Recent developments in the analysis of avermectin and milbemycin residues in food safety and the environment.

A review of the developments on the analysis of residues of avermectins and milbemycins (both macrocyclic lactones) is presented. The macrocyclic lactones (MLs) are an important class of chemicals, which are used worldwide as veterinary drugs and as crop protection agents. As a result, residues of MLs are important from both a food safety and environmental perspective. A review of the developments in ML residues in food was carried out in detail in 2006. As a result, this paper covers recent developments in the area of food analysis, which are mainly multi-residue assays based on liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). A brief coverage of HPLC fluorescence (HPLC-FLD) based methods is included for completeness. The paper will carry out a comprehensive review of ML residues in environmental samples. These additional sections are reflective of the growing number of research papers published on LC-MS/MS and environmental applications in recent years.

Detection of benzimidazole carbamates and amino metabolites in liver by surface plasmon resonance-biosensor.

Two surface plasmon resonance (SPR) biosensor screening assays were developed and validated to detect 11 benzimidazole carbamate (BZT) and four amino-benzimidazole veterinary drug residues in liver tissue. The assays used polyclonal antibodies, raised in sheep, to detect BZTs and amino-benzimidazoles. A modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction method was developed to isolate benzimidazole carbamate residues. Liver samples were extracted using an acetonitrile extraction method. BZTs were purified by dispersive solid phase extraction (d-SPE) using C(18) sorbent. Residues of amino-benzimidazoles were effectively cleaned-up using a simple cyclohexane defatting step. The assays were validated in accordance with the performance criteria described in 2002/657/EC. The BZT assay limit of detection was calculated to be 32 µg kg(-1), the detection capability (CCß) was determined to be 50 µg kg(-1) and the mean recovery of analytes was in the range 77-132%. The amino-benzimidazole assay limit of detection was determined to be 41 µg kg(-1), the CCß was determined to be 75 µg kg(-1) and analyte recovery was in the range 103-116%. Biosensor assay performance was tested by analysing liver tissue from animals treated with benzimidazole drugs and comparing the results with an ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) confirmatory method. All non-compliant samples were identified using the biosensor assays.

Benzimidazole carbamate residues in milk: Detection by Surface Plasmon Resonance-biosensor, using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method for extraction.

A surface plasmon resonance (SPR) biosensor screening assay was developed and validated to detect 11 benzimidazole carbamate (BZT) veterinary drug residues in milk. The polyclonal antibody used was raised in sheep against a methyl 5(6)-[(carboxypentyl)-thio]-2-benzimidazole carbamate protein conjugate. A sample preparation procedure was developed using a modified QuEChERS method. BZT residues were extracted from milk using liquid extraction/partition with a dispersive solid phase extraction clean-up step. The assay was validated in accordance with the performance criteria described in 2002/657/EC. The limit of detection of the assay was calculated from the analysis of 20 known negative milk samples to be 2.7mugkg(-1). The detection capability (CCbeta) of the assay was determined to be 5mugkg(-1) for 11 benzimidazole residues and the mean recovery of analytes was in the range 81-116%. A comparison was made between the SPR-biosensor and UPLC-MS/MS analyses of milk samples (n=26) taken from cows treated different benzimidazole products, demonstrating the SPR-biosensor assay to be fit for purpose.