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

Comprehensive two-dimensional gas chromatography coupled with a flame photometric detector (GCxGC-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 x GC with a non-polar/polar column set (DB-5xDB-1701), a 4 s modulation period, and modulator temperature of 50 degrees C. Compared to GC-FPD, the identification of OPs is more accurate in GCxGC due to the additional identification parameter, (2)t(R). Second dimension t(R) reproducibility is in the range 0-0.85% RSD in GCxGC-FPD. Excellent calibration graph linearities were obtained for 16 OPs over the concentration range from 5 to 1000 mu g L-1. The limits of detection were 1.5-5.6 mu g L-1 indicating significant improvement compared to those obtained in 1D GC. Six OPs were found at low concentrations (0.79-5.12 mu g kg(-1)) in 5 samples analysed in six different food matrices. The good reproducibility of parallel results showed that GCxGC-FPD for OP analysis in food matrices is a satisfactory and valid technology. (C) 2012 Elsevier B.V. All rights reserved.