箭型固相微萃取技术与GCMSMS联用方法用于水中异味化合物的检测

SPME Arrow combined with GCMSMS for determination of odor compounds in water

箭型固相微萃取技术是近几年发展起来的一项新型样品前处理技术,灵敏度高,机械性能好,无需使用有机溶剂,利用该技术对生活饮用水中的异味物质进行富集,然后通过三重四极杆气质联用系统进行高通量筛查和定量分析.对萃取过程中的萃取温度、萃取时间、进样口解吸的深度等影响因素进行了优化.发现萃取头在进样口进行解吸时插入的深度对解吸速度和效率有显著的影响.采用优化的参数建立了57种异味物质的定量测定方法.方法验证结果显示,该方法灵敏度高,相比于传统的固相微萃取方法,检测限下降1个数量级;方法准确度高,所有化合物的线性良好,线性相关系数能达到0.99以上;方法重复性很好,实际水样加标水平10 ng·L^(−1),重复测定10次,所有化合物的RSD值均小于20%,90%以上的化合物RSD小于10%.该方法各项性能均满足生活饮用水异味物质的检测要求,并且用于实际水样加标检测,无基质干扰的情况.

A novel solid-phase microextraction(SPME Arrow)system has been recently employed for sample pretreatment.It is a solvent-free microextraction technique with high sensitivity and reliable mechanical properties.In this study,the odor substances in drinking water were enriched by SPME-Arrow,followed by high-throughput screening and quantitative analysis through gas chromatography-triple quadrupole mass spectrometry(GCMSMS).Parameters influencing the extraction process,such as desorption depth of injection port,extraction time and temperature were carefully optimized.It was found that the insertion depth of SPME-Arrow at the injection port had a significant impact on the desorption speed and efficiency.A quantitative method for the determination of 57 odor substances was established based on the optimized parameters.Results showed that,compared to the conventional SPME method,this method had better sensitivity and improved the detection limit by one order of magnitude.This method also showed high accuracy and good linearity for each analyte with the values of linear correlation coefficient higher than 0.99.Ten replicate analyses of actual drinking water samples with a final internal standard concentration of 10 ng·L^(−1)provided reproducible results on the basis of average relative standard deviation(RSD)values.The RSD values for 90%of the analytes were lower than 10%,meanwhile those of the rest were all lower than 20%.There exhibited no matrix interference in the detection of spiked actual water samples.In general,the novel method meets the requirements for the enrichment and detection of odor substances in drinking water.