Capillary GC Determination of Residual Amounts of 20 Organochlorine Pesticides in Medicine “Sanjiuweitai”

GC was applied to the determination of residual amounts of 20 organochlorine pesticides (OCP′s) in medicine “Sanjiuweitai”. The sample was extracted with n-hexane, and the extract was sulphonated with H2SO4. DB-1701P (30 m×0.25 mm, 0.5 μm) chromatographic column was used for separation in the temperature range from 100 ℃ to 250 ℃ with programmed temperature elevation, and ECD was adopted in the determination. Values of detection limits (3S/N) for the 20 OCP′s were same to be 10 μg·kg-1. Recovery of the method was tested, giving values of recovery ranged from 70.2%-117% and RSD′s (n=6) ranged from 1.0%-1.8%.