车间空气中呋喃和四氢呋喃的气相色谱测定法

Gas Chromatographic Determination of Furan and Tetrahydro uranin Workplace Air by Charcoal Tube Collection and Thermal Desorption

本文建立了用活性炭管采样,热解吸,气相色谱测定车间空气中呋喃和四氢呋喃浓度的方法。采用内装100mg活性炭的采样管,在0.5mg/m^3呋喃和300mg/m^3四氢呋喃,空气湿度为89％时,以0.1L/min速度采样,呋喃和四氢呋喃的穿透容量分别为2.64mg和9.36mg。在温度250℃,氮气流量1ml/s下,四种浓度水平的解吸效率均大于92％。样品于室温下在活性炭管中贮存一周无明显丢失。气相色谱测定呋喃和四氢呋喃的最低检测限分别为1.0×10^(-4)μg和2.3×10^(-3)μg(进1.0ml空气样品),变异系数小于5％。

This method is to draw a known volume of air through an absorption tube packed with activated charcoal(20～40 mesh)with the help of a 100ml glass syringe. The absorption tube is made of glass tube of 20cm×4.0mm i.d.. The samples collected on charcoal were then desorbed by heating the tube to 250℃ and flushed with nitrogen at a flow rate of 1 ml/s to remove the absorbed compounds. The desorption recoveries of several concentration levels were all above 92％. A known quantity of furan and tetrahydrofuran sampled was kept at room temperature for one week and then analyzed without significant loss. The method was found to have a coefficient of variation of 5％ and a limit of detection of 1.O×10^(-4)μg and 2.3×10^(-3)μg for furan and tetrahydrofuran respectively (1.0 ml air sample) .