Ren Dongxia, Sun Chengjun, Ma Guanqun, Yang Danni, Zhou Chen, Xie Jiayu, Li Yongxin
West China School of Public Health, Sichuan University, Chengdu 610041, China.
Provincial Key Laboratory for Food Safety Monitoring and Risk Assessment of Sichuan, Chengdu 610041, China.
Int J Anal Chem. 2018 Mar 8;2018:8426598. doi: 10.1155/2018/8426598. eCollection 2018.
A new method has been developed to simultaneously determine 7 pyrethroid residues in tea brew using gas chromatography-mass spectrometry (GC-MS) combined with solid phase microextraction (SPME) with multiwalled carbon nanotubes (MWCNTs) coated fiber. The MWCNTs coated fiber of SPME was homemade by using stainless steel wire as coating carrier and polyacrylonitrile (PAN) solution as adhesive glue. Under the optimized conditions, a good linearity was shown for bifenthrin, fenpropathrin, permethrin, and cyfluthrin in 1-50 ng mL and for cypermethrin, fenvalerate, and deltamethrin in 5-50 ng mL. The correlation coefficients were in the range of 0.9948-0.9999. The average recoveries of 7 pyrethroids were 94.2%-107.3% and the relative standard deviations (RSDs) were less than 15%. The detection limit of the method ranged from 0.12 to 1.65 ng mL. The tea brew samples made from some commercial tea samples were analyzed. Among them, bifenthrin, fenpropathrin, and permethrin were found. The results show that the method is rapid and sensitive and requires low organic reagent consumption, which can be well used for the detection of the pyrethroids in tea brew.
已开发出一种新方法，采用气相色谱 - 质谱联用（GC - MS）结合涂有多壁碳纳米管（MWCNTs）的固相微萃取（SPME）纤维，同时测定茶汤中的7种拟除虫菊酯残留。SPME的MWCNTs涂层纤维是以不锈钢丝为涂层载体、聚丙烯腈（PAN）溶液为粘结剂自制的。在优化条件下，联苯菊酯、甲氰菊酯、氯菊酯和氯氟氰菊酯在1 - 50 ng/mL范围内呈良好线性，氯氰菊酯、氰戊菊酯和溴氰菊酯在5 - 50 ng/mL范围内呈良好线性。相关系数在0.9948 - 0.9999之间。7种拟除虫菊酯的平均回收率为94.2% - 107.3%，相对标准偏差（RSDs）小于15%。该方法的检测限为0.12至1.65 ng/mL。对一些市售茶叶样品制成的茶汤样品进行了分析。其中，检测到了联苯菊酯、甲氰菊酯和氯菊酯。结果表明，该方法快速灵敏，有机试剂消耗低，可很好地用于茶汤中拟除虫菊酯的检测。
