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

Abstract

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 µg kg⁻¹) and its performance was compared with LC-MS, quantification limit =140 µg 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 µg kg⁻¹) and in 22 samples (57.9%) by LC-MS (155.3–9906.9 µg 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.

Keywords:

• ELISA
• LC/MS
• inter-laboratory validation
• mycotoxins
• trichothecenes
• cereals and grain

Acknowledgements

The authors acknowledge the CNPq (the Brazilian Government organisation for grant aid and fellowship to Brazilian researchers) in association with MAPA (Ministry of Agriculture, Livestock and Food Supply), the Araucária Foundation (Paraná State grant), Paraná Fund/SETI and CAPES (Coordination for Formation of High Level Professionals) – Nanobiotechnology Network Program (04/CII-2008) for financial support. The CNPq research productivity fellowship is greatly appreciated by E.Y.S. Ono and E.Y. Hirooka, as well CNPq/Dr by J.S. Santos. The authors are grateful to the reviewers whose comments and suggestions have helped to improve this manuscript.