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目的建立茶叶中溴虫腈、啶虫脒和茚虫威3种农药残留的气相色谱-质谱测定方法,并对60份深圳市售茶叶进行调查。方法茶叶用乙腈提取,提取液浓缩后经CARB/NH2固相萃取柱净化,用气相色谱-质谱联用法(GC-MS),外标法同时定量测定溴虫腈、啶虫脒和茚虫威。结果本方法溴虫腈、啶虫脒和茚虫威的线性范围为50~1 000μg/L,线性相关系数在0.999 1~0.999 9之间,检出限为0.02 mg/kg,平均加标回收率82.2~108.2%之间,相对标准偏差(RSD)在0.7~7.3%之间。60份茶叶样品检出率35%,溴虫腈含量为0.044~0.126 mg/kg,啶虫脒含量为0.055~0.171 mg/kg,茚虫威含量为0.031~0.079 mg/kg。结论该方法准确可靠,灵敏度高,能满足同时定量检测茶叶中溴虫腈、啶虫脒和茚虫威。
Objective To establish a method for the determination of 3 pesticide residues of chlorfenapyr, acetamiprid and indoxacarb in tea by gas chromatography-mass spectrometry (GC-MS) and investigate 60 commercial tea leaves in Shenzhen. Methods The tea leaves were extracted with acetonitrile. The extracts were concentrated and purified by CARB / NH2 solid phase extraction (SPE) column. The contents of chlorfenapyr, acetamiprid and indoxacarb were simultaneously determined by gas chromatography-mass spectrometry (GC-MS) . Results The linear range of chlorfenapyr, acetamiprid and indoxacarb was 50-1 000 μg / L with the linear correlation coefficient of 0.999 1-0.9999 9 and the limit of detection was 0.02 mg / kg. The average spike recoveries Rates ranged from 82.2 to 108.2% with relative standard deviations (RSDs) between 0.7 and 7.3%. The detection rate of 60 tea samples was 35%, the content of chlorfenapyr was 0.044 ~ 0.126 mg / kg, the content of acetamiprid was 0.055 ~ 0.171 mg / kg and the content of indoxacarb was 0.031 ~ 0.079 mg / kg. Conclusion The method is accurate, reliable and sensitive. It can simultaneously detect chlorfenapyr, acetamiprid and indoxacarb in tea simultaneously.