r 2) greater than 0.99 for all analytes. The limit of quantification was 0.5 μg mL−1 (0.1 μg mL−1 for oxcarbazepine, 2 μg mL−1 for levetiracetam, and 10 μg mL−1 for valproic acid) with precision and accuracy ranging from 3% to 9% and from 94% to 112%, respectively. Intra- and inter-day precision and accuracy values were within 15% at low, medium and high quality control levels. No significant matrix effect was observed in the normal, hemolyzed, lipemic, and hyperbilirubin blood samples. This method was successfully used in the identification and quantitation of antiepileptic drugs in patients undergoing mono- or polytherapy for epilepsy.

Open access

Abstract

A rapid, selective, and precise high performance thin layer chromatographic method was developed and validated for the simultaneous analysis of paracetamol, caffeine, phenylephrine and chlorpheniramine in tablets. The chromatographic analysis was carried out on glass plates pre-coated with silica gel 60 F254 as a stationary phase. The optimized mobile phase was methanol : n-butanol : toluene : acetic acid (8:6:4:0.2 v/v). TLC chamber of 10 × 20 cm was used with saturation time of 15 min. The retardation factor (RF) for chlorpheniramine, phenylephrine, caffeine and paracetamol was found to be 0.15 ± 0.02, 0.29 ± 0.02, 0.50 ± 0.02, 0.68 ± 0.02 respectively. Detection was carried out at 212 nm. Validation study was done following ICH Q2 (R1) guideline. The regression data for the calibration plots showed good linear relationship with R 2 = 0.997 over the concentration range of 300–1,500 ng band−1 for caffeine, R 2 = 0.996 over the concentration range of 100–500 ng band−1 for phenylephrine, R 2 = 0.996 over the concentration range of 200–600 ng band−1 for chlorpheniramine, R 2 = 0.998 over the concentration range of 400–2,400 ng band−1 for paracetamol. The method was validated for precision, accuracy and recovery. Minimum detectable amounts were found to be 304.9 ng band−1, 87.88 ng band−1, 117.18 ng band−1 and 143.06 ng band−1 for caffeine, phenylephrine, chlorpheniramine, and paracetamol respectively while the limit of quantification was found to be 923.95 ng band−1, 266.32 ng band−1, 355.11 ng band−1, and 433.53 ng band−1 in the same order. The method was successfully applied to analyze two marketed tablets in a selective and reproducible manner.

Open access

Egy köles tájfajta műtrágya-reakciójának vizsgálata

Examination of the reaction to fertilization of regional millet variety

Agrokémia és Talajtan
Authors: Zsembeli Zsadány, Sinka Lúcia, Tüdősné Budai Júlia, Kovács Györgyi, Tuba Géza, and Zsembeli József

Kutatómunkák általános célja olyan kísérletek végzése, amelyek feltárják az adott régióban perspektivikusan termeszthető fajták, illetve tájfajták optimális műtrágyázási igényeit. Tanulmányunkban a Karcagon nemesített és fenntartott ’Maxi’ köles tájfajta tápanyagreakciójának vizsgálatából származó eredményeinket mutatjuk be a módosított Országos Műtrágyázási Tartamkísérlet (OMTK) 2017. évi és az annak figyelembevételével 2021-ben beállított Műtrágyázási Kísérleti Kert (MKK) adatai alapján. A kísérleteket Karcagon, a MATE Karcagi Kutatóintézetben, egy mélyben szolonyeces réti csernozjom talajon állítottuk be. 2017-ben a módosított OMTK kezelései 4 nitrogén (40, 80, 120, 160 kg ha 1), 4 foszfor (0, 40, 80, 100 kg ha 1) és 3 kálium (0, 60, 90 kg ha 1) dózis kombinációjából adódtak, illetve volt egy műtrágyázás nélküli abszolút kontroll. 2021-ben az MKK kezelései 3 nitrogén (40, 80, 120 kg ha 1), 3 foszfor (0, 40, 80 kg ha 1) és 2 kálium (0, 60 kg ha 1) dózis kombinációját foglalták magukba, illetve mindegyik parcella felére növénykondicionáló szert juttatunk ki. A termesztett növény mindkét évben a karcagi nemesítésű ’Maxi’ kölesfajta volt. A különböző kezeléscsoportok termésre gyakorolt hatásának statisztikai értékelését egytényezős varianciaanalízissel végeztük el. Mindkét vizsgálati évben a 80 kg ha 1 hatóanyag mennyiségben kijuttatott nitrogén műtrágyázás bizonyult a leginkább megfelelőnek. A magas foszfor dózisok a legtöbb esetben termésdepresszióhoz vezettek. Eredményeink alapján még a közepes – jó kálium ellátottságú karcagi talajokon is hasznos lehet a kálium kijuttatása, bár a káliumtrágyázás termésre gyakorolt hatását a varianciaanalízis nem igazolta. Az Algomel PUSH szerrel végzett növénykondicionálás statisztikailag is igazolhatóan, mintegy 10%-kal növelte a termés nagyságát. Kutatómunkánk folytatásával pontosabban meghatározható lesz számos tájfajta tápanyagreakciója és fajtaspecifikus, a helyi agroökológiai viszonyokat is figyelembe vevő tápanyag dózisok és kombinációk ajánlhatók a gazdálkodóknak.

