Immunoassay based on monoclonal antibodies versus LC-MS: deoxynivalenol in wheat and flour in Southern Brazil.

An indirect competitive enzyme-linked immunosorbent assay (ELISA) method using a monoclonal antibody for deoxynivalenol (DON) detection in wheat and flour was standardised and validated (detection limit - 177.1 mu g kg(-1)) and its performance was compared with LC-MS, quantification limit = 140 mu g kg(-1)). DON recovery ranged from 88.7% to 122.6% for wheat grain and from 70.6% to 139.3% for flour. Among the 38 wheat samples evaluated, DON was detected in 29 samples (76.3%) by ic-ELISA (281.6-12 291.4 mu g kg(-1)) and in 22 samples (57.9%) by LC-MS (155.3-9906.9 mu g kg(-1)). The 0.93 correlation coefficient between ic-ELISA and LC-MS data in 19 positive DON wheat samples demonstrated the reliability and efficiency of ic-ELISA. Results indicated that standardised ic-ELISA was suitable for DON screening in wheat samples and the need for continuous monitoring of mycotoxin levels in foodstuffs.