比较了测定油藏地层水和土壤这类复杂基质中3种甜菜碱型表面活性剂的样品净化方法.选用直接过微孔滤膜、活性炭固相萃取柱、碱性氧化铝固相萃取柱、HLB固相萃取柱、MCX固相萃取柱、WCX固相萃取柱,对10、50、100 mg/L质量浓度下的回收率对比分析,并结合高效液相色谱-质谱联用全扫描质谱图甄选较优净化手段.分析结果显示,采用混合型强阳离子交换柱(MCX固相萃取柱)进行净化提取后,用高效液相色谱-质谱联用法进行检测,3种甜菜碱型表面活性剂在质量浓度10~50 mg/L内与色谱峰面积线性良好,相关系数均达到0.99以上,检出限为0.01 mg/L.加标回收率为96.9%~100.5%,相对标准偏差为0.7%~2.1%(n=7).该方法操作简单,特异性强,作为复杂基质中甜菜碱型表面活性剂净化最佳方法,为甜菜碱型表面活性剂的检测提供坚实的基础.
The different purification method was tested and compared for extracting 3 betaine surfactants from reservoir formation water and soil.Direct microporous filtration membrane,activated carbon solid-phase extraction column,alkaline alumina solid-phase extraction column,HLB solid-phase extraction column,MCX solid-phase extraction column,and WCX solid-phase extraction column were selected to conduct comparative analysis of recovery rates at mass concentrations of 0.01,0.05,0.1 mg/mL,and the optimal purification method was determined by combining full scan mass spectrometry.The results showed that after purification and extraction using MCX(mixed strong cation exchange column)solid-phase extraction column,the detection was performed using high-performance liquid chromatography mass spectrometry.The linearity was good in the range of 10-50 mg/L,and the correlation coefficients were all above 0.99,with a detection limit of 0.01 mg/L.The recoveries rate of spiking were 96.9%-100.5%with the relative standard deviations of 0.7%-2.1%(n=7).This method is simple to operate,and it has strong specificity,which can provide a reference for the detection of betaine type surfactants.