固相萃取-气相色谱-质谱联用法同时测定地表水中的四乙基铅和联苯胺
刘慧杰,石金涛
上海城市水资源开发利用国家工程中心有限公司,上海 200082
Simultaneous determination of tetraethyl lead and benzidine in surface water with gas chromatography-mass spectrometry by using solid phase extraction
刘慧杰,石金涛
Shanghai National Engineering Research Center of Urban Water Resources Co., Ltd., Shanghai 200082, China
摘要:建立了固相萃取-气相色谱-质谱联用同时测定地表水中四乙基铅和联苯胺的方法。主要考察影响固相萃取的因素,包括固相萃取小柱的选择,水样pH值,以及洗脱溶剂对富集效果的影响。将水样调节至pH 12,经过HLB小柱富集、二氯甲烷洗脱后,采用DB-5MS柱程序升温分离,选择离子扫描模式,在10 min内完成两物质的测定。四乙基铅和联苯胺的质量浓度分别在20~200 μg/L和40~400 μg/L范围内与其色谱峰面积呈良好的线性关系,线性相关系数分别为0.9958和0.9939。在最佳条件下富集1000倍,四乙基铅和联苯胺的检出限分别为0.003 μg/L,0.008 μg/L。分别添加两浓度水平的四乙基铅和联苯胺到水样中,平均加标回收率为47.5%~89.4%,测定结果的相对标准偏差为5.4%-8.9%(n=6)。该方法简便、灵敏、快速,适合水源水中四乙基铅和联苯胺的常规检测。
Abstract:A gas chromatography mass spectrometry(GC-MS) method with solid phase extraction(SPE) was developed for the determination of tetraethyl lead and benzidine simultaneously in surface water. The factors affecting solid phase extraction were investigated, including solid phase extraction column, pH of water sample and the elution solution. pH of the water sample was adjusted to 12, then the water sample was concentrated by HLB extraction cartridge, and eluted with dichloromethane. The analytes were separated on a DB-5MS capillary column and detected by selected ion monitoring mode. The mass concentration of tetraethyl lead and benzidine was linear with the chromatographic peak area in the range of 20-200 μg/L and 40-400 μg/L, respectively, with the correlation coefficients of 0.9958 and 0.9939. The concentration was enriched 1000 times under the optimum conditions, and the detection limit of tetraethyl lead and benzidine was 0.003
μg/L and 0.008 μg/L, respectively. Mean recoveries of tetraethyl lead and benzidine from surface water samples ranged from 47.5%-89.4% for two different fortification levels, and the relative standard deviations of the determination results were 5.4%-8.9%(n=6). The method is simple, sensitive and efficient, which is suitable for routine analysis in surface water.
关键词:四乙基铅;联苯胺;固相萃取;气相色谱-质谱联用法;选择离子扫描;地表水
Keywords:tetraethyl lead; benzidine; solid phase extraction; gas chromatography-mass spectrometry; selected ion monitoring mode; surface water
本文引用格式:
刘慧杰,石金涛.固相萃取气质联用法同时测定地表水中的四乙基铅和联苯胺[J].化学分析计量,2018,27(3):57-60.
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