固相萃取-气相色谱-质谱法测定化妆品中的硝基甲烷

建立了测定化妆品中硝基甲烷的固相萃取-气相色谱-质谱分析方法。膏霜、水剂、散粉、香波、唇膏等不同类型的化妆品样品加入甲醇或无水乙醇超声提取后,提取液高速离心处理,浓缩上清液,采用Sep-Pak Silica固相萃取柱净化,收集80%甲醇-20%二氯甲烷洗脱液,浓缩后经无水硫酸钠脱水,进行气相色谱-质谱定性及定量分析。选用HP-INNOWax石英毛细管柱(30m×0.25mm×0.25μm),程序升温,流速1.0mL/min;采用电子轰击电离源,选择监测离子(m/z30、46、61,其中61为定量离子),外标法定量。方法的平均回收率为83.0%～96.4%,相对标准偏差(RSD)为1.0%～5.3%,方法对硝基甲烷的检出限为0.2mg/kg。该方法准确、灵敏度高,可用于化妆品中硝基甲烷的测定。

Determination of Nitromethane in Cosmetics by Solid Phase Extraction-Gas Chromatography-Mass Spectrometry

A method of solid phase extraction-gas chromatography-mass spectrometry was developed for the determination of nitromethane in cosmetic samples.The cream,lotion,powder,shampoo and lipstick samples were ultrasonically extracted with methanol or ethanol,and centrifuged.Then the concentrated supernatant was purified with a Sep-Pak Silica solid phase extraction cartridge with 80% methanol-20% dichloromethane as eluent.The eluent was further dehydrated and then analyzed with a HP-INNOWax capillary column(30 m × 0.25 mm × 0.25 μm) under electron ionization conditions at a flow rate of 1.0 mL/min.The quantitation was performed by the external standard method under selected ion monitoring mode(SIM) by monitoring ions of m/z30,46,61.The recoveies were 83.0%~96.4%,with the relative standard deviations(RSD) of 1.0%~5.3%.The detection limit was 0.2 mg/kg.The proposed method was proved to be accurate and stable,which was applicable for the determination of nitromethane in cosmetics.