The general objective of our research is to carry out experiments that are suitable to reveal the optimal fertilization demand of regionally bred or potentially producible crop varieties for a specific region. In our recent study, the results gained from the examination of the nutrient reaction of the regional millet variety ‘Maxi’ bred and maintained in Karcag are introduced based on the data originating from the modified Long-term National Fertilization Experiments (OMTK) in 2017 and from the Fertilization Experimental Garden (MKK) established at Karcag in 2021. Both experiments were set up in the MATE Research Institute of Karcag on a meadow chernozem soil salty in the deeper layers. In 2017, there were 4 nitrogen (40, 80, 120, 160 kg ha−1), 4 phosphorus (0, 40, 80, 100 kg ha−1), and 3 potassium (0, 60, 90 kg ha−1) dosage combinations applied and one unfertilized absolute control in the OMTK trial. In 2021, in the MKK experiment, treatments involved 3 nitrogen (40, 80, 120 kg ha−1), 3 phosphorus (0, 40, 80 kg ha−1), and 2 potassium (0, 60 kg ha−1) dosage combinations, furthermore, on half of the plots a plant conditioner was sprayed. Millet variety ‘Maxi’ bred at Karcag was the indicator crop in both years. For the statistical analysis of the effect of the various treatment groups on yields, One-way ANOVA tests were used. We considered the 80 kg ha−1 nitrogen substance dose the most suitable in both years. High dosage of phosphorus application resulted in yield depression in most of the cases. Based on our results, potassium fertilization can be effective even on the soils of Karcag with medium to good potassium supplies, though the analysis of variance did not justify the effect of K-fertilization on yields. The 10% yields increase due to plant conditioning with Algomel PUSH was statistically proven. By continuing or research, the reaction to fertilization of several regional crop varieties can be determined more precisely, and variety-specific nutrient doses and combinations can be determined and suggested to the local famers taking the regional agri-ecological conditions into consideration.

Open access
Acta Chromatographica
Authors: Hao-ran Dai, Ya-hui Hu, Jia-yi Long, Ying Xia, Hong-li Guo, Jing Xu, Xuan-sheng Ding, Jing Chen, Xiao-peng Lu, and Feng Chen

Abstract

Perampanel (PER) is the first clinically available selective antagonist of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor approved globally for the treatment of epilepsy. Studies have recently underlined the significant association between dose-exposure-effect-adverse events of PER in patients with epilepsy, so the therapeutic drug monitoring (TDM) of PER is critical in clinical practices, especially for pediatric patients with drug-resistant epilepsy. Due to several limits in previous published analytical methods, herein, we describe the development and validation of a novel liquid chromatography tandem mass spectrometry (LC-MS/MS) method for monitoring PER in human plasma samples. Protein precipitation method by acetonitrile containing PER-d5 as internal standard was applied for the sample clean-up. Formic acid (FA, 0.2 mM) in both aqueous water and acetonitrile were used as the mobile phases and the analyte was separated by an isocratic elution. Qualification and quantification were performed under positive electrospray ionization (ESI) mode using the m/z 350.3 → 219.1 and 355.3 → 220.0 ions pairs transitions for PER and PER-d5, respectively. Potential co-medicated anti-seizure medications (ASMs) have no interference to the analysis. Calibration curves were linear in the concentration range of 1.00–2,000 ng mL−1 for PER. The intra- and inter-batch precision, accuracy, recovery, dilution integrity, and stability of the method were all within the acceptable criteria and no matrix effect or carryover was found. This method was then successfully implemented on the TDM of PER in Chinese children with drug-resistant epilepsy. We firstly confirmed the apparent inter- and intra-individual PER concentration variabilities and potential drug-drug interactions between PER and several concomitant ASMs occurred in Chinese pediatric patients, which were also in line with previous studies in patients of other race.

Open access

Abstract

Gluten-free (GF) breads are often described with low quality, rapidly staling, dry mouthfeel and crumbling texture attributes. In lack of recent texture profile data on commercially available, preservative-free, freshly-baked GF bread, this study aimed to compare different types of GF products with their wheat-based counterparts during a 4-day-long storage test. Texture analysis data showed that GF loaves performed better than or comparable to the wheat-based ones in hardness, springiness and cohesiveness. Among sensorial properties mouth-feel, softness and aroma were evaluated as significantly better or similar for GF versus wheat-based products. GF cob had a saltier taste, which reduced the flavour experience. Both the texture results of the storage test and sensory data showed that the quality of GF bread products improved in recent years; they stayed comparable with their wheat-based counterparts even during a 4-day-long storage period.

