Browse Our Chemical Engineering Journals
Chemical engineering is an engineering branch that deals with the chemical production and manufacture of products that undergo chemical processes. This includes equipment design, creating systems and processes to refine raw material, as well as mixing, compounding, and processing chemicals to create products.
Chemistry and Chemical Engineering
The phytochemical fingerprint profile of ammoniacum gum (from Dorema ammoniacum) was defined by subjecting different extracts of the gum to qualitative and semi-quantitative analysis by high-performance thin-layer chromatography. The different compounds present in alcohol and n-hexane extracts of the gum and in its volatile oil were resolved by TLC and detected by densitometric scanning in the UV at λ = 254 and 366 nm, and by post-chromatographic derivatization. The resolved bands were evaluated for their spectral details, the relative concentrations were determined by densitometry, and band properties such as color, fluorescent or non-fluorescent nature, R F, and λmax were also recorded. Two commercial samples of ammoniacum gum were evaluated by comparison of their phytochemical fingerprint profiles with that of the genuine sample. The work has revealed the potential of this type of automated qualitative and semi-quantitative evaluation by HPTLC as an efficient tool for standardization, for testing the purity and authenticity of herbal drugs, and for quality-control purposes.
The aim of this study was to find suitable separation conditions for the rapid screening of indole derivatives in bacterial culture broths by planar chromatography with silica gel as the stationary phase. The mobile phase was optimized by the PRISMA method; thin-layer chromatography (TLC) was used in the pre-assays. Several mixtures of indole derivatives were used to achieve the necessary chromatographic separation. The combination acetic acid–ethyl acetate–toluene–n-hexane, 4 + 11 + 70 + 15 (v/v), was chosen for screening bacterial culture broths for indole-3-acetic acid (IAA) and other indole derivatives. This mobile phase was transferred, without modifications, to rotation planar chromatography (RPC) using the Extrachrom® prototype separation instrument. The results obtained by use of TLC and RPC were comparable in terms of separation efficiency, and found to be suitable for the intended purpose.
The reversed-phase thin-layer chromatographic behavior of 3d metal ions has been studied on silica gel GF254 layers impregnated with silicone fluid DC200, tri-aryl phosphate, and tri-n-butyl phosphate; mixtures of DMSO and HNO3 were used as mobile phases. The effect of silicone fluid DC200 and of the tri-aryl phosphate ion on the R F values of the metal ions is discussed. Mobile phases prepared from DMSO and 1 M HNO3 are most effective when the concentration of acid in the mixed mobile phase is between 0.10 and 0.70 M. The mechanism of migration is explained in terms of adsorption and complex formation. The effect of solvent composition on the migration behavior of the metal ions was also studied. Some binary and ternary separations were achieved.
Fumonisins were produced by six strains of Fusarium moniliforme and Fusarium proliferatum on inoculated rice culture. For study of fumonisins of the B series (B1, B2, B3, and B4) a quick and efficient two-step reversed-phase OPLC method was developed in which the first step serves for cleaning of the samples. Measurements were performed with the automatic OPLC instrument. Results showed that one isolate of F. moniliforme and one of F. proliferatum produced all the fumonisins investigated – the other isolates produced no fumonisins. This work is the first report of the separation of all the fumonisins of the B series by use of a planar layer liquid chromatographic technique.
The physicochemical properties of biogenic monoamines – their polarity, lability, and the trace amounts found in biological material – create great analytical difficulties in their identification and separation. The selective chromatographic separation of these amines is greatly facilitated by their derivatization. On the basis of theoretical assumptions 4-diisopropylaminodiazabenzene-4´-isothiocyanate (DIABITC) was synthesized and used to prepare the thiocarbamoyl derivatives of the amines. The colored derivatives were separated by TLC.
Quinolones, because of their hydrophilic (amphiionic) character, are strongly adsorbed by silica even from polar solvents. It has been shown that they can be chromatographed on thin layers of Diol-silica adsorbent by using solutions of di(2-ethylhexyl)ortho-phosphoric acid (HDEHP, an ion-pairing reagent) in polar solvents as mobile phases. Retention and selectivity in the adsorption–ion-association system can be controlled by adjusting the concentration of HDEHP (typically 5–10%, v/v) and changing the polar diluent. Both chromatograms and densitograms are presented.
