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The isolation of drug residues, environmental contaminants or naturally occurring component molecules from biological materials is often a complex undertaking. We report here the development and application of a simple approach to the disruption of biological samples that also allows for the rapid fractionation and isolation of the sample's natural(More)
A liquid chromatographic (LC) method is described for the simultaneous determination of xylazine (XY) and its major metabolite, 2,6-dimethylaniline (2,6-DMA), in bovine and swine kidney in the 25-100 ppb range. XY and 2,6-DMA are extracted from kidney with chloroform, followed by cleanup on an acidic Celite 545 column. A mu Bondapak phenyl column is used(More)
Fatty acid methyl esters (FAMEs) of pure triglyceride standards, oils, and fat from dry matrixes were formed by transesterification using sodium methoxide in methanol-hexane. FAMEs were produced by direct addition of sodium methoxide-hexane to samples and heating to simultaneously extract and transesterify acyl lipids. FAMEs were quantitated by capillary(More)
A liquid chromatographic (LC) method was developed for the simultaneous determination of nitrofurazone (NFZ), nitrofurantoin (NFT), and furazolidone (FZD) in catfish muscle tissue. The drugs were extracted from the tissue with acetonitrile, and the lipids were removed from the extract with hexane. The acetonitrile extract was evaporated by rotary(More)
A liquid chromatographic (LC) method is described for the simultaneous determination of the triazine herbicides, simazine (SIM), atrazine (ATZ), and propazine (PRO) in the 12.5-100 ppb range in catfish. The herbicides are extracted from catfish homogenates with ethyl acetate, followed by solvent partitioning between acetonitrile and petroleum ether and(More)
A new method based on solid phase dispersion of tissue for the subsequent isolation of drugs is reported. By blending tissues with a polymeric phase bound to a solid support one obtains a semi-dry material which can be used as a column packing material from which one can isolate drugs in a stepwise fashion based on the solubility characteristics of the(More)
Eight triphenylmethane dyes (malachite green, leucomalachite green, gentian violet, leucogentian violet, brilliant green, pentamethyl gentian violet, N',N'-tetramethyl gentian violet and N',N"-tetramethyl gentian violet) have been characterized by particle beam liquid chromatography-mass spectrometry. The electron ionization spectra obtained of these dyes(More)
A gas chromatographic/mass spectrometric (GC/MS) method was developed to confirm the presence of leucomalachite green (LMG), a metabolite of the triphenylmethane dye malachite green (MG), in catfish tissue. Residues were isolated according to a previously described liquid chromatographic (LC)/VIS spectrometric analysis of MG and LMG in fish. In our(More)
A liquid chromatographic (LC) method was developed for the determination of flunixin (FNX) in raw bovine milk. The milk was acidified and mixed with silica gel, and the mixture was packed into a chromatographic column. The column was defatted with water-saturated dichloromethane-hexane (30 + 70, v/v), and the analyte was eluted with EtOAc. The EtOAc extract(More)
A multiresidue method for isolation and liquid chromatographic determination of 5 benzimidazole anthelmintics (thiabendazole, oxfendazole, mebendazole, albendazole, and fenbendazole) in beef liver tissue is presented. Blank or benzimidazole-fortified liver samples (0.5 g) were blended with octadecylsilyl derivatized silica packing material (C18, 18% load,(More)