Determination of uncertainty in the measurement of Aflatoxins B1 in pistachio nuts by the HPLC-FLD method

Abstract

The present study defined uncertainties during Aflatoxin B1 measurements in pistachio nuts using HPLC equipped with fluorescence detector and derivatizing cell (Kobra® Cell) to increase the detector signal. The uncertainty of a method is one of the parameters required by EURACHEM/CITAC Guide, and forms part of the validation of analytical methods. Six variables affected the final value of the measured concentration, which were included in the mathematical model. The contribution index of each variable to the combined uncertainty (uc) was also calculated and analysis of the Pareto diagram showed that 80.47% of the variability was the result of the calculation and execution of the calibration curve of the Aflatoxin B1 standard, 19% was determined by the recovery rate of the pistachio sample and volumetric measurements affected the concentration to a very lesser extent. The value of expanded uncertainty in the determination of Aflatoxin B1 for pistachios was Ucx = 0.83 μg/kg.