Eighteen new agents have been used for visualizing eight esters of higher fatty acids after chromatography on silica gel, on a mixture of silica gel and kieselguhr, and on neutral aluminum oxide. Limits of detection (detectability, D), detectability index, and broadening index were determined for the esters investigated after use of the visualizing agents. For all the esters investigated the best detectability was obtained on the mixture of silica gel 60 and kieselguhr F254; it was worse on silica gel 60 F254 and worst on neutral aluminum oxide. Bromophenol blue was the best and most universal visualizing agent for all the esters investigated on all the chromatographic supports.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
“Talaj – növény holobiont komplex – a megismeréstől az alkalmazásig”•
tudományos előadóülés (on-line), 2021. szeptember 16.
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.
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.
Abstract
Potential functional food bakery products were developed and characterized based on White Lupin (Lupinus albus cv. Nelly) flour. Analytical properties of the seeds resemble to previously described Lupinus species, with significantly high protein content (45%). The high protein and dietetic fiber content of the seeds makes Lupin flour suitable to develop potential functional food products with high nutritional values. Results of the development of sweet biscuits and salty crackers enriched with Lupin flour are presented. Sensory evaluation of the bakery products was carried out by 15 panelists using the nine points hedonic scale. Heat stability of White Lupin proteins were investigated by gel-electrophoretic analysis, White Lupin proteins are quite stable at 140°C, after 35 min heating the biscuits still contain 69% of the original amount of proteins. Baking conditions were optimized also based on gel-electrophoretic experiments, the optimal baking time was 30 min at 140°C. Gluten-free Lupin-based biscuits and crackers were produced by completely omitting wheat flour from the recipes.
Abstract
Wastewater issues became a complex challenge in the world. There are several methods in wastewater treatment, such as chemical, physical, biological, and the combination of each method. However, each process has advantages and disadvantages. The physicochemical methods are common methods used in wastewater treatment, such as adsorption and coagulation. Adsorption and coagulation are excellent methods to remove pollutants. The adsorption process is greatly influenced by pH, adsorbent dose, temperature, and contact time. Coagulant dose, settling time, and pH are the main factors in the coagulation process. Chemical material as an adsorbent and coagulant has been studied in previous research, but recently, to substitution chemical materials is a challenging subject. Natural substances are potential new materials in wastewater treatment and became popular due to their efficiency and environment friendly characteristics. This review investigated the role of adsorption and coagulation in wastewater treatment and the utilization of natural materials as adsorbents and coagulants.
Abstract
Built elements and structures are a prominent component of our historic gardens, both in terms of function and artistic composition and garden scenery. The surveys of historic garden structures are important research tasks, which also underpins and validates restoration work.
In most cases, the neglected state of historic gardens and sites and the unavailable archival materials do not allow an authentic restoration of historic gardens to their original state. Nevertheless, there is a real need to reconstruct our historic gardens, based not only on historical authenticity but also on a systematic reinterpretation of the relationship between society and landscape.
The objective of this article is to present a general methodology for renewal of historic gardens through examples of specific garden reconstructions. The case studies are the authors' own design works, which demonstrate the application of different design approaches, highlighting details of the reconstruction of specific built garden elements.
Abstract
A sensitive and reliable method for simultaneous determination of oryzalin and ethofumesate residues in pantnagar soil and water was validated. The compounds were extracted by LLE with dichloromethane from water, and acetone:methanol mixture from soil followed by SPE cleanup. Detection and quantification was done by RP-HPLC using mobile phase methanol:water (70:30, v/v) at 280 nm. The developed method showed satisfactory validation results with linearity (0.99), relative standard deviations (1.55 and 1.73%), and limit of quantification (0.002 μg g−1 and 0.005 μg g−1) for ethofumesate and oryzalin, respectively. Recoveries ranged for oryzalin and ethofumesate from 79.80–90.52, 75.58–86.04% (soil) and 83.50–95.92, 82.28–94.60% (water), respectively. The method could be used for routine high-throughput detection and determination of these compounds.
Abstract
Sulfacetamide sodium is a widely prescribed sulfonamide drug due to its topical antibacterial action on eye and skin. Four impurities are stated in the British Pharmacopoeia among which are sulfanilamide and dapsone. This work presents two specific, accurate and precise chromatographic methods for the simultaneous determination of a mixture of sulfacetamide sodium, sulfanilamide and dapsone. The first method is an isocratic RP-HPLC where the separation of components was achieved on C18 column. A green mobile phase was used consisting of methanol:water (60:40, v/v). The flow rate was 1.0 mL/min and effluent was monitored at 273 nm. The second method is a TLC-spectrodensitometric one where good separation was achieved by using silica plates and a mobile phase consisting of chloroform:dichloromethane:acetic acid (6:2.5:1.5, by volume). Determination was done by densitometry in the absorbance mode at 273 nm. Both methods were validated in compliance with ICH guidelines. They were also successfully applied for the determination of sulfacetamide sodium and its impurities in Ocusol® ophthalmic solutions. The obtained results were statistically compared to the results obtained by applying the official methods of analysis of each component where no significant difference was found with respect to accuracy and precision.
