Determination of 72 Chemical Pesticides and Estimation of Measurement of Uncertainty in Rice Using LC-MS/MS and GC-MS/MS

Abstract

A multi-residue method was developed and validated for the simultaneous determination of 39 and 33 chemical pesticides in rice using LC-MS/MS and GC-MS/MS, respectively. The coefficient of determination was 0.994 to 0.999 over the linear concentration range of 0.01 to 0.1 μg mL-1. The LOD and LOQ were in the range of 0.31 to 3.35 and 1.04 to 10.06 μgkg-1, repsectively. The mean recoveries at 0.01, 0.05, and 0.1 mgkg-1 were found within the range 70 to 120% with satisfactory precision (RSD < 15%). Measurement uncertainty (Uexp) values estimated at 0.05 mgkg-1 spiking level were found lower than 20 μgkg-1 for all tested pesticides. A rice and wheat powder check samples under the proficiency test were analyzed using a standardized method, and the Z score recorded within the acceptable range of −2 to +2. The proposed method was applied to analyze the pesticides in real samples collected from the market and quantified the residues. The developed method could be useful for monitoring 72 chemical pesticides in rice matrices and can be adopted for the pesticide monitoring program.