GC Determination of 11 Organochlorine Pesticides in Honey Peaches with Separation by HS-SPME

GC with separation and enrichment by HS-SPME was applied to the determination of 11 organochlorine pesticides (OCP′s). 5.000 g of the fruit pulp were taken and diluted with 15 mL of H2O. An aliquot of 2.00 mL was placed into a 12 mL ampoule and added with 1.0 g of NaCl. After capping the ampoule tightly, it was placed into a water bath at 70 ℃. A PDMS extractor was inserted into the ampoule with its injector placed at 1.0 cm over the solution level in the head-space. SPE was carried out with stirring at the rate of 600 r·min-1 for 30 min. The extractor was removed from the ampoule and inserted directly into the sample inlet of the chromatograph for thermo-desorption. After desorption for 5 min, the analytes were carried by carrier gas to pass through SE-54 quartz capillary chromatographic column for separation and measured with ECD. Linearities in definite concentration ranges were kept for the 11 OCP′s, and detection limits (3S/N) in the range of 1.33-42.3 ng·kg-1 were found. Recovery and repeatability were tested, giving values of recovery ranged from 90.6% to 112%, and RSD′s (n=5) all less than 10%.