title: Determination of ivermectin in bovine liver by optical immunobiosensor.
abstract: A rapid and sensitive biosensor immunoassay was developed for residues of the antiparasitic agent ivermectin in bovine liver. A detection limit of 19.1 ng g(-1) was achieved. The sensor employed was a Biacore optical instrument based on surface plasmon resonance. 5-O-succinoylivermectin-apo-transferrin conjugate was used to produce monoclonal antibody while a second derivative, ivermectin-oxime, was immobilised onto the surface of a sensor chip. A range of assay parameters (flow rate, injection time, temperature) and extraction techniques were investigated. In the final assay procedure, ivermectin was extracted with acetonitrile followed by C(8) SPE clean-up. Matrix effect was minimised by increasing the flow rate to 25 microl min(-1) and reducing the sample injection time to 2 min. The average value for liver samples spiked at 100 ng g(-1) (the MRL for the drug) and 50 ng g(-1) concentrations were 93.7 and 43.2 ng g(-1), respectively.
authors.affiliation: Department of Veterinary Science, Queen's University of Belfast, Stoney Road, Stormont, BT4 3SD, Belfast, UK. jvs@enzyme.chem.msu.ru
authors.forename: Jeanne V
authors.initials: JV
authors.lastname: Samsonova
authors.forename: G Andrew
authors.initials: GA
authors.lastname: Baxter
authors.forename: Steven R H
authors.initials: SR
authors.lastname: Crooks
authors.forename: Amanda E
authors.initials: AE
authors.lastname: Small
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Elliott
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods; D002138:Calibration; D002417:Cattle; D005240:Feasibility Studies; D006863:Hydrogen-Ion Concentration; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods*; D007559:Ivermectin / Q000031:analogs & derivatives / Q000032:analysis*; D008099:Liver / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D012680:Sensitivity and Specificity; D013696:Temperature
chemical_list: D000911:Antibodies, Monoclonal; D007559:Ivermectin