固相萃取净化及超高效液相色谱-串联质谱法测定橡胶制品中的13种N-亚硝胺

建立了固相萃取(SPE)净化、超高效液相色谱-串联质谱(UHPLC-MS/MS)测定橡胶制品中13种N-亚硝胺的方法。样品于密闭萃取瓶中于60 ℃下用甲醇超声萃取30 min，C₁₈固相萃取小柱对萃取液进行净化，经C₁₈色谱柱分离，最后用电喷雾正离子(ESI⁺)和多重反应监测模式(MRM)对13种N-亚硝胺进行定性、定量测定。实验中对样品前处理、色谱分离条件和质谱检测条件进行了优化。在优化的实验条件下，橡胶样品中添加N-亚硝基二甲胺(NDMA)与N-亚硝基-二乙基胺(NDEA)为500 μg/kg、其他组分均为50 μg/kg时，各组分的相对标准偏差(RSD，n=7)小于10%；在实际样品中的加标回收率为70.7%~117.0%；方法的检出限(LOD，以10倍标准偏差计)为0.5~500 μg/kg。方法可应用于橡胶制品中13种N-亚硝胺的测定。

Determination of N-nitrosamines in rubber products by solid phase extraction purification and ultra high performance liquid chromatography-tandem mass spectrometry

A method using C₁₈ solid phase extraction (SPE) for purification and ultra high performance liquid chromatography (UHPLC) coupled with electrospray ionization tandem mass spectrometry (ESI-MS/MS) for detection was developed to simultaneously determine 13 N-nitrosamines in rubber products. The analytes were extracted with methanol (60 ℃, 30 min) with the aid of ultrasonic technique and then purified by a C₁₈ SPE cartridge. The analytes were separated on a C₁₈ chromatographic column and qualitatively and quantitatively detected by a mass spectrometer with positive ESI at multiple reaction monitoring (MRM) mode. The operating parameters for UHPLC separation and ESI-MS/MS detection were also optimized. Under optimum operating conditions, the relative standard deviations (RSDs, n=7) were less than 10% at spiked level of 50 μg/kg for all analytes except N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA) which were spiked at 500 μg/kg. The recoveries spiked in real samples were from 70.7% to 117.0%. The limits of detection (LODs, 10 times of standard deviation) were in the range of 0.5-500 μg/kg. The method has been successfully applied to the simultaneous determination of the 13 N-nitrosamines in rubber products.