GC-MS Determination of Residual Organochlorine and Synthetic Pyrethroid Insecticides in Fatty Wool

Hyphenation of GC and MS was applied to the determinations of residual organochlorine and synthetic pyrethroid insecticides in fatty wool.The sample was extracted by carbon dioxide-supercritical fluid extraction,the extract obtained was purified and concentrated by automatic gel permeation chromatography and solid phase extraction with Bond Elut Si SPE column.The eluate from the SPE column was evaporated by N2-blowing and made up to 1.0 mL,which was used for GC-MS analysis.External standard method was adopted in the determination.Working curves of the 11 organochlorine insecticides and 5 pyrethroid insecticides were found to have good linearity.Limits of detection (3S/N) and lower limits of determination (10S/N) for the insecticides were found in range of 0.022-0.32 mg·kg-1 and 0.073-1.07 mg·kg-1,respectively.Tests for recovery and precision were made by standard addition method at 3 different concentration levels,values of recovery found were in the range of 74.8%-135.2% and values of RSD′s (n=6) were less than 10%.