Proficiency testing as a tool to evaluate performance of LC-MS/(MS) multi-mycotoxin methods in view of EU regulation

A proficiency test (PT) was organized for LC-MS/(MS) multi-mycotoxin methods for the determination of eleven mycotoxins (aflatoxins B1, B2, G1 and G2, ochratoxin A, deoxynivalenol, T-2 and HT-2 toxins, zearalenone, and fumonisins B1 and B2) in maize. This PT was earlier described by M. Solfrizzo+ and A. De Girolamo?. Although the different performance criteria for mycotoxins stated in the Commission Regulation (EC) no 519/2014 are based more or less on single-mycotoxin methods, the performance of the multi-mycotoxin methods was assessed by DUCARES against the 'single-mycotoxin methods' requirements of the European Commission. The data assessment, with the requirements of the European Commission as the target standard deviation (?p) values, was made on a naturally contaminated maize sample and a spiked maize sample. The z-score performance per mycotoxin was divided in three categories, namely |z| <=2 satisfactory, 2< |z| <=3 questionable, |z| >3 unsatisfactory. For the naturally contaminated maize sample the percentage of satisfactory z-score values (|z| <=2) was for ten mycotoxins between 68% and 89%. For one mycotoxin (HT-2 toxin) a satisfactory performance of 97% was obtained. For the spiked maize sample the percentage of satisfactory z-score values (|z| <=2) was between 43% and 94% for eight mycotoxins. For three mycotoxins a satisfactory performance was obtained of 100% (T-2 toxin), 97% (HT-2 toxin) and 97% (aflatoxin G2). The LC-MS/(MS) multi-mycotoxin methods do not meet the performance criteria for most of the mycotoxins in both maize samples in view of the Commission Regulation (EC) no 519/2014. +Results of a proficiency test for multi-mycotoxin determination in maize by using methods based on LC-MS/(MS), M. Solfrizzo et al, Quality Assurance and Safety of crops & foods, March 2013; 5 (1): 15-48 ?Critical evaluation of LC-MS-based methods for simultaneous determination of deoxynivalenol, ochratoxin A, zearalenone, aflatoxins, fumonisins and T-2/HT-2 toxins in maize, A. De Girolamo et al, World Mycotoxin Journal, August 2013; 6 (3): 317-334