Development and Method Validation of Ochratoxin A Analysis in Cereals using High Performance Liquid Chromatography - High Resolution Mass Spectrometry

Abstract

The objective of this study was to develop an analytical method for ochratoxin A in cereals, modified from AOAC official method 2000.03 using high performance liquid chromatography - high resolution mass spectrometry (HPLC-HRMS). The ion polarity (negative and positive mode) and the different ratios between 0.1% formic acid in water (v/v) and acetonitrile in mobile phase at 20:80, 30:70 and 40:60 were studied. We found that optimal conditions for ochratoxin A analysis using HPLC-HRMS were negative mode for ion polarity and 0.1% formic acid in water – acetonitrile ratio of 30: 70 as HPLC mobile phase. The method was then validated to ensure that it would deliver reliable results. The validation results demonstrated that the working range, limit of detection and limit of quantitation were 0.50 – 20 μ g/kg, 0.20 μ g/kg and 0.50 μ g/kg, respectively. Moreover, the accuracy and precision of the method are within acceptance criteria. (%Recovery 72.54 - 116.60, %RSD 13.10 - 13.69). All results demonstrated that the developed method could detect the presence of ochratoxin A in cereals at the level below permitted levels of the importing countries’ regulation. The method is accredited ISO/IEC 17025 by Bureau of Laboratory Standards, Department of Medical Sciences. and is being used as a standard method for ochratoxin A analysis in cereal at laboratory of Plant Standard and Certification Division, Department of Agriculture.