Comprehensive two-dimensional gas chromatography with flame photometric detection applied to organophosphorus pesticides in food matrices

Abstract

Comprehensive two-dimensional gas chromatography coupled with a flame photometric detector (GC×GC-FPD) was developed for analysis of 16 organophosphorus pesticides (OPs) in food matrices. The column set, modulation period and modulator temperature were investigated in this study, and suitable conditions chosen. Three pairs of co-eluting OPs in 1D GC were baseline separated in GC×GC with a non-polar/polar column set (DB-5×DB-1701), a 4s modulation period, and modulator temperature of 50°C. Compared to GC-FPD, the identification of OPs is more accurate in GC×GC due to the additional identification parameter, 2tR. Second dimension tR reproducibility is in the range 0–0.85% RSD in GC×GC-FPD. Excellent calibration graph linearities were obtained for 16 OPs over the concentration range from 5 to 1000μgL−1. The limits of detection were 1.5–5.6μgL−1 indicating significant improvement compared to those obtained in 1D GC. Six OPs were found at low concentrations (0.79–5.12μgkg−1) in 5 samples analysed in six different food matrices. The good reproducibility of parallel results showed that GC×GC-FPD for OP analysis in food matrices is a satisfactory and valid technology.