Rapid immunochemical tests for qualitative and quantitative determination of T-2 and HT-2 toxins

Abstract

Rapid immunotests were developed for qualitative and quantitative detection of T-2 and HT-2 toxins in cereal samples. Specific antibodies were immobilized either onto polyethylene filters or sepharose gel inside the transparent column. The tests combined the basic functions of purification, concentration and immunodetection of the target analytes through the enzymatic reaction of horseradish peroxidase (HRP). To make the test suitable for detection of both T-2 and HT-2 toxins, anti-T-2 toxin antibody was combined with HT-2 toxin–HRP conjugate. Matrix interference was eliminated by appropriate dilution of sample extracts with polyethylenglycol solution followed by filtration through a solid sorbent in a separate clean-up column. For the qualitative assay (visual detection) the cut-off level was 2 ng mL⁻¹ of T-2 and HT-2 toxins, while the quantitative assay enabled the detection of 0.55 ng g⁻¹ T-2 toxin and 1.7 ng g⁻¹ HT-2 toxin in spiked wheat samples. Analysis of naturally contaminated wheat samples resulted in a good agreement between the developed immunotest and confirmatory LC-MS/MS. The proposed immunotest is fast, easy-to-use and suitable for rapid screening of T-2 and HT-2 toxins in wheat.