Validation of automated Library-Based Qualitative Screening of Pesticides by Comprehensive Two-Dimensional Gas Chromatography/Time-of-Flight Mass Spectrometry

A method for automated detection and reporting of pesticides in plant materials based on comprehensive two-dimensional GC/time-of-flight MS with library-based detection by software has been developed and validated. Optimum settings for detection parameters such as spectral match threshold and first and second dimension retention time tolerances were assessed with respect to occurrence of false detects and false negatives. Next the method was validated following European Union guidelines established for qualitative screening of pesticides. The validation was largely done in retrospect by using data obtained for spiked samples (235 pesticides, various crops, 0.01-0.2 mg/kg) that had been analyzed previously with routine samples over a period of 18 months. At 0.01 mg/kg, the required 95% confidence level