Determination of 4 dithiocarbamate residues in 22 matrices by gas chromatography
气相色谱法检测22种基质中的4种二硫代氨基甲酸盐类农药残留

A gas chromatographic method with flame photometric detection (FPD (sulfur filter)) for analyzing the residues of 4 dithiocarbamates in 22 matrices in a heated closed vial has been established. The dithiocarbamate residues were decomposed to carbon disulfide (CS2) by SnCl2-HCl solution. The liberated CS2 was absorbed by hexane in the vial, and then determined by gas chromatography with FPD (sulfur filter). The results were expressed as the residues of dithiocabamates. The residue analysis method was validated by mancozeb, metiram, propineb and thiram in 22 matrices (apple, grape, etc). The average recovery ranges were from 72% to 110% with the relative standard deviations (RSD) between 0.8% and 22.0% when the fortified concentrations were between 0.06 and 3.0 mg/kg, and the quantitative analysis was performed by using external standard method. The limits of detection were in the range of 0.01~0.1 mg/kg (S/N=3), and the limits of quantification were between 0.02 and 0.2 mg/kg (S/N=10) for the 4 dithiocarbamate residues in the 22 matrices. This method is simple, fast, accurate, reproducible, and suitable for the determination of the 4 dithiocarbamate residues in the matrices mentioned in this paper.