A comparison between ELISA and HPLC for aflatoxin B1 and ochratoxin A detection in Iranian red pepper

The aim of this study was to compare high performance liquid chromatography (HPLC)and enzyme linked immunosorbent assay (ELISA) methods for aflatoxin B1 (AFB1) and ochratoxin A (OTA) determination in red pepper spice. For this purpose, thirty six samples of red pepper were collected from farm in Sabzevar (a city in Razavi Khorasan province) and dried in the sun and open air. Among a total of 36 samples, the incidence of AFB1 and OTA was (28) 77.8% and 8) 22.2% within the range of 1.1-15.0 μg/kg and 0.59-2.35 μg/kg, respectively, as it was determined by ELISA. In comparison, HPLC detected AFB1 and OTA in 25 (69.4%) and 6 (16.7%) of samples within the range of 0.4-14.5 μg/kg and 0.74-2.17 μg/kg, respectively. Statistically, comparison of the quantitative analysis of AFB1 and OTA by ELISA and HPLC revealed a good correlation (for AFB1 r2 = 0.979, for OTA r2 = 0.947) between both methods but correlation obtained for AFB1 was more accurate and higher than OTA. On the other hand, the levels of AFB1 and OTA determined by ELISA were higher than those determined by HPLC. According to the obtained results, ELISA can be used as a reliable screening method, but the confirmation of positive results must be done by HPLC method.