超声波辅助提取-气相色谱法测定蔬菜中的有机氯农药残留

Determination of organochlorine pesticide residues in vegetables by using ultrasonic assistant extraction and gas chromatography

对比了超声波提取，振荡提取和索氏提取一气相色谱法测定蔬菜中的有机氯农药残留。结果表明，超声波辅助提取的回收率为82．8％～110．2％，相对标准偏差在3％和15％之间，其回收率高于振荡提取和索氏提取方法，是一种低成本、省时、效率高的方法，能够对蔬菜中多种有机氯农药的提取达到很好的效果。用这种方法对南京市郊蔬菜中有机氯农药残留规律进行分析表明，南京市郊蔬菜中DDTs和六六六的检出率除P，P’-DDD和6-六六六分别为95％和89％外，其余农药的检出率为100％。DDTs是蔬菜中的主要农药残留，其含量高于六六六，分别占残留总量的71．3％～74．9％和25．1％～28．7％。所有蔬菜体内的DDT和六六六的残留量均不超标，但仍会对农产品质量安全构成潜在威胁。

Residues of organochlorine pesticides in vegetables were extracted by using ultrasonic assistant extraction, Soxhlet extraction and oscillation extraction method and analyzed by gas chromatography equipped with a 63Ni electron-capture detector （GC-ECD） system. The results indicated that the extraction efficiency of ultrasonic assistant extraction are between 82.8% and 110. 2% ,relative standard deviation ranging from 3% to 15% ,which is higher than that with Soxhlet extraction and oscillation extraction method. Ultrasonic assistant extraction is a low cost, short-time and high efficiency method for extracting organochlorine pesticides in vegetable. Residual levels of organochlorine pesticides in vegetables from vegetable base of Nanjing suburb were also analyzed. As a result, nine representative organochlorine pesticides were 100% detected in all ten vegetable samples,excepting for p, p＇-DDD and 8-HCH. DDT and HCH are the main residues in vegetables, accounting for 71.3% -74.9% and 25.1% 28.7% of organochlorine pesticides residues detected, respectively. Though the average levels of DDT and HCH were generally lower than the maximum residue limit （MRL） of national standard, it still be potentially dangerous to food quality and human health.