Abstract
In this study, a UPLC-MS/MS method was developed to measure the concentrations of the flavonoids oroxin A, oroxin B, oroxylin A, oroxyloside, chrysin, chrysin 7-O-beta-gentiobioside, and guaijaverin in the blank mouse blood, and the method was then used in the measurement of the pharmacokinetics of the compounds in mice. Oroxin A, oroxin B, oroxylin A, oroxyloside, chrysin, chrysin 7-O-beta-gentiobioside, and guaijaverin were administered intravenously at a dose of 5 mg kg−1, and the mouse blood (20 μL) was withdrawn from the caudal vein 0.08333, 0.25, 0.5, 1, 2, 4, 6, 8, and 10 h after administration. The mobile phase used for chromatographic separation by gradient elution was composed of acetonitrile and water (0.1% formic acid). The analytes were detected by operating in electrospray ionization (ESI) positive-ion mode using multiple reactions monitoring (MRM). The intra-day and inter-day accuracy ranged from 86.2 to 109.3%, the intra-day precision was less than 14%, and the inter-day precision was less than 15%. The matrix effect ranged from 85.3 to 111.3%, and the recovery of the analytes after protein precipitation were all above 78.2%. This method had the advantages of high sensitivity, accuracy, and recovery, and it had excellent selectivity, which enabled it to be applied to measuring the pharmacokinetics of the analytes in mice.
Abstract
A reliable LC-MS/MS method for the determination of five bioactive constituents (bilobalide, BLL; ginkgolide A, GLA; ginkgolide B, GLB; ginkgolide C, GLC; rutin) of Ginkgo biloba leaf extracts (GBE) in rat plasma was established, fully validated and applied to an intragastric pharmacokinetic study of a preparation of GBE in rat. Samples were extracted with ethyl acetate. C18 column was selected as analytical column in this method. Mobile phase was water with 0.01% formic acid and acetonitrile. Quantification was performed in negative multiple-reaction monitoring mode. Matrix instability of terpene lactones was noticed and hydrochloric acid was used as a stabilizer. This method showed good precision and accuracy, recovery was reproducible and matrix effect was negligible. Among four terpene lactones, BLL had the highest exposure and the shortest terminal half-life, GLA and GLB had lower exposure and longer terminal half-life, the exposure of GLC was lowest and its terminal half-life was the maximum, and all of them showed rapid absorption. This study provides a reference for determination of terpene lactones and flavonol glycoside prototypes in GBE and offers pharmacokinetic data of flavonol glycoside prototype in GBE.
Abstract
A validated UHPLC-PDA with an ESI-MS/MS method has been developed for simultaneous estimation of six bioactive alkaloids (magnoflorine, berbamine, columbamine, jatrorrhizine, palmatine and berberine) in the different extracts of the roots of Berberis aristata DC (Family:Berberdiaceae). It is an important medicinal herb native to Northern Himalaya and commonly known as ‘daruharidra’, ‘daruhaldi’, ‘Indian barberry’ or ‘tree turmeric’. An insight into the research literature uncovered reports on isoquinoline alkaloids like magnoflorine, berbamine, columbamine, jatrorrhizine, palmatine, and berberine as major bioactives in B. aristata roots, possessing different pharmacological and therapeutic effects. In the present study, these aforementioned alkaloids were separated on Phenomenex Luna®, 5 µm-C8 analytical column. The HPLC-MS analysis was performed at a flow rate of 0.90 mL min−1. Each alkaloid that is resolved was characterized by precursor ions and fragment ions with electrospray ionization (ESI) source in both positive and negative ionization using scan mode. The limit of detections (LODs) were 0.087, 0.727, 0.035, 0.124, 0.782 and 0.794 μg mL−1 for magnoflorine, berbamine, columbamine, jatrorrhizine, palmatine and berberine, respectively. The proposed UHPLC-PDA method was fully validated according to international (ICH) guidelines and was found to be selective, sensitive and highly accurate for the concomitant estimation of the aforementioned symbolic bio-markers of B. aristata roots.
