Simultaneous determination of residues of 28 organophosphorus pesticides in tobacco by gas chromatography with dual columns and double detectors
For rapidly detecting the residues of 28 organophosphorus pesticides in tobacco, a gas chromatography (GC) with double columns and dual detectors was developed via investigating the effects of sample pretreatment conditions and chromatographic separating conditions, such as carrier gas, temperature, etc., on the recoveries and separation of the pesticides. The results showed that: 1) the 28 organophosphorus pesticides could be divided into 2 groups to be separated with DB-1701 and DB-XLB capillary columns, respectively. 2) The recoveries of the tested pesticides ranged from 60.2% to 114.8% with the relative standard deviations of 0.83% to 9.75% and limits of detection of 0.009 to 0.029 mg/kg. The method is suitable for the rapid determination of multi-residues of organophosphorus pesticides in tobacco.