分散液液微萃取-气相色谱-质谱法测定茶饮料中5种农药残留

Detrmination of Five Kinds of Pesticides Residue in Tea Beverages by Dispersive Liquid-Liquid Microextraction Combined with GC-MS

目的:建立分散液液微萃取-气相色谱-质谱法测定绿茶、红茶及花茶3类茶饮料中的噻嗪酮、联苯菊酯、氯菊酯、氯氰菊酯和氰戊菊酯5种农药残留的残留量。方法:以绿茶饮料为基质,考察了分散剂和萃取剂的种类和体积、萃取时间及萃取方式对回收率的影响,确定最优萃取条件为以1 mL乙腈为分散剂、100μL氯仿为萃取剂,并将其加入到5 mL的样品溶液中,手摇振荡萃取3 min。结果:5种农残在0.2~200μg/L浓度范围内线性关系良好,相关系数为0.9983~0.9998。检出限为0.04~1.94μg/kg,低、中、高三浓度回收率为95.0%~110.0%,相对标准偏差为1.5%~7.3%,5种农残的富集倍数为32~45。利用所建立方法对市售9种茶饮料进行了5种农残检测,均未检出农药残留。实际样品的加标回收率为61.9%~104%。结论:此法操作简单、快速、低耗高效、环境友好,可以为茶饮料中农残检测提供方法依据。

Objection:Determination of residual amounts of five pesticides(buprofezin,biphenthrin,permethrin,cypermethrin and fenvalerate)in three kinds of tea beverages(green tea,black tea and jasmine tea)by dispersive liquid-liquid microextraction combined with GC/MS.Methods:Taking the green tea for instance,factors that affect the pesticides recovery from extraction were evaluated,including the type and volume of dispersant and extractant,extraction time and the extraction method.An optimal extraction condition was determined as follows:1 mL of acetonitrile(dispertant)and 100μL of chloroform(extractant)were added into 5 mL of the sample solution with shaking and an extraction time of 3 min.Results:Well linear relationships were obtained for the five pesticides within the concentration range of 0.2~200μg/L,with correlation coefficient values of 0.9983~0.9998.The detection limits(LOD)based on signal to noise ratio of 3 ranged from 0.04 to 1.94μg/kg,the recovery rates ranged from 95.0%~110.0%at low,middle and high concentrations and the relative standard deviation(RSD)of 1.5%~7.3%.The enrichment factors ranged from 32 to 45.The as-established method was applied in detection of five pesticides in nine tea beverages,and none of them were detected,the recovery rates of actual samples ranged from 61.9%~104%.Conclusion:This method is simple,fast,cost-effective,efficient and environmentally friendly,which can give base for the detection of pesticides residue in tea beverages.