Determinations of residual furazolidone and its metabolite, 3-amino-2-oxazolidinone (AOZ), in fish feeds by HPLC-UV and LC-MS/MS, respectively

The antibacterial drug furazolidone belonging to the group of nitrofuran antibacterial agents has been widely used as an antibacterial and antiprotozoal feed additive for poultry, cattle, and farmed fish in China. During application a large proportion of the administered drug may reach the environment directly or via feces. Although the use of furazolidone is prohibited in numerous countries, there are indications of its illegal use. It is known that furazolidone can be rapidly metabolized to 3-amino-2-oxazolidinone (AOZ) in the body of the target organism. In this study, a total of 21 fish feed samples, including 17 commercial fish feeds from local markets in China (representing 15 different formulations) and 4 fish feeds obtained from Germany and Turkey, respectively, are analyzed to determine whether the drug is still illegally used or commercially available feeds are contaminated by this drug. High-performance liquid chromatography (HPLC) and liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) methods have been implemented to determine furazolidone and its metabolite AOZ in fish feeds containing animal protein, respectively. An efficient and convenient cleanup method for the determination of furazolidone in fish feeds is developed, and a simple cleanup method for the determination of AOZ is used. Method recoveries for samples used were determined as 87.7-98.3% for furazolidone at two spike levels of 2.0 and 5.0 ng g(-1) and as 95.6-102.8% for AOZ at spike levels of 0.4 and 0.8 ng g(-1). Limits of detections were 0.4 ng g(-1) for furazolidone and 0.05 ng g(-1) for AOZ. The established methods are therefore suitable for the determination of furazolidone and its metabolite AOZ in fish feeds at trace contamination levels. Using the established methods, all fish feed samples have been proved to be furazolidone negative; however, AOZ is tested in 16 of 17 fish feeds obtained from local markets in the Hubei province of China, with a positive rate as high as 94.1%.

刺五加叶的HPLC-UV和ESI-MS指纹图谱研究

对12批不同来源的刺五加叶提取物进行指纹图谱研究,并利用ESI-MS指纹图谱鉴别刺五加叶与山楂叶。分别采用高效液相色谱(HPLC-UV)和电喷雾电离质谱(ESI-MS)测定12批不同来源的刺五加叶提取物,利用ESI-MS技术测定刺五加叶与山楂叶提取物,得到了分离度、精密度和重现性均较好的刺五加叶HPLC-UV及ESI-MS指纹图谱;同时,利用刺五加叶与山楂叶ESI-MS指纹图谱的差异,成功鉴别了二者,可为刺五加叶药材的质量控制提供参考。

ESI-MS和HPLC-UV法研究大黄、黄柏、赤芍炮制前后化学成分变化

目的:考察大黄、黄柏、赤芍炮制前后化学成分在质和量方面的变化,以探讨中药的炮制机理。方法:利用电喷雾质谱法(ESI-MS)和高效液相色谱法(HPLC-UV),对大黄、黄柏、赤芍炮制前后的化学成分进行详细研究。质谱:电喷雾电离源(ESI),加热毛细管温度为200℃,喷雾电压为4.5kV;液相色谱:色谱柱为Agilent Zorbax C18柱(4.6mm×150mm,5μm),柱温均为28℃。结果:大黄经酒制和醋制后,其化学成分的含量变化较大;黄柏经酒制后巴马汀的含量略有增加,而小檗碱的含量呈下降趋势;盐制对于黄柏的化学成分几乎无影响;赤芍经酒制和炒制后,芍药苷的含量都呈下降趋势。结论:不同炮制方法对化学成分的影响不同,为进一步阐明中药材炮制入药的科学内涵提供了实验依据。

野生与栽培药材麻花秦艽的HPLC／UV指纹图谱研究

采用反相高效液相色谱一二极管阵列的检测方法，分析了不同产地11批麻花秦艽药材，建立麻花秦艽药材的指纹图谱，进行野生药材与栽培药材的对比研究。结果表明：最佳条件可较全面的反映麻花秦艽药材的主要成分，栽培药材与野生药材相似度较好。

Identification of phenolics and nucleoside derivatives in Gastrodia elata by HPLC-UV-MS

