Liquid chromatographic multicomponent method for determination of residues of ipronidazole, ronidazole, and dimetridazole and some relevant metabolites in eggs, plasma, and feces and its use in depletion studies in laying hens.
(1991)
Journal - Journal - Association of Official Analytical Chemists (UNITED STATES )
Abstract :
A simple, rapid liquid chromatographic (LC) method that uses UV/VIS detection has been developed for the determination in eggs of residues of the histomonostats dimetridazole (DMZ), ronidazole (RON), ipronidazole (IPR), and side-chain hydroxylated metabolites of DMZ and RON. Sample pretreatment includes an aqueous extraction, purification with an Extrelut cartridge, and acid partitioning with isooctane. An aliquot of the final aqueous extract is injected into a reverse-phase LC system; detection is performed at 313 nm. The limits of determination are in the 5-10 microgram/kg range. A UV/VIS spectrum can be obtained at the 10 microgram/kg level by using diode-array UV/VIS detection. Recoveries are between 80 and 98% with a coefficient of variation of about 5%. Some 20 samples can be analyzed per day. A side-chain hydroxylated metabolite of IPR can also be detected with this method, as demonstrated with samples from animal experiments. After a single oral dose of the drugs to laying hens, residues of the parent compound and/or the hydroxylated metabolites could be detected in eggs 5-8 days after dosing. Plasma distribution and excretion in feces were established both with and without deconjugation. DMZ and IPR were extensively metabolized to hydroxylated nitroimidazole metabolites; RON was excreted mainly as the parent compound.
| ISSN : | 0004-5756 |
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| Mesh Heading : | Animals Chickens Chromatography, Liquid Dimetridazole Drug Residues Eggs Feces Female Indicators and Reagents Ipronidazole Magnetic Resonance Spectroscopy Mass Spectrometry Nitroimidazoles Ronidazole Solutions analysis blood analysis blood blood analysis blood |
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| Mesh Heading Relevant : | analysis analysis chemistry analysis |
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Liquid chromatographic determination of carbadox in complete feeds, premixes, and concentrates: interlaboratory study.
(1988)
Journal - Journal - Association of Official Analytical Chemists (UNITED STATES )
Abstract :
A liquid chromatographic (LC) method previously published for the determination of carbadox in finished feeds and premixes was slightly modified and tested in an interlaboratory study. The feed samples are extracted with methanol-acetonitrile (50 + 50) after wetting with water. The extracts are purified over a short alumina column. An aliquot of the eluate is analyzed with reverse phase liquid chromatography with ultraviolet detection. Before the actual interlaboratory study, a prestudy with 2 familiarization feed samples was performed. For the interlaboratory study, 2 series of meal and pelleted samples were prepared with carbadox from different suppliers. Eight collaborating laboratories received 6 feed samples previously milled and ground and 4 pelleted samples which had to be ground by the collaborator's in-house method. Collaborators also received 3 carbadox concentrates (about 10% w/w) and 4 premix samples derived from the concentrates (about 1% w/w). Coefficients of variation under reproducibility conditions were 8.3% for meal samples and 4.9% for pellets. A minor but significant effect was noted for the influence of pelleting temperature on the carbadox content. A minor and insignificant effect was observed for the influence of the milling and grinding procedure on the carbadox content. Alumina cleanup of 1% premixes was not essential, although the resulting chromatograms were cleaner. A slight difference in reproducibility was observed with concentrates (10%) when 0.2 or 0.5 g sample size was used, although the average carbadox concentration found was the same. For premixes and concentrates, coefficients of variation under reproducibility conditions were low, ranging from 2.9 to 7.5%.
| ISSN : | 0004-5756 |
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| Mesh Heading : | Animal Feed Carbadox Chromatography, Liquid Indicators and Reagents Quinoxalines Solvents |
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| Mesh Heading Relevant : | analysis analysis analysis |
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