New approach to quantitative analysis of benzo[a]pyrene in food supplements by an immunochemical column test

A quantitative immunochemical rapid test for sensitive determination of benzo[a]pyrene (BAP) as a model analyte was developed making use of a handheld reader for results evaluation. The covalent immobilization of antibodies to different Sepharose gels, i.e., CNBr-activated Sepharose 4B and CNBr-activated Sepharose 4 Fast Flow was compared with adsorption to a polyethylene support. The lowest limits of detection (LOD) were 4 ng L−1 and 40 ng L−1, respectively, using optimized assay conditions. The developed test was applied to food supplements (garlic, black radish and maca), including a pretreatment procedure. LOD of 9 ng kg−1 and linear range of 13-80 ng kg−1 were obtained. Results of BAP determination in naturally contaminated samples were confirmed by high-performance liquid chromatography coupled to fluorescence detection and a good correlation was achieved. We suggest that the developed test format can be used to quantitative detection of the low molecular weight analytes, such as mycotoxins, pesticides, other pollutants in food and environmental samples.