Open access

Abstract

A modified QuEChERS method using a GC-ECD to determine the multiple residues of pyraclostrobin, difenoconazole, dimethomorph and azoxystrobin and to indirectly determine the total residues of maneb, mancozeb and propineb by a GC-FPD (with an S filter) was established and validated. Meanwhile, field trials were conducted in accordance with good agricultural practice (GAP) to study their characteristics of residue degradation under the agricultural climate and cropping system of Guangxi Province. The separation effect of each target peak was good with a linearity range of 0.01–5 mg L−1, a limit of detection (LOD) of 0.003–0.015 mg kg−1 and a limit of quantification (LOQ) of 0.01–0.05 mg kg−1. The average recovery ranges of vegetable tomatoes and cherry tomatoes were 70.5–120.0% and 70.8–119.8%, respectively, with relative standard deviations (RSDs) of less than 7.1%. Field trials of seven fungicides in vegetable and cherry tomatoes showed that the half-lives (t 1/2) of the dithiocarbamate fungicides (metiram, mancozeb, and propineb, defined as total residues determined as CS2), pyraclostrobin, difenoconazole, dimethomorph, and azoxystrobin were in the ranges of 5.2, 12.7–17.8, 7.6–7.9, 6.6–6.9, and 6.3–6.6 d in vegetable tomatoes, respectively. The cherry tomatoes presented ranges of 4.3–4.5, 10.8–11.8, 6.7–7.0, 5.4–5.5, and 5.9–6.2 d, respectively. Combined with the final residue and market monitoring results, the results show that cherry tomatoes have significantly higher terminal residues, initial deposits, and maximum residues of seven fungicides than vegetable tomatoes, and these seven pesticides can be detected in cherry tomatoes purchased from three markets. Therefore, cherry tomatoes may be regarded as representative varieties of tomatoes in realizing residual extrapolation for the establishment of the maximum residue limit (MRL) value of fungicides in tomatoes and for conducting market monitoring.

Open access

Abstract

There has been a lively interest on macrocyclic polyamine alkaloids due to their remarkable pharmacological activities such as anti-tumor, anti-inflammatory, anti-Alzheimer's disease and anti-parasitic. Tripterygium wilfordii is a widely used traditional Chinese medicine, which is abundant in alkaloids including macrocyclic polyamine alkaloids. However, there are rarely studies on macrocyclic spermidine alkaloids of T. wilfordii so far. In this article, we use three known macrocyclic spermidine alkaloids celafurine, celabenzine and celacinnine, and successfully develop a simple and sensitive HPLC method for simultaneous quantification of macrocyclic spermidine alkaloids in root, stem and leaf of T. wilfordii.

Open access

Abstract

β-sitosterol (BS) and lupeol (LU) exhibit a number of biological activities and are the important bioactive marker compounds in pharmaceutical science. In the present study, a simple, precise, accurate and validated high performance thin layer chromatographic (HPTLC) method was developed for simultaneous quantification of these two compounds in leaves, stem and roots of Uraria picta, a critically endangered medicinal plant and one of the important constituents of ten plants ayurvedic formulation called Dashmoola. Standards and test samples were applied on TLC aluminum plate precoated with 0.2 mm layer of silica gel 60F254. The plate was run in a twin glass chamber comprising toluene: methanol: chloroform (8:1:1, v/v/v) as a mobile phase. The plates were immersed in anisaldehyde-sulfuric reagent and then heated at 105 °C for 5 min in CAMAG TLC plate heater for appearance of bands. Densitometric scanning was performed at λ max = 525 nm using tungsten light source in CAMAG TLC Scanner4 armed with WinCATS software. R F values of BS and LU standards and those of test samples were found to be 0.53 ± 0.01 and 0.63 ± 0.01 respectively. The method was further validated by following the International Conference of Harmonization (ICH) guidelines. For BS and LU, the linear regression data for the calibration plots revealed a satisfactory linear association with r 2 = 0.995 and 0.998, respectively. Linear range for both BS and LU was 200–600 ng/band. Accuracy of the method was evaluated by performing recovery study at three different levels by standard addition methods with an average recovery of 99.86% and 101.07%. The results revealed that the leaf samples of U. picta contained highest concentration of BS (0.150 ± 0.02%) while its root samples confined the highest concentration of LU (0.149 ± 0.01%). The developed method can be applied for routine and quality control analysis in different herbal formulations containing U. picta species.

Open access
Acta Chromatographica
Authors: Xiuhui Tian, Dianfeng Han, Yanmei Cui, Lihua Ren, Fang Jiang, Hui Huang, Xianghong Gong, Jinglin Xue, Jiawei Li, Huihui Liu, Yingjiang Xu, Xiaojun Luo, Xiaojing Liu, and Xiuzhen Zhang

