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Two Proficiency Testings (PTs) involving eighteen laboratory participants from 10 Countries have been conducted in 2014 for the simultaneous determination of deoxynivalenol, fumonisins B 1 and B 2 , zearalenone, T-2 and HT-2 toxins, ochratoxin A and aflatoxins B 1 , B 2 , G 1 and G 2 in maize and of deoxynivalenol, zearalenone, T-2 and HT-2 toxins and ochratoxin A in wheat, respectively. The aim of PTs was to check next to the laboratory performance the state-of-art of the LC–MS multi-mycotoxin methods used by participants. In addition, the trend of performances of LC–MS methods for multi-mycotoxin determination in maize together with method-related issues was assessed by comparing three PTs organised over the years 2011–2014. Data showed the improvement of laboratory performances with the overall acceptable z-scores that progressively increased from 59% in 2011 PT to 85% in 2014 PT, while the rate of unacceptable z-score decreased from 25% in 2011 PT to 11% in 2014 PT. [ABSTRACT FROM AUTHOR]

Abstract: A sensitive and reliable liquid chromatography/photoionization (APPI) tandem mass spectrometry method has been developed for determining nine selected mycotoxins in wheat and maize samples. The analytes were chosen on the basis of the mycotoxins under EU Commission Regulation (EC) No. 1881/2006, i.e., deoxynivalenol (DON), zearalenone (ZON), aflatoxins (AFs), and ochratoxin A (OTA), and considering the possibility of a near future regulation for T-2 and HT-2 toxins. Mycotoxins were extracted from samples by means of an one-step solvent extraction without any cleanup. The developed multi-mycotoxin method permits simultaneous, simple, and rapid determination of several co-existing toxins separated in a single chromatographic run, in which AFs, T-2 and HT-2 toxin are acquired in positive, while OTA, DON and ZON in negative mode. Although a moderate signal suppression was noticeable, matrix effect did not give significant differences at p =0.05. Then, calibration in standard solution were used for quantitation. Based on the EU Commission Decision 2002/657/EC, the method was in-house validated in terms of ruggedness, specificity, linearity, trueness, within-laboratory reproducibility, decision limit (CCα) and detection capability (CCβ). For all the analytes, the regression coefficient r ranged between 0.8752 (DON in wheat) and 0.9465 (ZON in maize), biases related to mean concentrations were from −13% to +12% of the nominal spiking level, and the overall within-laboratory reproducibility ranged 3–16%; finally, CCα values did not differ more than 20% and CCβ not more than 42% from their respective maximum limit. Method quantification limits ranged from 1/20 (AFG1) to 1/4 (AFG2 and OTA) the maximum limit established by European Union in the Commission Regulation (EC) No. 1881/2006 and its subsequent amendments. [Copyright &y& Elsevier]

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