Abstract
The current study explores a design and development of the simple, fast, green and selective novel method of UPLC to quantify pitavastatin and ezetimibe simultaneously. The combined approach of Green Analytical Method with Quality by Design-based risk assessment was done using the Ishikawa fishbone diagram followed by a rotatable central composite design used for the optimization. The optimal chromatographic separation was attained through a mobile phase of 72: 28% v/v ethanol and 0.1% orthophosphoric acid (pH 3.5), with a 0.31 mL min−1 flow rate. The developed UPLC-PDA method was sensitive and specific for pitavastatin and ezetimibe, with linearity ranging from 2 to 30, 10–150 μg mL−1 with an R2 of 0.9999 and 0.9997, respectively. The forced degradation study of stability-indicating assay results shows the degradation in respective stress conditions. The developed UPLC method was validated and found to have sensible results with good linearity, accuracy and precision. Further, the greenness was evaluated using five states of art metrics like NEMI, GAPI, AES, AMGS, and AGREE metrics and found the greenest results. Based on the results we concluded that the developed UPLC method could be efficient for the simultaneous determination of pitavastatin and ezetimibe in bulk and tablet dosage.
Szélerózió okozta talaj-, humusz- és tápanyag-áthalmozás különbségeinek feltárása különböző szerkezeti adottságú csernozjom talajokon terepi szélcsatorna kísérletek alapján
Exploring the differences in soil, humus and nutrient accumulation caused by wind erosion on chernozem soils with different structural properties by field wind tunnel experiments
Kutatásunk során Magyarország két dél-alföldi réti csernozjom talajú területét vizsgáltuk azon céllal, hogy in situ körülmények között számszerűsítsük a különböző szélesemények által okozott talajveszteség mértékét, az ezzel együtt járó humusz- és tápanyagáthalmozás nagyságrendjét, valamint a két terület defláció érzékenységében tapasztalt különbségek okait.
Vizsgálati területeink Békés megyében, Makótól K-re mintegy 10 km-re, Apátfalva külterületén, valamint Csongrád megyében Szegedtől ÉNy-ra 2 km-re helyezkedtek el. Kutatásunk célkitűzései az alábbiak voltak: terepi szélcsatornás mérésekre alapozott laboratóriumi mérések alapján különböző szerkezeti állapotú csernozjom talajokra meghatározni
- ◾ az indítósebességet,
- ◾ a szélerózióval áthalmozott szedimentben mért makroelem, és humuszanyag feldúsulását,
- ◾ valamint az ezekre ható talajtani tényezőket.
A hasonló mechanikai összetételű, Szeged és Apátfalva melletti réti csernozjom talajok aggregátum összetételében, valamint a CaCO3 és humusztartalomban megfigyelhető különbségek hatására a Szeged melletti csernozjom mintaterület talaja defláció érzékenyebb. A Szegedtől É-ra eső csernozjomokon 6,5–9,0 m s–1 közötti indítósebesség értékeket mértünk, míg Apátfalván 13,0 m s–1 volt az indítósebesség értéke. Az apátfalvi terület talajának magasabb karbonát- és humusztartalma, valamint aggregátum összetételében mért magasabb morzsa arány az indítósebességérték növelésének irányába hat. A feltalajban a 0,5 mm-nél kisebb aggregátumok magasabb aránya következtében nemcsak kisebb indítósebesség értékeket, hanem nagyobb áthalmozódó talajmennyiséget, valamint ezzel együtt nagyobb mennyiségű humusz- és foszfor elmozdulást mértünk az egységesen 10-10 perces fújatási kísérleteink alkalmával a szegedi mintaterületen. Megállapítható tehát, hogy egyazon talajtípusba eső, s azonos textúrájú (homokos vályog) talajok esetében az aggregátum összetételben, valamint a CaCO3 és humusztartalomban megfigyelhető eltérések hatására jelentős különbségek tapasztalhatók a defláció érzékenység, az indítósebesség, a szediment szállítás módja és a humusz- és elemáthalmozás mértéke között.
In our research, two Chernozem soil areas were examined in the southern part of the Great Hungarian Plain in order to quantify the amount of the soil loss, humus and nutrient transport caused by different wind events and in order to show the causes of the differences in the sensitivity of deflation between the two areas.
Our study areas were located in Békés County, one of them was near Apátfalva, about 10 km east of Makó, and the other one was 2 km northeast of Szeged in Csongrád County. Our in situ wind tunnel experiments were accomplished on 2–4 June 2011 at Apátfalva and in July 2013 in Szeged. The objectives of our research were the followings:
- ◾ determination of the enrichment ratios for humus, macro- and microelements in the wind eroded sediments in the case of Chernozem soils with different structures based on field experiments and laboratory measurements;
- ◾ determination the affecting actual soil factors;
- ◾ estimation of soil loss and element rearrangement trends on Chernozem arable lands under different wind velocity on plot scale.
