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Development of reverse-phase high-performance liquid chromatography method for simultaneous determination of sodium benzoate and potassium sorbate in beverages

Petanovska-Ilievska B., Velkoska-Markovska L., Jankulovska M.

Acta Chromatographica

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2017

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Vol. 29, no. 3

345--358

EN

Reverse-phase high-performance liquid chromatography (RP-HPLC) method for simultaneous determination of sodium benzoate and potassium sorbate in beverages was developed using high speed column. The simple and rapid reverse-phase method for quantitative determination of both preservatives was established on LiChroCART® Purospher STAR RP-18e (30 mm × 4 mm; 3 μm) column, mobile phase consisted of acetonitrile-phosphate buffer (pH = 3.5) in volume ratio of 8:92 (v/v), flow rate of 1 mL min−1, ultraviolet (UV) detection at 195 nm for sodium benzoate and 260 nm for potassium sorbate, and constant column temperature at 25 °C. Linearity, precision, accuracy, limit of quantification (LOQ), and limit of detection (LOD) were tested for method validation. Linearity range for sodium benzoate was 6.04–200.27 mg L−1 (R2 = 0.999) while, for potassium benzoate (R2 = 0.999), 12.19–406.36 mg L−1. The RSD values ≤1.03% demonstrate excellent intra-day precision. LOD for sodium benzoate and potassium sorbate was 0.004 and 0.003 mg L−1, while LOQ was 0.012 and 0.009 mg L−1, respectively. This method was applied for quantitative determination of investigated preservatives in beverages which were taken from Macedonian markets.

2

HPLC analysis and detection of l-deprenyl

Csomor V., Laufer R., Pöstényi Z., Kalász H., Adeghate E., Nurulain S. M., Tekes K., Adem A.

Acta Chromatographica

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2014

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Vol. 26, no. 4

649--656

EN

l-Deprenyl and its major metabolites were subjected to reversed-phase high-performance liquid chromatography (HPLC). The separation was monitored using both ultraviolet (UV) and electrochemical detectors. Ultraviolet absorbance detected l-deprenyl, l-nordeprenyl, l-methamphetamine, and l-amphetamine. Amperometric detection was specific and sensitive to the parent compound (l-deprenyl, a tertiary amine) only. Peaks of the major L-deprenyl metabolites did not give any comparable signal using amperometric monitoring.

3

Development and validation of a reversed-phase liquid chromatography method for the quantification of meloxicam in liposomes

Montejo C., Civera C., Barcia E., Negro S., Fernández-Carballido A.

Acta Chromatographica

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2013

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Vol. 25, no. 4

639--653

EN

In the present study, we have developed and validated an analytical method for the determination of meloxicam in liposomes using high-performance liquid chromatography-ultraviolet (HPLC-UV). Chromatographic separation was carried out on an Ascentis RP amide C16 column selecting a mobile phase composed of acetonitrile-0.3% formic acid solution (40:60, v/v) adjusted at pH 2.8. The mobile phase flow rate selected was 0.5 mL min -1 and UV detection at 355 nm. Piroxicam was chosen as internal standard. All the analyses were performed at temperatures of 40.0 ± 0.5°C. The calibration curve was linear over the range 18–420 ng mL -1. Relative standard deviation (RSD) for precision was <1.03%. Accuracy ranged between 98.53% and 101.41% with RSD lower than 1.5%. LOD and LOQ were 5 ng mL -1 and 15 ng mL -1, respectively. The method was simple, rapid, and easy to apply, making it very suitable for routine analysis of meloxicam in liposomes. The method could also be used with reliability for the determination of meloxicam in other pharmaceutical dosage forms.

4

Badanie promieniowania ultrafioletowego generowanego przez wyładowania niezupełne powierzchniowe w powietrzu

Frącz P.

Pomiary Automatyka Robotyka

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2010

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R. 14, nr 12

90-92

PL

W artykule przedstawiono wyniki pomiarów intensywności względnej promieniowania ultrafioletowego (UV) zmierzone dla modelu izolatora szklanego umieszczonego w powietrzu. Promieniowanie generowane było przez wyładowania niezupełne. Badano wpływ wartości napięcia generacji wyładowań na intensywność emitowanego promieniowania optycznego. Ponadto analizowano wpływ odległości czujnika pomiarowego od elektrody, do której przyłożono wysokie napięcie.

EN

The article presents measurement results of ultraviolet relative radiation intensity measured for a model glass insulator placed in the air. The radiation was generated by partial discharges. The effect of voltage on intensity-discharge generation of optical radiation is emitted. Furthermore, the influence of the distance from the electrode sensor, to which high voltage was applied on the measurement results.

