Validation of screening methods according to Regulation 519/2014/EU. Determination of deoxynivalenol in wheat by lateral flow immunoassay: a case study.

Recent advances in establishing harmonized guidelines for validation of screening methods are reviewed. Emphasis is given to guidelines set in the Regulation 519/2014/EU that specifies validation criteria for mycotoxin screening methods to be used for official control purposes. The application of this validation scheme is demonstrated through a case study. A commercial lateral flow immunoassay for deoxynivalenol has been and evaluated for its applicability to verify wheat compliance with EC maximum permitted level. The validation design provided information on the precision profile of the method, cut-off, false suspect and false negative rates of samples containing deoxynivalenol above the legal limit. The influence of the co-occurrence of major deoxynivalenol modified forms, i.e. 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, and deoxynivalenol-3-glucoside on test results, was evaluated by a factorial design. Finally, the applicability of the validated immunoassay was demonstrated by analysis of naturally contaminated wheat samples, and comparison with results obtained by a LC-MS/MS confirmatory method.