GC Determination of Organochlorine Pesticides Residues in Houttuynia Cordata by Ultrasonic Assisted Extraction

A method of ultrasonic assisted extraction combined with gas chromatography was used to determine organochlorine pesticides (OCPs) in houttuynia cordata. The sample was extracted by a mixture of acetone and petroleum (1+1) through ultrasonic for 30 min,then purified with concentrated sulphuric acid,concentrated with rotary evaporation,and analyzed with GC-ECD. Linearity range of OCPs was found between 0.001-0.20 mg·L-1,and the detection limit (3S/N) was 0.023-0.29 μg·kg-1. The recovery rates were in the range of 73.0%-115%,higher than those of Chinese Pharmacopoeia method. The values of RSD′s (n=5) were in the range of 1.4%-14%. This method is suitable for detecting OCPs residues in the houttuynia cordata.