Abstract

A sensitive and validated method for determining quinocetone and its main metabolites (3-methylquinoxaline-2-carboxylic acid and dedioxoquinenone) was established in aquatic products using ultra-high-performance liquid chromatography-tandem spectrometry (UHPLC-MS/MS). Samples were extracted with 2.0 mol L−1 hydrochloric acid, then purified on MAX columns. After extraction and purification, the supernatant was evaporated to dry nearly under a gentle stream of nitrogen at 40 °C. Formic acid-acetonitrile-water (0.1/30/70, v/v/v) was adjusted to 1.00 mL final volume. An aliquot (10 μL) was injected into the C18 column for separation with the mobile phase of acetonitrile and 0.5% formic acid in water at 0.25 mL min−1. Calibration curves were linear ranged from 10.00 ng mL−1 to 200.0 ng mL−1 for quinocetone and 3-methylquinoxaline-2-carboxylic acid, and 20.00 ng mL−1 to 400.0 ng mL−1 for dedioxoquinenone. Mean recoveries were 70%–89%, 73%–83% and 72%–84%, respectively. The limit of detection (LOD) was 1.00 μg kg−1, 1.00 μg kg−1 and 2.00 μg kg−1, and quantification (LOQ) were 2.00 μg kg−1, 2.00 μg kg−1 and 4.00 μg kg−1 for quinocetone, 3-methylquinoxaline-2-carboxylic acid, and dedioxoquinenone. Based on the method above, the analytes were determined in Apostichopus japonicus, three fishes (including Ctenopharyngodon idellus, Crucian carp and Oreochromis mossambicus), Penaeus vannamei, Penaeus chinensis, and Chlamys farreri. The method shows good sensitivity, linearity, precision, and accuracy. In short, the proposed method was reliable for the determination of quinocetone, 3-methylquinoxaline-2-carboxylic acid, and dedioxoquinenone in aquatic products.

Open access

Abstract

A new precise, selective and reliable reversed phase high performance liquid chromatographic (RP-HPLC) method has been developed and validated for the determination of Methyl paraben sodium (MPS) and Propyl paraben sodium (PPS) (preservatives) in Iron protein succinylate syrup. Optimized conditions were; Methanol: Water (65: 35) as mobile phase, UV/Vis detector at the wavelength of 254 nm and flow rate was set at 1.3 ml min−1. By applying the set of conditions, separation of components was carried out in less than 7 min for both the analytes. The method was validated according to International conference of Harmonization (ICH) guidelines and the analytical characteristic parameters of validation included specificity, limit of detection (LOD), limit of quantification, linearity, accuracy, precision and robustness were evaluated. The calibration curve was found to be linear in the range of 0.045 mg mL−1 to 0.075 mg mL−1 for Methyl paraben sodium and 0.015 mg mL−1 to 0.025 mg mL−1 for propyl paraben sodium with a correlation coefficient r 2 > 0.999. Accuracy; reported as percentage recovery was found to be in the range of 98.71%–101.64% for Methyl paraben sodium and 99.85%–101.47% for Propyl paraben sodium at 80%, 100% and 120% concentration for both the analytes. The proposed method was found to be precise and robust when evaluated by variations in wavelength, mobile phase composition, temperature and analyst. The limit of detection (LOD) was found 0.001 mg mL−1 (3 ppm) for Methyl paraben sodium and 0.001 mg mL−1 (1 ppm) for Propyl paraben sodium.

Open access

Abstract

Dispersive liquid-liquid microextraction (DLLME) and high performance liquid chromatography – UV detection was presented for extraction and determination of nandrolone and testosterone in human urines. Chloroform at microliter volume level and acetonitrile were used as extraction and dispersive solvents, respectively. The main advantages of method are high speed, high enrichment factor, high recovery, good repeatability and extraction solvent volume at µL level. The influence of several variables (e.g. type and volume of disperser and extraction solvents, ionic strength, etc.) on the performance of the sample preparation step was carefully evaluated. Under the optimum conditions, the calibration graphs were linear in the range of 5–500 μg L−1 with detection limit of 2.5 μg L−1 for both of them. The relative standard deviation (R.S.D.s) for five replicate measurements of nandrolone and testosterone were 9.4% and 8.8%, respectively. The relative recoveries of nandrolone and testosterone in urine sample at spiking level of 25.0 μg L−1 are ranged between 86.4% and 98%. DLLME combined with HPLC-UV is a fast, simple and efficient method for the determination of nandrolone and testosterone in human urines.

Open access

Abstract

A novel method was established for analysing trace four acidic phytohormones, namely, indole-3-acetic acid, 3-indolebutyric acid, abscisic acid, and 1-naphthylacetic acid, using magnetic ordered mesoporous carbon (MOMC). MOMC was facilely synthesised via self-assembly strategy with a direct carbonisation process. The properties of MOMC were characterised using various instruments. MOMC exhibited excellent adsorption capacity towards the analytes. Various critical parameters which may influence the enrichment efficiency were evaluated, including amount of MOMC, extraction conditions, and desorption conditions. An efficient method based on MOMC magnetic solid-phase extraction coupled with ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) was developed to analyse the trace four acidic phytohormones, with good correlation coefficients (R 2 = 0.9965–0.9998) and low limits of detection (0.13–9.7 ng L−1, S/N = 3). Trace acidic phytohormones in Agaricus bisporus and Hypsizygus marmoreus samples were determined with satisfactory recoveries (91.8–108%) and reproducibility (2.6–6.3%). The features indicated that MOMC provides an efficient platform for mushroom sampling; the developed method is convenient, promising, and sensitive for the detection of trace phytohormones in complicated mushroom samples.