An HPLC-UV-MS method for simultaneous identification of predominant phenolics and minor nucleoside derivatives in Gastrodia elata was developed, which was based on their UV and MS characteristics summarized through a series of homemade reference standard experiments. Phenolics showed characteristic UV lambda(max) at 267 nm, [M + NH4](+) base peak in positive mode and [M - H](-) base peak in negative mode while nucleosides exhibited UV lambda(max) at 255 nm, [M + H](+), [M - H + 2H(2)O](-) or [M - H + CH3COOH](-). Phenolics conjugates mainly underwent the consecutive loss of gastrodin residue (- 268 U) and the combined loss of H2O and CO2 from the citric acid unit under negative MS/MS conditions whereas nucleosides simply lost the ribose (- 132 U) under positive MS/MS conditions. According to these characteristics, a special pattern under MS/MS conditions and reported compound data for G. elata in the literature, not only 15 phenolics were identified but also 6 nucleoside derivatives were identified. Among these compounds, seven phenolics and three nucleoside derivatives have not been reported yet from G. elata.

Determination of diclofenac from paediatric urine samples by stir bar sorptive extraction (SBSE)-HPLC-UV technique

A novel stir bar sorptive extraction (SBSE) method coupled with high performance liquid chromatography (HPLC) and UV detection for the extraction of diclofenac (DIC) from paediatric urine samples has been developed and validated. Selectivity and sensitivity being the prime objectives of the bioanalytical method for clinical samples, an optimised SBSE protocol was developed that selectively extracted DIC from various concurrently administered drugs. The validated assay was found to be linear (r=0.9999) over a concentration range of 100-2000 ng mL(-1). SBSE showed consistent recoveries (similar to 70%) of DIC across the validated linearity range. Overall, the method exhibited excellent accuracy and precision across all QC concentrations, tested over three days. Calculated LOD and LOQ were found to be 12.03 ng mL(-1) and 36.37 ng mL(-1), respectively, however, for the experimental purposes, 100 ngmL(-1) was considered as the validated LOQ(accuracy and precision at this LQC was

Depletion of four nitrofuran antibiotics and their tissue-bound metabolites in porcine tissues and determination using LC-MS/MS and HPLC-UV

Depletion of the nitrofuran antibiotics furazolidone, furaltadone, nitrofurantoin and nitrofurazone and their tissue-bound metabolites AOZ, AMOZ, AHD and SEM from pig muscle, liver and kidney tissues is described. Groups of pigs were given feed medicated with one of the nitrofuran drugs at a therapeutic concentration (400 mg kg(-1)) for ten days. Animals were slaughtered at intervals and tissue samples collected for analysis for six weeks following withdrawal of medicated feed. These samples were analysed both for parent nitrofurans (using LC-MS/MS and HPLC-UV), and for tissue-bound metabolites (using LC-MS/MS). The parent drugs were detectable only sporadically and only in pigs subjected to no withdrawal period whatsoever. This confirms the instability of the four major nitrofuran antibiotics in edible tissues. In contrast, the metabolites accumulated to high concentrations in tissues (ppm levels) and had depletion half lives of between 5.5 and 15.5 days. The metabolites of all four drugs were still readily detectable in tissues six weeks after cessation of treatment. This emphasizes the benefits of monitoring for the stable metabolites of the nitrofurans.

Quantification of isoorientin and total flavonoids in Passiflora edulis fruit pulp by HPLC-UV/DAD

A method is reported for the quantification of isoorientin (using a standard addition method) and total flavonoids (expressed as rutin, using the external standard method) in passion fruit pulp (Passiflora edulis Sims f. flavicarpa Degener, Passifloraceae). Extraction of flavonoids was optimized by experimental design methodology, and quantitative analysis was performed by high-performance liquid chromatography with photo-diode array detection (HPLC-UV/DAD). The method was developed and validated according to ICH requirements for specificity, linearity, accuracy, precision (repeatability and intermediate precision). LOD and LOQ. Rutin was chosen as standard for the quantification of total flavonoids in order to propose a HPLC method feasible for routine analysis of the flavonoids in the passion fruit pulp. The passion fruit pulp contained 16.226 +/- 0.050 mg L(-1) of isoorientin and 158.037 +/- 0.602 mg L(-1) of total flavonoid, suggesting that P. edulis fruits may be comparable with other flavonoid food sources such as orange juice or sugarcane juice. (C) 2010 Elsevier B.V. All rights reserved.

Semipreparative enantioseparation of methamidophos by HPLC-UV and preliminary in vitro study of butyrylcholinesterase inhibition

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Development of an HPLC-UV/Vis method for the determination of dyes in a gasoline sample employing different pre-treatments

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of sugar cane herbicides in soil and soil treated with sugar cane vinasse by solid-phase extraction and HPLC-UV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

An HPLC-UV method for the quantification of zidovudine in rat plasma

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)