气相色谱-电子轰击电离/正化学电离质谱法测定白菜和苹果中3种有机锡类农药残留  

Determination of three organotin pesticide residues in apples and cabbages by gas chromatography-electron impact/positive chemical ionization mass spectrometry

作　　者：蔡理胜 沈伟健[2] 王正萍[1] 张睿[2] 丁涛[2] 余可垚[2] 王红 张文俊 龚玉霞[2] 

机构地区：[1]南京理工大学,江苏南京210094 [2]江苏出入境检验检疫局,江苏南京210001

出　　处：《色谱》2017年第11期1177-1183,共7页Chinese Journal of Chromatography

基　　金：上海市长三角科技合作项目(15395810100)~~

摘　　要：分别采用电子轰击电离(EI)源和正化学电离(PCI)源两种离子源技术建立了气相色谱-质谱(GC-MS)同时测定白菜和苹果中苯丁锡、三苯锡和三环锡含量的方法,并对这两种方法进行了比较。样品经氢溴酸消解、丙酮-正己烷(1∶2,v/v)提取,四乙基硼化钠衍生后用Florisil固相萃取柱净化,分别在EI源和PCI源下以选择离子监测模式进行测定。结果表明,方法的检出限(S/N=3)分别为0.01~0.05 mg/kg(EI源)和0.01~0.02 mg/kg(PCI源),定量限(S/N=10)分别为0.03~0.16 mg/kg(EI源)和0.02~0.06 mg/kg(PCI源)。三苯锡、三环锡和苯丁锡分别在各自的线性范围内线性关系良好,相关系数(r^2)≥0.997。在50、100、200μg/kg 3个添加水平下,采用GC-EI/MS和GC-PCI/MS时,阴性样品中3种有机锡的平均回收率分别为59.24%~97.36%(苹果)、50.54%~94.54%(白菜)和65.38%~95.86%(苹果)、62.56%~90.44%(白菜),相对标准偏差(RSD)均不超过6.9%(n=6)。该方法简单、灵敏,PCI源的选择性优于EI源,两种方法可以相互结合提高检测结果的可靠性。A method for the simultaneous determination of fenbutatin oxide,triphenyltin and cyhexatin in apples and cabbages was developed by gas chromatography-mass spectrometry coupled with two different ionization techniques,electron impact （EI） ionization and positive chemical ionization （ PCI）. At first,the samples were digested by hydrobromic acid,and extracted by acetone-hexane （1 ： 2, v /v ） . The extracts were derivatized by sodium tetraethylbo- rate as the derivatization reagent,and cleaned up by the Florisil SPE columns. Finally,the samples were analyzed by GC-EI/MS and GC-PCI/MS in selected ion monitoring （SIM） mode. The results showed that good linearities were obtained with correlation coefficients （r2） greater than 0. 997 for fenbutatin oxide in the range of 75-500 pg/L in both foods,triphenyltin in the range of 50-1 000 pg/L in cabbages and 50-500 pg/L in apples and cyhexatin in the range of 50 - 1 000 pg/L in the two foods. The accuracy was checked at three spiked levels （50,100 and 200 pg/kg） in cabbages and apples. The limits of detection （LODs, S/N=3） were 0. 01-0. 05 mg/kg （EI） and 0. 01-0. 02 mg/kg （PCI）,and the limits of quantifications （LOQs, S/N=10）were 0. 03-0. 16 mg^kg （El） and 0. 02-0. 06 m^/kg （PCI）. The average recoveries ranged from 59. 24%-97. 36% （apples） and 50. 54%-94. 54% （cabbages） in the mode of El, and the corre-sponding values were 65. 38%-95. 86% and 62. 56%-90. 44% in the mode of PCI. The relative standard deviations （RSDs） were all less than 6. 9% （ n = 6）. The PCI method can be used to improve the accuracy in comparing with the EI, in terms of good selectivity and high sensitivity.

关 键 词：气相色谱-质谱 电子轰击电离源 正化学电离源 苯丁锡 三苯锡 三环锡 

分 类 号：O658[理学—分析化学]