Chemometric Approach Based on Accuracy Profile and Data Chronological Distribution as a Tool to Detect Performance Degradation and Improve the Analytical Quality Control for Aflatoxins' Analysis in Almonds Using UPLC-MS/MS.

One of the main objectives of routine laboratories is the development of simple and reliable methods as well as meeting fit-for-purpose criteria for regulatory surveillance. In this study, the accuracy profiles and the evaluation of the distribution of results in the case of aflatoxins in almonds have been performed using ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The method consists of designing the experiment and using certified reference material (CRM) to evaluate the bias, to calculate the combined uncertainty, and to construct the control charts. Good sensitivity (limit of quantifications (LOQs) 0.34-0.5 μg/kg) and recovery (between 82 and 107%) were achieved. The proposed method was successfully tested with a proficiency test in almond powder with acceptable scores (-2 ≤ ≤ 2). The results provided direct evidence for the proper functioning and stability of the whole analytical protocol, allowing acceptable combined uncertainty.