Validation of a Method for Determining Multiple Residual Pesticides in Dried Red Pepper Using LC-MS/MS

An analytical method has been developed and validated for determining 107 pesticide residues in dried red pepper using LC-MS/MS. LC method, the clean-up and sample dilution processes were examined to determine their impact on reducing the matrix effects. Clean up was performed using an ENVI-CarbII (TM)/PSA (300/600 mg, 6 mL) SPE cartridge. In the sample dilution process, eightfold dilution was used. In the validation of the developed method at two concentrations (0.01 and 0.1 mu g/g) for 107 pesticides, 96 pesticides showed recovery rates in the range of 70.1 to 112.6%, RSDs of repeatability of <= 11.5 and 3.4%, and RSDs of within-laboratory reproducibility of <= 24.3 and 19.9% These values fulfill the criteria of the validation guidelines for pesticide residues in Japan. It is concluded that matrix effects and low recovery rates in the process of extraction are the main factors for values that do not conform to the criteria.