Development of a corn flour certified reference material for the accurate determination of zearalenone

A certified reference material (CRM, KRISS 108-01-002) for zearalenone in corn flour was developed to assure reliable and accurate measurements in testing laboratories. Commercially available corn flour underwent freeze-drying, pulverization, sieving, and homogenization. The final product was packed in amber bottles, approximately 14 g per unit, and preserved at -70 degrees C. 13C18-Zearalenone was used as an internal standard (IS) for the certification of zearalenone by isotope-dilution liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) and for the analysis of alpha-zearalenol, beta-zearalenol, and zearalanone by LC-MS/MS. The prepared CRM was sufficiently homogeneous, as the among-unit relative standard deviation for each mycotoxin ranged from 2.2 to 5.7 %. Additionally, the stability of the mycotoxins in the CRM was evaluated under different temperature conditions and scheduled test periods, including storage at -70 degrees C, -20 degrees C, and 4 degrees C and room temperature for up to 12 months, 6 months, and 1 month, respectively. The content of each target mycotoxin in the CRM remained stable throughout the monitoring period at each temperature. Zearalenone content (153.6 +/- 8.0 mu g/kg) was assigned as the certified value. Meanwhile, the contents of alpha-zearalenol (1.30 +/- 0.17 mu g/kg), beta-zearalenol (4.75 +/- 0.33 mu g/kg), and zearalanone (2.09 +/- 0.16 mu g/kg) were provided as informative values.