Because of the differences in the aggregate size distribution, CaCO3 and humus content, Chernozem soil near Szeged is more sensitive to deflation than near Apátfalva. Threshold friction velocity was measured between 6.5 and 9.0 m s–1 near Szeged, while the same parameter was 13.0 m s–1 at Apátfalva. The higher carbonate and humus content and the higher crumb ratio of the soil on the Apátfalva area result increasing threshold friction velocity. Due to the higher proportion of aggregates smaller than 0.5 mm in the topsoil, we have measured not only lower threshold friction velocities, but also a larger quantity of transported soil and a larger humus and phosphorus loss during the uniform 10-10 minute long wind tunnel experiments in the Szeged sample area. It can be concluded that even in spite of the same soil type and same texture there are significant differences between deflation sensitivity, threshold friction velocity, sediment transport mode, humus and nutrient transportation because of the significant differences in aggregate size distribution, CaCO3 and humus content.
It means that the agronomic structure of the soils greatly influences the mitigation and aggravation of the soil the stress effects caused by climate change. Extreme weather situations have drawn attention to the fact that improperly applied cultivation methods, tools, and overuse of Chernozem soils can modify the soil structure. One of the most serious affect is the dusting of the surface layer of the soil. During this process the larger macroaggregates disintegrate into microaggregates and the resulting smaller fractions are more exposed to wind erosion.
The dust load affecting our settlements is mainly originated from arable lands. The mitigation of this emission is fundamentally based on the regulation of land use, farming practices and deflation. “Best Management Practices” (BMPs) mean a group of selected tools that can reduce or eliminate the transport of pollutants from diffuse sources before, during and/or after agricultural activities. However, these diffuse agricultural loads caused by wind erosion can only be quantified if the magnitude and spatial movement of the dust and pollutants is monitored.
Abstract
Anisodus tanguticus (Maxim.) Pascher is an important Tibetan folk medicine and the source of tropane alkaloids (TAs) grown in Qinghai-Tibet Plateau. There are marked differences in quality of A. tanguticus from geographic areas. The aim of present research was to establish a method for the quantitative analysis of TAs coupled with chemometrics analysis to trace geographical origins. Qualitative analysis of TAs in A. tanguticus was carried out using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and quantitative analysis of TAs in different plant organs from different geographical origin was achieved. Contents of TAs were subjected to the principal component analysis, and orthogonal partial least-squares discriminant analysis. The contents of the three marker compounds (anisodamine, anisodine and atropine) in the roots and acrial parts of A. tanguticus were positive correlated and varied significantly from different geographical origins. Principal component analysis, and orthogonal partial least-squares discriminant analysis results showed excellent discrimination between different geographical origin of A. tanguticus. This study could provide comprehensive evaluation and further utilization of A. tanguticus resources.
Abstract
Due to the wide applicability of separation techniques that rely on the property of differential migration in pharmaceutical formulations analysis, different analytical strategies have been proposed to resolve mixtures of multi-components pharmaceuticals. Three separation methods were developed and validated for the simultaneous determination of Paracetamol (PAR), Pseudoephedrine HCl (PSE) and Chlorpheniramine maleate (CHP). The first method is a thin-layer chromatographic (TLC) separation, followed by densitometric measurement. The separation was carried out on aluminium sheet of silica gel 60 F254 using ethanol:chloroform:ammonia (1:7:0.4, by volume) as the mobile phase. Determination of PAR, PSE and CHP was successfully applied over the concentration ranges of 3–25 µg/band, 0.5–10 µg/band and 0.1–6 µg/band, respectively. The second method is HPLC separation that was achieved on C18 column using the mobile phase acetonitrile:phosphate buffer pH 5 (10:90, v/v) at a flow rate 1 mL min−1. PAR, PSE and CHP were determined by HPLC in concentration ranges of 5–400 μg mL−1, 2–40 μg mL−1 and 0.5–16 μg mL−1, respectively. The third method is a capillary electrophoresis (CE) separation. The electrophoretic separation was achieved using 20 mM phosphate buffer (pH 6.5) at 20 kV. The linearity was reached over concentration ranges of 30–250 μg mL−1, 5–50 μg mL−1 and 0.8–20 μg mL−1 for PAR, PSE and CHP, respectively. The developed methods were validated with respect to linearity, precision, accuracy and system suitability. The proposed methods were successfully applied for bulk powder and dosage form analysis with RSD of precision <2%. Moreover, statistical comparison with the official methods confirms the methods' validity.