Open access

Abstract

Gentamicin sulfate is a potent broad spectrum aminoglycoside antibiotic which is used against Gram-positive and Gram-negative bacteria. A simple, isocratic HPLC method for separation, identification and determination of gentamicin and parabens (methylparaben and propylparaben) was developed and validated. To our knowledge there is no report about simultaneous determination of those three analytes in pharmaceutical products. The optimum chromatographic conditions were achieved on CN column with a mobile phase consisting of 0.15% triethylamine in 10 mM KH2PO4 aqueous solution (final pH 3.0 adjusted with H3PO4) and methanol in the ratio 70:30 (v/v), providing selective quantification of analytes within 5 min. The method was successfully validated according to ICH guidelines acceptance criteria in terms of selectivity, linearity, accuracy, precision and robustness. The linearity of the method was proved in defined concentrations ranges for gentamicin (0.32–1.04 mg mL−1), methylparaben (0.0072–0.0234 mg mL−1) and propylparaben (0.0008–0.0026 mg mL−1). Relative standard deviations calculated for all analytes in precision testing were <2% (analysis repeatability) and <3% (intermediate precision). Recovery values were between 98.87% and 101.67%. Chromatographic parameters are not significantly influenced by small variations of column temperature, pH and molarity of KH2PO4. Finally, the method was successfully applied for quantitative determination of gentamicin and parabens in commercially available solution for injection. Proposed HPLC method is found to be promising in terms of simplicity, analysis times and non-use of derivatization and ion-pair agents.

Open access

Soil science, a relatively young field of research with a history of fewer than two centuries, experienced an exponential expansion in scientific output in the last decades. While the output of all sub-disciplines is growing, research efforts in these sub-disciplines differ, reflecting the importance of the subjects. The broadening focus of soil science can be detected by the content of the increasing number and diverting thematic sessions of the World Soil Science Congresses, which are held every four years since the beginning of the 20th century. The structure of the current world congress is supposed to reflect the contemporary understanding of the internal structure of soil science, including its subdivision by major themes. Considering these soil themes/sub-disciplines, we assessed the evolution of soil science in the last three decades using scientific publications as indicators. Furthermore, we evaluated the inter-linkages of soil topics within soil research using network analysis and assessed the contribution of science to the broader fields of studies, from agriculture to engineering and environmental sciences. Results show that scientific interest towards all sub-disciplines is exploding, but environment-related topics, including subjects related to climate and contamination, show an even sharper increase. As far as the internal structure of soil science is concerned, research efforts are organised around the major topics of microbiology, soil contamination, nutrients, soil physics and water management. Our study reveals that currently the highest interest towards soil is coming from ecology and environmental sciences, followed by agriculture, engineering, geology and plant sciences, respectively.

Open access

Abstract

Corticosteroids are anti-inflammatory and immunosuppressant drugs. Topical corticosteroids formulations (ointments, creams, gels) are used in the treatment of different types of dermatitis and urticaria. Considering their therapeutic and whitening effects, they are frequently used for counterfeiting of cosmetic products. Corticosteroids can cause different local and systemic side effects. HPLC method is often chosen for their analysis, because it is selective, sensitive, precise, simple and fast.

The aim of this study was optimization and validation of RP-HPLC method with UV detection for determination of trace levels of corticosteroids in ambiphilic creams. This method is used for qualitative and quantitative analysis of evaluated corticosteroids.

Mometasone furoate, hydrocortisone acetate, fluocinonide, fluocinolone acetonide, betamethasone, betamethasone dipropionate and triamcinolone acetonide were evaluated. Separation was performed on Inertsil® ODS-3V 250 × 4.6 mm, 5 μm chromatographic column. Mobile phase was mixture of acetonitrile and water 50:50 (v/v) with gradient elution and flow rate 1 mL min−1. Column temperature was held on 40 °C and UV detection was performed at 240 nm.

Selectivity, linearity, accuracy, precision and limit of quantification (LOQ) were evaluated. Method is selective because ambiphilic cream base peaks and corticosteroids peaks were not overlapping. Linearity was confirmed since correlation coefficient was 1 for all compounds. Accuracy and precision were evaluated for hydrocortisone acetate and betamethasone dipropionate. Determined Recovery values were in range of 70–130%. Both RSD values (21.46% and 9.59%) were lower than 30%. Method is highly sensitive since LOQ concentrations were in ng mL−1 range.

All evaluated parameters of validation were in accordance with regulatory requirements. Validated RP-HPLC method can be used for qualitative and quantitative analysis of selected corticosteroids in ambiphilic creams.

Open access
Progress in Agricultural Engineering Sciences
Authors: József Mihalkó, Dóra Szepesi-Bencsik, Gabriella Zsarnóczay, and László Ferenc Friedrich

Abstract

Animal food, especially meat, has played an important role in the history of mankind. Different meats can be used in the production of meat products. In addition to lean meats, mechanically deboned meat (MDM) and mechanically separated meat (MSM) can also be used in meat products. However, the latter does not qualify as meat due to damage to the muscular structure due to the high pressure applied during the separation, therefore cannot be included in the meat content of products.

