液液萃取-气相色谱-串联质谱法测定水中三氯乙醛

Determination of chloral hydrate in water by using liquid-liquid extraction-gas chromatography-tandem mass spectrometry

目的考察提取溶剂种类、用量及时间、色谱、质谱条件四大因素对三氯乙醛在水中的提取和分析的影响。建立了三重四级杆气相色谱-质谱法(GC-MS/MS)对水中三氯乙醛直接快速分析方法。方法水样经用甲基叔丁基醚(MTBE)提取,无水硫酸钠除水,振荡,静置分层,取上清液,进行GC-MS一级全扫描,然后采用优化的GC-MS/MS“定时SRM”模式进行测定。结果三氯乙醛在0.5μg/L^50μg/L内具有较好的线性关系,线性相关系数可达0.9997,检出限为0.2μg/kg。在0.5μg/L、10μg/L、50μg/L 3个添加水平下,回收率为86.3%~98.9%,灵敏度高,重现性良好,相对标准偏差≤4%。结论方法前处理简单,准确度、精密度良好,适用于水中三氯乙醛的快速测定。同时该方法避免了国家标准方法中衍生化所存在的其他消毒副产物的干扰,避免气相色谱单独使用时的假阳性现象。

Objective To investigate the influence of extraction solvent types,dosage and time,chromatography,mass spectrometry conditions on the extraction and analysis of chloral hydrate in water.A direct and rapid analysis method for chloral hydrate in water by triple quadrupole gas chromatography-mass spectrometry(GC-MS/MS)was established.Methods Water samples were extracted with MTBE and dehydrated with anhydrous sodium sulfate,after shocking and still stratification,supernatant liquid was obtained for subsequent analysis.The parent ions of each synthetic cannabinoid were detected by running GC/MS in a full scan mode,and then were analyzed by GC-MS/MS with“timed SRM”mode.Results The results showed that the linear correlation coefficient can be over 0.9997 in the range of 0.5μg/l-50μg/l,the detection limit of chloral hydrate is 0.2μg/kg,the recovery rate is within 86.3%-98.9%,the sensitivity is high,the reproducibility is good,and the relative standard deviation is no more than 4%.Conclusion The method was simple,rapid and accurate.It can be used in detecting chloral hydrate in water.The method could avoid interactions of other disinfection by products compared to the method involving derivation and could also avoid false positive results in methods using GC alone.