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 °C.

Occurrence of zearalenone and its major metabolites in cereal flour from Korea.

The occurrence of zearalenone (ZEN) and its metabolites (α-zearalenol (α-ZEL), β-zearalenol (β-ZEL), α-zearalanol (α-ZAL), β-zearalanol (β-ZAL), and zearalanone (ZAN)) was investigated in 78 cereal flour from Korea using UHPLC-MS/MS. Among these mycotoxins, ZEN was the most abundant in the analyzed samples at an incidence rate of 41% and concentration range of 0.5-536 µg/kg.

Accurate determination of four tetracycline residues in chicken meat by isotope dilution-liquid chromatography/tandem mass spectrometry.

An analytical method based on isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC‒MS/MS) was developed to accurately determine four representative tetracyclines (tetracycline, chlortetracycline, doxycycline, and oxytetracycline) in chicken meat. Tetracyclines are known to have a great tendency for epimerization and keto-enol tautomerism, which often provoke major challenges in their determination. Since this isomerization was found to be unavoidable during the whole chain of the current analysis, the total content (µg kg) of individual tetracycline was quantified as a sum of each parent compound and its respective isomeric forms.

Development of a certified reference material for the accurate determination of type B trichothecenes in corn.

A corn flour certified reference material (KRISS CRM 108-01-011) was developed to ensure accurate and reliable measurements of type B trichothecenes (deoxynivalenol, nivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol), and deoxynivalenol-3-glucoside. The material was freeze-dried, ground, sieved, and well-mixed. The final produced CRM was packaged at 14 g per unit and stored at -70 °C.

Development of isotope dilution-liquid chromatography/tandem mass spectrometry for the accurate determination of zearalenone and its metabolites in corn.

A method using isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC/MS/MS) was developed for the accurate determination of zearalenone (ZEN) and its five major metabolites in corn. C- or H-labeled analogues of the target mycotoxins were used as internal standards. As the immunoaffinity columns used demonstrated selectivity to a specific chiral isomer of a racemic mixture of zearalanone-d, a clean-up cartridge without stereoselectivity (Mycosep 226 column) was selected for the same recovery of the analyte and its internal standard with adequate elimination of matrix interferences.