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Coccidiostats in Milk: Development of a Multi-Residue Method and Transfer of Salinomycin and Lasalocid From Contaminated Feed

Konrad Pietruk, Małgorzata Olejnik, Andrzej Posyniak

Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2018 Aug;35(8):1508-1518.

PMID: 29648988

Abstract:

A confirmatory multi-residue method was developed for the determination in milk of 19 coccidiostats (amprolium, arprinocid, clazuril, clopidol, decoquinate, diclazuril, ethopabate, halofuginone, lasalocid, maduramicin, monensin, narasin, nicarbazin, nequinate, robenidine, salinomycin, semduramicin, toltrazuril sulfone and toltrazuril sulfoxide). Sample preparation utilising extraction with organic solvent and clean up by SPE and freezing was found reliable and time-efficient. Optimised chromatography and MS conditions with positive and negative ESI achieved sufficient sensitivity and selectivity. Validation experiments has proven method usefulness for routine analysis of coccidiostats in milk samples. An on-farm study conducted on dairy cows fed with experimentally contaminated feed with salinomycin and lasalocid showed negligible transfer to milk. No residues of lasalocid were found in collected samples. Salinomycin was found only in 5 of 168 samples analysed, while the concentrations of salinomycin in those samples (0.119-0.179 µg kg-1) was significantly below the limit of salinomycin in milk set by European Union legislation. Such low concentrations of both coccidiostats cannot be explained by conjugation during dairy cows' metabolism, as shown by experiments with enzymatic hydrolysis.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP69004155 Toltrazuril sulfoxide Toltrazuril sulfoxide 69004-15-5 Price
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