Determination of nitroimidazole residues in aquaculture tissue using ultra high performance liquid chromatography coupled to tandem mass spectrometry.

An UHPLC-MS/MS method was developed for the quantitative confirmatory analysis of residues of nitroimidazole drugs (dimetridazole, ipronidazole, metronidazole, ornidazole and ronidazole) and their corresponding hydroxy metabolites (HMMNI, ipronidazile-OH and metronidazole-OH) in aquaculture tissue. Samples were extracted by shaking in acetonitrile, water, MgSO4 and NaCl before being defatted with n-hexane pre-saturated with acetonitrile and concentrated under nitrogen. Nitroimidazole residues were determined by UHPLC-MS/MS operating in positive electrospray ionisation mode using a reversed phase BEH C18 column.

Determination of the new anthelmintic monepantel and its sulfone metabolite in milk and muscle using a UHPLC-MS/MS and QuEChERS method.

This is the first paper to report a method for the detection of the new anthelmintic monepantel and its sulfone metabolite in goat's milk and ovine muscle. Samples were extracted and purified using a modified QuEChERS method. A concentration step was included when analyzing in the low μg kg(-1) range.

A dual validation approach to detect anthelmintic residues in bovine liver over an extended concentration range.

This paper describes a method for the detection and quantification of 38 residues of the most widely used anthelmintics (including 26 veterinary drugs belonging to the benzimidazole, macrocyclic lactone and flukicide classes) in bovine liver using two different protocols for MRL and non-MRL levels. A dual validation approach was adopted to reliably quantify anthelmintic residues over an extended concentration range (1-3000 μg kg(-1)). Sample extraction and purification was carried out using a modified QuEChERS method.

Determination of anthelmintic drug residues in milk using ultra high performance liquid chromatography-tandem mass spectrometry with rapid polarity switching.

A new UHPLC-MS/MS (ultra high performance liquid chromatography coupled to tandem mass spectrometry) method was developed and validated to detect 38 anthelmintic drug residues, consisting of benzimidazoles, avermectins and flukicides. A modified QuEChERS-type extraction method was developed with an added concentration step to detect most of the analytes at <1 microg kg(-1) levels in milk. Anthelmintic residues were extracted into acetonitrile using magnesium sulphate and sodium chloride to induce liquid-liquid partitioning followed by dispersive solid phase extraction for cleanup.

Current trends in sample preparation for growth promoter and veterinary drug residue analysis.

A comprehensive review is presented on the current trends in sample preparation for the isolation of veterinary drugs and growth promoters from foods. The objective of the review is to firstly give an overview of the sample preparation techniques that are applied in field. The review will focus on new techniques and technologies, which improve efficiency and coverage of residues.