SBSE-TDS-GC-MS快速测定茶叶中拟除虫菊酯类农药残留  

Rapid Determination of Pyrethroid Pesticide Residues in Tea by Stir Bar Sorptive Extraction-Thermal Desorption-Gas Chromatography-Mass Spectrometry

作　　者：杨蕾[1] 王保兴 侯英 徐济仓 杨燕 杨勇 

机构地区：[1]云南瑞升烟草技术(集团)有限公司

出　　处：《食品科学》2007年第11期435-439,共5页Food Science

摘　　要：采用固相萃取搅拌棒(SBSE)萃取茶叶中的拟除虫菊酯类农药,再用热脱附-气质联用仪分析。研究了萃取时间、不同浓度甲醇、不同浓度NaCl对萃取效率的影响;对热脱附温度、时间及冷阱收集温度等条件进行了优化。实验结果表明,SBSE-TDS-GC-MS方法对菊酯类农残的萃取回收率在92.8%～116.65%之间,相关系数≥0.9961;检测限为2.82～10.79μg/kg;方法RSD=11%(n=6)。用此方法测定了市售红茶(滇红)和乌龙茶(铁观音)中的菊酯类农药残留,其残留量低于茶叶中MRL。A novel and fast method for determination of pyrethroid pesticide residues in tea samples was established. The samples from the market were ultrasonic extracted by methanol before analysis with stir bar sorptive extraction-thermal desorption system-gas chromatography-mass spectrometry （SBSE-TDS-GC-MS）. Polydimethylsioxane （PDMS） was used as extraction phase. The effects of extraction time, methanol addition and salting out on extraction efficiency were studied. The optimized conditions consist of a 10% methanol addition extracted with stir bars at 1100 r/min during lh at ambient temperature. Desorption was carried out at 300℃ during 4 rain under a helium flow of 50 ml/min in the splitless mode while maintained a cryoforming temperature of 0℃ in the programmed-temperature vaporization （PTV） injector of the GC-MS system. Under these described conditions, the detection limits of pyrethroid pesticides in tea sample are in the range of 2.36 ～ 12.60 ng/kg, and recoveries of the method are in the range of 91.50% ～ 116.58%. The correlation coefficient of pyrethroid pesticides in tea samples is≥ 0.9961. And the repeatability （n=6） of the method is less than 11% relative standard deviation （RSD）. Pyrethroid pesticide residues in real life samples （red tea and oolong） can be determined rapidly by this method.

关 键 词：固相萃取搅拌棒 热脱附 拟除虫菊酯类 气质联用仪 茶叶 

分 类 号：TS207.53[轻工技术与工程—食品科学]