Submitted to: Analytica Chimica Acta
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/22/2009
Publication Date: 9/26/2009
Publication URL: http://handle.nal.usda.gov/10113/55942
Citation: Keegan, J., Whelan, M., Danaher, M., Crooks, S., Sayers, R., Anastasio, A., Elliott, C., Brandon, D.L., Furey, A., O'Kennedy, R. 2009. Benzimidazole Carbamate Residues in Milk: Detection by SPR Biosensor; using a Modified QuEChERS Method for Extraction. Analytica Chimica Acta.Volume(2009):111-119 Interpretive Summary: A new analytical method was developed for the rapid screening of milk samples for residues of benzimidazole veterinary drugs widely used for prevention and treatment of parasitic infections in agriculture and aquaculture. Because some of these anti-worm drugs are used to treat infected cows, analytical methods for detecting drug residues in the milk matrix are needed to ensure compliance with regulatory guidelines. An extensive validation of the assay was carried out for 11 metabolites of these drugs. The method exploits an antibody that binds to the drugs and metabolites, together with an optical biosensor to detect binding in samples containing as little as 5 ppb, with a false negative rate less than 5%. The biosensor instrument is a fully automated system that permits unattended batch-processing of extracted milk samples.
Technical Abstract: 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 2.7 µg kg. The detection capability (CCß) of the assay was determined to be less than or equal to 5 µg kg for 11 benzimidazole residues and the mean recovery of analytes was in the range 69 to 120%.