2018 Volume 25 Issue 3 Pages 160-166
A screening method for deoxynivalenol (DON) residue in beer by use of a commercially available ELISA-kit was applied for its accuracy management for method validation. DON in beer sample was subjected to acetonitrile extraction and cleanup with a MycoSep #227 multifunctional column. Recovery experiments indicated that the trueness of the low concentration sample (10 ng/ mL) and that of the high concentration sample (100 ng/mL) were higher than 90%, respectively. The relative standard deviation (RSD) of repeatability and that of intermediate precision were less than 25%, respectively. In addition, the interlaboratory precision of seven laboratories was determined as an external quality control test with and without sample cleanup. The interlaboratory precision of the high concentration sample (100 ng/mL) showed an acceptable Z-score (less than 2.0 and greater than -2.0; |z| < 2) for all the seven laboratories, regardless of whether or not cleanup was performed. In addition, the gap between the added concentration and the average value (most probable value) was less than 20%. On the other hand, in the case of the low concentration sample (10 ng/mL) without cleanup, the Z-scores were “|z| < 2” for all the seven laboratories, but the residual variance was large and the deviation from the most probable value was increased. However, by performing cleanup pretreatment, DON concentrations down to 10 ng/mL could be measured by ELISA. Then, sixteen commercially available beer samples were subjected to DON determination using the present ELISA and a confirmation test using GC/MS. DON was detected in 9 beer samples (56.3%); the mean concentration was 14.3 ng/mL and the highest concentration was 54.8 ng/mL. The correlation coefficient (r) was high at 0.887. The results suggest that the ELISA-kit with the cleanup method is useful for a screening of low level DON in beer.