The aim of our experiment was to compare whole, minced meat, MDM and MSM from turkey (raw and in the form of meat paste). Technofunctional tests (water-holding and -binding capacity), color measurement, chemical composition (moisture, protein and fat content), electron microscopic recording, rheological properties show that the quality of MSM is inferior to other meat raw materials. These properties can also result in the production of lower quality products.

Open access

Abstract

The accurate, simple, and selective reversed phase high performance liquid chromatography (RP-HPLC) has been established and validated for the determination of an antibiotic ampicillin (AMP) in human blood plasma. The SPE extraction was used for the sample preparation. Chromatographic separation was accomplished by a mobile phase containing 15 mM monopotassium phosphate solution of pH 3.3 and methanol (75:25, v/v) in an isocratic mode at a flow rate of 1.4 mL min−1 at 30 °C. The separation was evaluated on a column with a new polar-endcapped C18 stationary phase Arion® Polar C18 or well-known phase Luna® Omega Polar C18. Excellent linearity (R 2 0.9998) was shown over range 10–300 mg L−1 with mean percentage recovery 90%. Peak shapes were symmetrical in both columns, Arion® Polar C18 and Luna® Omega Polar C18, with asymmetry factor of 1.0 and 1.4, tailing factor of 1.0 and 1.2, and retention factor of 4.6 and 5.6, respectively. The Arion® Polar C18 was almost 1.4-fold more effective than Luna® Omega Polar C18 phase. The LOQ for ampicillin was achieved 10 mg L−1 for Luna® Omega Polar C18 and 5 mg L−1 for Arion® Polar C18 using 20 µL of a solution containing 0.24 mg mL−1 of cephalexin as an internal standard.

A number of articles dealing with the determination of ampicillin is limited, therefore, this study showed the HPLC method suitable for the determination of AMP in human blood plasma from patient who underwent elective cardiac surgical revascularization. In addition, the determination of AMP was also performed for the first time using an Arion® Polar C18 column, which effectively separated AMP from other compounds present in human blood plasma. This new polar-endcapped phase can help in separation of polar antibiotics or other polar compounds, which are unsuccessfully separated on conventional C18 column, and thus can help during method development.

Open access

Abstract

Gas chromatography-ion mobility spectrometry (GC-IMS) is an emerging analytical technique that has the advantages of fast response, high sensitivity, simple operation, and low cost. The combination of the fast speed and resolution of GC with the high sensitivity of IMS makes GC-IMS play an important role in the detection of food volatile substances. This paper focuses on the basic principles and future development trend, and the comparative analysis of the functions, similarities and differences of GC-IMS, GC-MS and electronic nose in the detection of common volatile compounds. A comprehensive introduction to the main application of GC-IMS in food volatile components: fingerprint identification of sample differences and detection of characteristic compounds. On the basis of perfecting the spectral library, GC-IMS will have broad development prospects in food authentication, origin identification, process optimization and product classification, especially in the analysis and identification of trace volatile food flavor substances.

Open access

Abstract

A simple, rapid, and environmentally friendly sample preparation method for pyrethroids determination in cereals using cyclodextrin-assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplets coupled with high-performance liquid chromatography was established. The cereal samples were extracted with acetonitrile, cleaned up, and concentrated by green extractant menthol via γ-cyclodextrin assisted extraction process. The extractant menthol dispersed as fine droplets in the cyclodextrin solution and then solidified at room temperature for efficient extraction and convenient collection. The optimized method provided good linearity in the range of 0.01–10 mg kg−1 with limits of detection of 3.5–9.5 μg kg−1. The fortified recoveries of three pyrethroids (i.e., lambda-cyhalothrin, deltamethrin, and bifenthrin) in four cereals (i.e., rice, wheat, maize, and millet) at three levels were in the range of 77.6–101.6% with relative standard deviations of 0.6–6.6%. Overall, the proposed method can be successfully applied for the determination of pyrethroids in cereals.

Open access

Abstract

A systematic DoE and Analytical Quality by Design (AQbD) approach was utilized for the development and validation of a novel stability indicating high-performance thin–layer chromatographic (HPTLC) method for Rivaroxaban (RBN) estimation in bulk and marketed formulation. A D-optimal design was used to screen the effect of solvents, volume of solvents, time from spotting to development and time for development to scanning. ANOVA results and Pareto chart revealed that toluene, methanol, water and saturation time had an impact on retention time. The critical method and material attributes were further screened by Box-Behnken design (BBD) to achieve optimal chromatographic condition. A stress degradation study was carried out and structure of major alkaline degradant was elaborated. According to the design space, a control strategy was used with toluene: methanol: water (6:2:2) and the saturation time was 15 min. A retention factor (RF) of 0.59 ± 0.05 was achieved for RBN using chromatographic plate precoated with silica gel at detection wavelength 282 nm with optimized conditions. The linear calibration curve was achieved in the concentration range of 200–1,200 ng/band with r 2 > 0.998 suggesting good coordination between analyte concentration and peak areas. The quadratic model was demonstrated as the best fit model and no interaction was noted between CMAs. The optimized HPTLC method was validated critically as stated in International Conference on Harmonization (ICH) Q2 (R1) guideline and implemented successfully for stress degradation study of RBN. The developed HPTLC method obtained through AQbD application was potentially able to resolve all degradants of RBN achieved through forced degradation study. The obtained results demonstrate that a scientific AQbD approach implementation in HPTLC method development and stress degradation study drastically minimizes the number of trials in experiments, ultimately time and cost of analysis could be minimized.

