吹扫捕集／气相色谱－质谱法测定水中挥发性有机物的质量控制研究

影响吹扫捕集／气相色谱－质谱法测定水中挥发性有机物的因素很多，如空气中的挥发性有机物可能通过采样瓶的扩散，使准确性和可靠性降低。结合环境监测工作实际，按分流比20∶1分流进样，选择11＃捕集阱，样品解析时选择解析时间0．5 min，选择吹扫管支座温度为40℃，选择与目标化合物相比相对保留时间在0．8～1．20之间内标物，同时样品采集、保存、运输和器皿清洗等条件严格按照国标方法进行，可以确保吹扫捕集／气相色谱－质谱法测定的精密度和准确度。

Quality Control in Determination of Volatile Organic Compounds in Water by Gas Chromatography Mass Spectrometry with Purge and Trap Sampling

There are many influence factors when determining volatile organic compounds in water by gas chromatography mass spectrometry with purge and trap sampling .For example, volatile organic compounds in air may contaminate the water sam-ple.In the process of transportation, the compounds in laboratory or purge gas and capture the impurities will produce interfer-ence, will lower the accuracy and reliability.Combined with the practice of environmental monitoring, Shunt 20:1 into the sam-ple, Choice No.11 trap, When the sample is resolved, the time 0.5 min is selected, and the temperature of the tube support is 40, and the relative retention time between 0.8-1.20 and the target compound is selected.At the same time, the sample collec-tion, preservation, transportation and the cleaning condition of the vessel is carried out strictly according to the national standard method to ensure better precision and accuracy.