Submitted to: Food and Agricultural Immunology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/3/2002
Publication Date: 9/1/2002
Citation: Johnsson, L., Baxter, G.A., Crooks, S.R.H., Brandon, D.L., Elliott, C.T. 2002. Reduction of sample matrix effects-the analysis of benzimidazole residues in serum by immunobiosensor. Food and Agricultural Immunology. 14(3):209-214. Interpretive Summary: Regulatory authorities, the food industry and the consumer demand the reliable determination of chemical contaminants present in food. A relatively new analytical technique that addresses this need is an immunobiosemsor based on measuring changes in the refraction of light. A considerable problem has been encountered in making measurments in both serum and plasma samples. This paper describes a simple technique to remove interfering substances from serum samples, enabling measurements to be made using the immunobiosensor. This technique was used to measure the presence of anti-worm drugs in sera from cattle.
Technical Abstract: Regulatory authorities, the food industry and the consumer demand the reliable determination of chemical contaminants present in foods. A relativity new analytical technique that addesses the need is an immunobiosensor based on surface plasmon resonance (SPR) measurements. Although a range of tests have been developed to measure residues in milk, meat, animal bile and honey, a considerable problem has been encountered with both serum and plasma samples. The higher degree of non-specific binding of some components can lead to loss of assay robustness, increased rates of false positives and general loss of assay sensitivity. In this paper we describe a straightforward precipitation technique to remove interfering substances from serum samples to be analysed for veterinary anthelmintic by SPR. This technique enabled development of an assay to detect a wide range of benzimidazole residues in serum samples by immunobiosensor. The limit of quantification was below 5 ng/ml and coefficents of variation were about 2%.