Open access

Abstract

Bicalutamide (BCL) has been approved for treatment of advanced prostate cancer (Pca), and vitamin D is inevitably used in combination with BCL in Pca patients for skeletal or anti-tumor strategies. Therefore, it is necessary to study the effect of vitamin D application on the pharmacokinetics of BCL.

We developed and validated a specific, sensitive and rapid UHPLC–MS/MS method to investigate the pharmacokinetic behaviours of BCL in rat plasma with and without the combined use of vitamin D. Plasma samples were extracted by protein precipitation with ether/dichloromethane (2:1 v/v), and the analytes were separated by a Kinetex Biphenyl 100A column (2.1 × 100 mm, 2.6 μm) with a mobile phase composed of 0.5 mM ammonium acetate (PH 6.5) in water (A) and acetonitrile (B) in a ratio of A:B = 35:65 (v/v). Analysis of the ions was run in the multiple reactions monitoring (MRM) mode. The linear range of BCL was 5–2000 ng mL−1. The intra- and inter-day precision were less than 14%, and the accuracy was in the range of 94.4–107.1%. The mean extraction recoveries, matrix effects and stabilities were acceptable for this method. The validated method was successfully applied to evaluate the pharmacokinetic behaviours of BCL in rat plasma. The results demonstrated that the pharmacokinetic property of BCL is significantly affected by combined use of vitamin D, which might help provide useful evidence for the clinical therapy and further pharmacokinetic study.

Open access

Abstract

Several studies on the pharmacokinetic parameters of antidementia drugs have reported that plasma concentration is linked to the drugs’ efficacy and adverse effects. At present, there is no quantitation method that is highly sensitive and can be applied to simultaneous monitoring of the pharmacokinetics of rivastigmine and its metabolites (NAP 226-90) in rat plasma. No methods fulfilling the assay validation requirements of the US Food and Drug Administration and the European Medicines Agency was also established. Therefore, this study developed a quantitative method for measuring rivastigmine and NAP 226-90 concentrations using high-performance liquid chromatography and tandem mass spectrometry, examining plasma samples after rivastigmine administration. Rat plasma samples were prepared via the protein precipitation method. The methods for measuring rivastigmine and NAP 226-90 concentrations showed good fit over wide ranges of 1–100 ng mL−1 and 0.5–50 ng mL−1, with lower limits of quantification at 1 ng mL−1 and 0.5 ng mL−1, respectively. The plasma concentrations of rivastigmine and NAP 226-90 in six healthy rats were successfully determined, demonstrating the feasibility of applying the developed method. Thus, this research has successfully developed a sensitive, selective method, to simultaneously quantify rivastigmine and NAP 226-90 concentrations in rat plasma and be applicable to a pharmacokinetic study.

Open access

Abstract

A sensitive and accurate LC-MS/MS method was developed and validated for the simultaneous quantification of rivaroxaban (RIV) and sitagliptin (SIT) in rat plasma using apixaban as internal standard (IS). An Agilent Eclipse plus C18 column (2.1 × 100 mm, 3.5 µm, Agilent) was used for chromatographic separation with isocratic elution. Multiple reaction monitoring (MRM) using positive-ion ESI mode to monitor ion transitions of m/z 436.8→144.9 for RIV, m/z 407.7→173.8 for SIT, m/z 459.8→442.8 for IS. The procedure of method validation included selectivity, linearity, precision, accuracy, matrix effect, extraction recovery and stability were conducted according to the guidelines of EMA and FDA. The results indicated that no obvious drug-drug interactions occurred might be owing to their differences in metabolic pathways.

Open access

Abstract

A rapid, simple and efficient ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method was established to simultaneous determination of shikonin, isobutyryl shikonin, β, βʹ-dimethylacryl alkanin in beagle plasma and evaluated by using esculetin as internal standard. The electrospray ionization (ESI) source was operated in negative ionization mode. Multi-reaction monitoring (MRM) was used to quantitatively analyzed shikonin m/z 287.0 → 217.9, isobutyryl shikonin m/z 357.0 → 268.9, β, βʹ-dimethylacryl alkanin m/z 370.0 → 270.1 and esculetin m/z 177.0 → 89.0, respectively. The method was validated for selectivity, linearity, lower limit of quantification, precision, accuracy, recovery, matrix effect and stability. All validation parameters met the acceptance criteria according to regulatory guidelines. This method was successfully applied for the pharmacokinetic study of shikonin, isobutyryl shikonin, β, βʹ-dimethylacryl alkanin in beagle dogs plasma after oral administration of A. euchroma extract.

