Comparative Evaluation of Total Ergot Alkaloids Determination by ELISA and UHPLC-MS/MS in Wheat: Implications of
Chamali Kodikara1,2,3, Dainna Drul1, Nandika Bandara2,3
1Grain Research Laboratory, Canadian Grain Commission, 1404-303 Main Street, Winnipeg, Manitoba R3C 3G8, Canada.
Abstract:
Ergot alkaloids (EAs) are toxic secondary metabolites found in cereal grains that require effective monitoring strategies. This study evaluated a commercially available enzyme-linked immunosorbent assay (ELISA) for total ergot alkaloids against a validated ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) reference method using naturally contaminated wheat and durum samples. Beyond method comparison, the study examined cross-reactivity and matrix effects to explain differences between immunoassay and chromatographic measurements. The ELISA demonstrated good repeatability and calibration stability across kits and days, but systematic bias relative to UHPLC-MS/MS was observed, with ELISA results generally underestimating chromatographic totals. ELISA accuracy assessment using certified reference and proficiency test materials revealed inconsistent bias, including occasional overestimation. ELISA cross-reactivity, based on half-maximal inhibitory concentration (IC50), revealed compound- and matrix-dependent immunochemical effects, explaining the observed discrepancies. These findings support ELISA as a high-throughput screening and prioritization tool while confirming that definitive quantification requires UHPLC-MS/MS confirmation for regulatory purposes.
