通过对比填充不同吸附剂的不锈钢吸附管对10种醇类和醚类化合物的吸附能力,优化热脱附条件,考察不同色谱柱和样品保存时间对测定结果的影响,提出了热脱附-气相色谱-质谱法同时测定工作场所空气中10种醇类和醚类化合物含量的方法。用填装Tenax GR的吸附管采集气体样品,采集完成后将吸附管两端封好,设置一次热脱附温度为220℃,二次热脱附温度为240℃,吹扫时间为4 min,进样时间为50 s,在上述条件下进行热脱附,脱附的气体进入气相色谱仪,采用DB-624毛细管色谱柱分离目标物,并用配电子轰击离子源的质谱仪在选择离子监测模式下检测。结果显示:10种醇类和醚类化合物的质量在10~300 ng内与其对应的峰面积呈线性关系,检出限(3.143s)为0.5~1.9 ng;对空白样品进行3个浓度水平的加标回收试验,回收率为70.5%~125%,测定值的相对标准偏差(n=6)为1.0%~20%;方法用于实际样品分析,正丁醇、异丁醇和仲丁醇被检出,检出量依次为0.013,0.007,0.008 mg·m^-3。

By comparing the adsorption ability of stainless steel adsorption tubes filled with different adsorbents for 10 alcohol and ether compounds, optimizing the conditions of thermal desorption, investigating the effects of different chromatographic columns and the storage time of sample on the results of determination, a method for the simultaneous determination of 10 alcohol and ether compounds in air of workplace by gas chromatography-mass spectrometry after thermal desorption was proposed. The adsorption tube filled with Tenax GR was used to collect gas sample. After collection, both ends of the adsorption tube were sealed, and the thermal desorption was carried out under the following conditions:the first thermal desorption temperature of 220℃, the second thermal desorption temperature of 240℃, the purge time of 4 min, and the sample injection time of 50 s. The desorbed gas was entered into gas chromatograph, and the target compounds were separated on DB-624 capillary column and detected by mass spectrometer with electron impact ion source in selected ion monitoring mode. It was shown that linearity relationships between masses of 10 alcohol and ether compounds and their peak areas were kept in the range of 10-300 ng, with detection limits (3.143s) in the range of 0.5-1.9 ng. Test for recovery was made on the blank sample by standard addition method, giving results in the range of 70.5%-125%, and RSDs (n=6) of the determined values were ranged from 1.0% to 20%. This method was applied to analysis of the actual sample, n-butyl alcohol, isobutyl alcohol and sec-butyl alcohol were detected, with detection amounts of 0.013, 0.007, 0.008 mg·m^-3.