新型冷阱气态挥发性有机物采样器在环境监测中的应用  

Application of a new cold trap sampler volatile organic compounds in environmental monitoring

作　　者：李佳 张晓旭 曹阳 谭丽[3] 陈勇 张夏 谢翔 LI Jia;ZHANG Xiaoxu;CAO Yang;TAN Li;CHEN Yong;ZHANG Xia;XIE Xiang(Chengdu Ecological Environmental Monitoring Center of Sichuan Provincial,Chengdu 610066,China;Sichuan Provincial Ecological Environmental Monitoring Center,Chengdu 610000,China;China National Environmental Monitoring Centre,Beijing 100012,China)

机构地区：[1]四川省成都生态环境监测中心站,四川成都610066 [2]四川省生态环境监测总站,四川成都610000 [3]中国环境监测总站,北京100012

出　　处：《中国测试》2022年第10期85-93,共9页China Measurement & Test

摘　　要：为解决固相吸附-热脱法同时测定挥发性有机物物质种类少、线性范围窄、液体标样与实际样品基体不一致,以及高湿样品水浴除水死体积大等问题,本研究采用新型冷阱气态挥发性有机物采样器结合热脱附-气相色谱质谱仪分析了气体中114种挥发性有机物。结果表明:在-10~40℃区间内,采样器设置流量为20.0~200 mL/min时,其流量误差≤0.1 mL/min。在20℃常温环境中采集0.01~0.83 nmol低浓度样品时,114种目标物r2范围为0.992~0.999 9,RSD范围为0.5%~23.8%;而-10℃采样温度下采集0.17~66.7 nmol高浓度样品,目标物r2范围为0.995~0.999 9,RSD范围为0.7%~23.5%。与35℃采样温度相比,-10℃低温采集时目标物线性浓度范围可有效扩大56%~400%。另外,采样器采用冷阱脱水管的方式可有效消除水分干扰,114种目标物中除乙醛、乙醇和1,4-二噁烷外,其余目标物的回收率为70.3%~117.8%。本研究为气体中挥发性有机物的监测提供新的技术支撑,在实际监测工作中具有重要的实用意义。In this paper, 114 gaseous volatile organic compounds(VOCs) were analyzed by thermal desorption-gas chromatography-mass spectrometrymtheod(GC-MS) with the use of a new cold trap gas sampler, which effectively solved the shortcomings of current method, such asthe few kinds of substances that can be simultaneously determined, the narrow linear range, the inconsistency between liquid standard and actual sample, and the large dead volume of water bath. Experiments showed that, sampling flow rateerroralways less than 0.1mL/min when the sampling temperature and flow rate were in –10-40 ℃ and 20.0-200 mL/min range,respectively. The linear correlation coefficient(r2) and relative standard deviation(RSD) for low concentration samples(0.01-0.83 nmol, sampling at 20 ℃) were 0.992-0.999 9 and 0.5%-23.8%, and which were 0.995~0.999 9and 0.7%-23.5% for high concentration samples(0.17-66.7 nmol, sampling at –10 ℃). When the sampling temperature decreased from 35-10 ℃, the effective linear concentration range of target VOCs were increased by 56%-400%. In addition, the sampler can effectively eliminate moisture interference by adopting cold trap dehydration tube, the recovery rate of 114 VOCs were 70.3%-117.8%, except for acetaldehyde, ethanol and 1,4-dioxane. This paper provides a new technical support for the monitoring of volatile organic compounds in gas and has important practical significance in the actual monitoring work.

关 键 词：新型冷阱气体采样器 挥发性有机物 热脱附 吸附剂 

分 类 号：X734.2[环境科学与工程—环境工程]