气相色谱-正化学源质谱法测定橡胶中N-亚硝胺及其前体物的迁移量

Determination of Migration Levels of N-Nitrosamines and N-Nitrosatable Substances from Balloons by Gas Chromatography Positive Chemical Ionization Mass Spectrometry

从样品前处理和仪器分析方法两方面对欧盟标准EN 12868:1999中N-亚硝胺及其前体物的测试方法进行了改进,使其更适合批量样品的快速精确分析。用人工唾液浸泡橡胶制品,模拟其接触人体过程中N-亚硝胺的析出过程,再用Sep-Pak AC2串联Sep-Pak Dry固相萃取小柱对人工唾液中的N-亚硝胺分析物进行萃取净化,最后用DB 624毛细管气相色谱柱对其进行分离,正化学源质谱在全扫和单扫两种模式下进行分析。7种N-亚硝胺在10～10000μg/L浓度范围内呈良好线性关系,相关系数R均大于0.99;对橡胶中N-亚硝胺及其前体物的方法检出限分别为1.25和5.00μg/kg,低于欧盟93/11/EEC的限量要求;3个加标水平1.25,12.5和125μg/kg的回收率分别为80.6%～95.5%,86.8%～98.3%和92.2%～110.4%,RSD分别为4.2%～7.7%,4.1%～5.8%和2.6%～4.3%(n=6)。分析的气球样品中,7种N-亚硝胺及其前体物的总检出含量分别为0.421～0.820 mg/kg和3.616～8.437 mg/kg,均超出欧盟93/11/EEC指令的限制要求;但分析的婴儿奶嘴样品中则均未有检出N-亚硝胺及其前体物。

For analysis of a bunch of samples,a rapid,selective,sensitive and precision method in EN 12868：1999 was developed to determine the release of N-nitrosamines and N-nitrosatable substances from elastomer or rubber teats and soothers in both of sample preparation and instrumental analysis.To imitate the migration of N-nitrosamines and N-nitrosatable substances from rubber balloons and teats to human body,rubber products studied in this research were soaked in artificial saliva.The target analytes released to artificial saliva were extracted by Sep-Pak AC2 connected to Sep-Pak Dry cartridges,and isolated by DB 624 GC column,and determined by positive chemical ionization mass spectrometry in both full scan and SIM mode.Linear concentration-response relationships were obtained in a calibration range from 10 to 1000 μg/L with high correlation（R0.99） for all target analytes.The method detection limits of each N-nitrosamines and N-nitrosatable substances released from rubber products were 1.25 and 5.00 μg/kg,respectively,which are much lower than the requirement of Directive 93/11/EEC（N-nitrosamines： 10 μg/kg;N-nitrosatable substances： 100 μg/kg）.The average spike recoveries ranged from 80.6% to 95.5%（RSD 4.2%-7.7%,n =6）,from 86.8% to 98.3%（RSD 4.1%-5.8%,n=6）,and from 92.2% to 110.4%（RSD 2.6%-4.3%,n=6） for the spiked levels of 1.25,12.5 and 125 μg/kg,respectively.The total concentrations of seven N-nitrosamines and N-nitrosatable substances in analyzed balloon samples ranged from 0.421 mg/kg to 0.820 mg/kg and from 3.616 mg/kg to 8.437 mg/kg,respectively,which did not comply with the requirement of Directive 93/11/EEC.However,all N-nitrosamines and N-nitrosa-table substances were not detected in analyzed teats and soothers samples.