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Direct Liquid Chromatography with Photodiode and Fluorescence Detection for Simultaneous Quantification of Gonadotropin-Releasing Hormone (GnRH), Its Complex with Cu2+, and Catabolites

Michaluk A., Gajewska A., Kulon K., Kozłowski H., Kochman K., Kowalczyk J., Czauderna M.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 3

383-390

EN

Gonadotropin-releasing hormone (GnRH) and its complex with Cu2+(Cu-GnRH) were separated on a Nova Pak C18 column (4 m, 150 3.9 mm I.D., Wa ters). Analyses of underivatized GnRH and Cu-GnRH were per formed by a gradient elution program (HPLC method I), UV detection at 280 nm and fluorescence detection (gammexcitation = 280 nm/gammaemis sion = 360 nm). The mobile phases used were: acetonitrile with 0.08% trichloroacetic acid (w/w) and water with 0.1% trichloroacetic acid (w/w). Elutions were carried out in a binary gradient mode with a flow-rate of 1 mL/min and column temperature of 28°C. The proposed gradient elution program with UV and fluorescence detection allowed satisfactory fraction ation of GnRH (at 31.5 plus minus 0.2 min) from Cu-GnRH (at 30.3 plus-minus 0.2 min) and endogenous species present in samples of cytosol and subcellular organelles from the hypothalamus. The proposed reversed-phase HPLC method I with fluorescence detection provides a more sensitive analytical tool for routine and simultaneous quantification of GnRH, Cu-GnRH and their enzymatic degradation products (catabolites) in all biological samples as compared with HPLC method I with UV detection. To avoid problems due to overlap ping peaks corresponding to GnRH, Cu-GnRH, and the respective enzymatic degradation products in samples of cytosol and subcellular organelles from the hypothalamus, we propose a very shallow binary gradient elution program (method I). The separation efficiency of GnRH and Cu-GnRH peaks in standards and biological samples was assessed based on purity analysis of UV spectra (250-300 nm) and on the values of ratios of the fluorescence response to UV response at 280 nm. Our second reversed-phase liquid chromatographic method (HPLC method II) with pre-column derivatization of aminoacids in catabolites of GnRH and Cu-GnRH enabled investigations of the degradation pattern as well as of the yield of enzymatic degradation of GnRH and its Complex with Cu2+ in pituitary cytosol and sub-cellular organelles.

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HPLC monitoring of the microsomal stability of rutin and quercetin

Szőke É, Petroianu G., Tekes K., Benkő B, Szegi P., Laufer R., Veress G

Acta Chromatographica

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2009

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Vol. 21, no. 3

399--410

EN

Reversed-phase HPLC has been used to monitor the concentration of the two major Chamomile components rutin and quercetin during rat liver microsomal treatment. The possibility of microsomal oxidative metabolism or stability of these two components was examined using a guard-column without any clean-up. The concentration of quercetin decreased when exposed to rat liver microsomal media whereas the rutin concentration did not change significantly over one hour of treatment.

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Determination of metamitron residues in sugar beet plants and soil applying solid-supported liquid-liquid extraction followed by gradient RP-HPLC

Drożdżyński D., Folkman W.

Chemia Analityczna

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2006

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Vol. 51, No. 3

439-446

EN

Metamitron {4-amino-3-methyl-6-phenyI-l,2,4-triazin-5(4H)-one} is a triazinone herbicide widely used for weed control in sugar and fodder beet plantations. Its residues were found to be relatively stable not only in plants but also in soil, and have to be determined in these materials. In this paper a rapid, simple and inexpensive method for determination of metamitron residues in sugar beets and soil samples has been proposed. Detection limit of 20 μg kg-1-1 was 93% and 87% for the soil and sugar beet, respectively while relative standard deviations ranged from 4.0% for the soil to 3.7% in case of the plant material.

PL

Metamitron {4-amino-6-fenylo-3-metylo-l,2,4-triazyn-5(4H)-on} należy do grupy herbicydów triazynonowych często stosowanych w ochronie upraw buraka cukrowego oraz pastewnego. Jego pozostałości, ze względu na sposób aplikacji w praktyce rolniczej, powinny być oznaczane nie tylko w materiale roślinnym ale i w glebie. Przedstawiona metoda analityczna pozwala na nieskomplikowaną, szybką i niedrogą analizę pozostałości metamitronu zarówno w próbkach buraka jak i w próbkach gleby na poziomie 20 ug kg-1 z bardzo dobrymi parametrami statystycznymi. Podstawą tej metody jest ekstrakcja metamitronu z próbek, materiału roślinnego i gleby za po mocą mieszaniny metanoi-woda (95:5). a następnie po odparowaniu matanolu, oczyszczanie ekstraktu wodnego na kolumnie SLE (solid supported liquid-liquid extraction). Ostatnim etapem procedury analitycznej jest oznaczanie herbicydu z wykorzystaniem wysokosprawnej chromatografii cieczowej w odwróconym układzie faz z detektorem UV. Średni odzysk metamitronu z próbek wzbogaconych dodatkiem standardu analitycznego na poziomie 0,1 mg kg-1 wynosił odpowiednio 93% oraz 87% dlapróbek gleby i buraka cukrowego; względne odchylenie standardowe obliczone dla odzysku wynosiło 4,0% w przypadku próbek gleby oraz 3.7% w przypadku materiału roślinnego.