Open access
Agrokémia és Talajtan
Authors: Birkás Márta, Balla István, Gyuricza Csaba, Kende Zoltán, Kovács Gergő Péter, and Percze Attila

A magyar talajművelésben a kezdetektől az 1900-as évek közepéig a hagyományos szántásos rendszerek domináltak. Az ekék tökéletesedése révén a mélyebb szántások hozzájárultak a talajminőség romlásához.

Az 1900-as évek első évtizedeiben a külföldön kidolgozott művelési módszerek még kevesek érdeklődését keltették fel, azonban a szántásnál kedvezőbb körülmények létrehozása érdemi figyelmet keltett.

Az 1970-es évektől a talajvédő művelés Magyarországon is kedvező fogadtatásra talált. Kísérletekkel igazolódott, hogy a direktvetés előnyei – folyamatosság esetén – a hatodik-hetedik évtől észlelhetők. A mulcshagyó művelés kultivátor alkalmazása esetén rövidebb idő alatt nyújtotta a várt talajvédelmi előnyöket, ennek tudható be a gyorsabb terjedése. A kultivátoros művelés értékét a felszínvédő mulcshagyás, a talajminőség megóvás és a biológiailag aktív talaj erősítette meg.

Az időjáráshoz kapcsolható szélsőségek megjelenése az 1980-as évektől újabb művelési megoldások felé fordították a figyelmet. A talajlazítás a vízbefogadás és tárolás, a mulcshagyás, valamint a növények mélyebb gyökerezése révén került a korábbinál szélesebb körű alkalmazásra. A sávos művelési rendszer a nemzetközileg bizonyított eredmények hátterével számos magyar gazdálkodónál is sikeressé vált.

A magyar talajművelés előrehaladásában a talajközpontú szemlélet kiszélesedése, a növényközpontú szemlélet felváltása révén eredményezett kedvező változásokat a talajállapot javulásában.

Tekintettel a talajok sokféleségére és a talajállapot eltéréseire, jelenleg a termőhelyhez, talajhoz adaptált művelési rendszer alkalmazása látszik eredményesnek. Az időjárási szélsőségek fokozódása általában és adott termőhelyen is rangsorba állítja a lehetséges módszereket. A korábban jónak tartott megoldások, beleértve a szántást, ugyanis már egyre kevésbé biztonságosak.

A talajkímélő művelés iránti érdeklődés közel százhúsz évre tekint vissza Magyarországon. Sajátos, de az előrehaladás és a visszatartás tényezői a talajművelésben párhuzamosan jelentek meg az eltelt évek alatt. A művelési előrehaladást visszafogó tényezők között a sok évtized óta fennálló hiedelmek voltak a leginkább hátráltatók, mivel figyelmen kívül maradt a talajvédelem, továbbá a klímaváltozással kapcsolatos veszélyek enyhítésének igénye. Az előrehaladást a talajvédelem felvállalása, a gazdálkodási színvonal emelésének esélye és a klímakár csökkentés kényszere mozdította elő. Az előrehaladást alátámasztó tényezők között legfontosabbak a talajállapot tartós javulása és a klíma eredetű károk enyhítése, továbbá a termés biztonság megtartása és javulása.

Open access

Abstract

As the world is facing numerous global ecological issues at once, the question arises of what will help mitigate and solve contemporary matters related to resource management or climate change without devastating the economies. Fortunately, the widespread application of the circular economy would help countries worldwide simultaneously ensure economic growth without significant environmental deterioration, essentially decoupling the two factors. While Hungary’s contribution to environmental problems is not significant in absolute terms, the economic sector’s circular transition could help the country decrease its impact in relative terms and pave the path for a green economy. Nevertheless, companies, especially SMEs, tend to struggle the most with the initial phases of the shift thus it is crucial to assess the factors that prevent and support their transition.

Open access

Abstract

This study establishes a method for rapid detection of clonidine and cyproheptadine in foods of animal origin. In order to obtain the best detection method, capillary zone electrophoresis (CZE), large volume sample stacking (LVSS), and sweeping-micellar electrokinetic capillary chromatography (sweeping-MEKC) were used respectively. The limits of detection (LODs) of clonidine and cyproheptadine by LVSS-CZE were 0.028 μg mL−1 and 0.034 μg mL−1, and those by sweeping-MEKC were 0.023 μg mL−1 and 0.031 μg mL−1, respectively. Compared with the CZE method, the two online pre-concentration technologies have greatly improved the detection sensitivity and achieved good enrichment results. However, compared with the sweeping-MEKC system, the LVSS system consumed a longer time and was greatly affected by the actual sample matrix. The sweeping-MEKC method was proved to be suitable for real sample analysis. Under the best sweeping-MEKC conditions, clonidine and cyproheptadine could be well separated within 8 min and good linear relationships in the range of 0.1–1.0 μg mL−1 (r 2 > 0.99) were obtained. This method was successfully applied to the determination of clonidine and cyproheptadine in animal-derived foods with the recoveries of 82.3%–90.1% and the relative standard deviations (RSDs) less than 3.11%. The sweeping-MEKC method is simple to operate and has great potential in the rapid detection of clonidine and cyproheptadine in animal-derived foods.

Open access