Development a multiple analysis for some organo phosphorus and triazole pesticides by gas chromatography

In this work, a new gas chromotographic (GC) multi-analysis method was developed for the determination of organophosphorus pesticide; chlorpyrifos-methyl and triazole pesticides; triadimefon, penconazole, hexaconazole, diniconazole using electron capture detector (ECD), nitrogen phosphorus detector (NPD) and flame ionization detector (FID).A linear calibration graph was obtained for 5 pesticides within the concentration range of 1.0 ? 5.0 µg/mL using ECD and NPD, and 10.0 ? 50.0 µg/mL using FID. The limit of detection (LOD) and limit of quantification (LOQ) values were also calculated. In order to show the applicability of the proposed method, the optimized method was applied for the residue analysis of tomatoes and eggplant samples. The most suitable detector for the simultaneous determination of 5 pesticides in tomatoes was NPD, the percent relative standard deviation and recovery values were obtained within the range of % 5.0-13.1 and % 62-109, respectively. The percent relative standard deviation and recovery values for eggplant in the same conditions were within the range of % 3.2-18.0 and % 66-104, respectively.This method was also applied for the determination of pesticide active substances in commercial formulations and the percent relative error and recovery values for ECD, NPD and FID were obtained within the range of % 3.9-13.2 and % 86.8-104.9; % 1.5-7.2 and % 96.3-107.2; % 7.4-27.9 and % 72.1-92.6, respectively. For the multi residue analysis of 5 pesticides in tomatoes and eggplant and active substances in commercial formulations, NPD was more suitable detector compared to ECD and FID.