摘要
用气相色谱方法研究了吸附剂对大气有机物的富集特性，提出用吸附参数泄漏体积ＢＴＶ（最大采样体积）以及脱附参数最低脱附温度或最小吹扫体积作为富集指标的新思想，并用冲洗色谱法测定了一些有机物在ＧＤＸ－３０１上的特性参数。不同温度的特性参数由１ｏｇ（ＢＴＶ）与１／Ｔｃ的线性关系外推得到。实验表明，所研究的２０种有机物（除了甲醇外）在装有２ｇＧＤＸ－３０１的采样管和０．１４ｇＧＤＸ－３０１的聚焦管上的最大采样体积分别不小于０．８Ｌ（３５℃）和０．３Ｌ（０℃）。在１８０℃脱附时所需的最小吹扫体积分别不大于１７７ｍＬ和１３ｍＬ，或者说吹扫体积分别为１８０ｍＬ和３０ｍＬ时的最低脱附温度分别不高于１８０℃和１５７℃。对于同系物或性质相近的有机物，富集参数与沸点之间存在线性关系，该沸点规律有助于本研究未测定的其它有机物富集参数的估算。
A gas chromatographic method for the measurement of enriching characters of adsorbents used in preconcentration of organic compounds from air samples was studied. The character parameters suggested in this study include adsorption parameters (breakthrough volume or maximum sample volume) and desorption ones (minimum flashing volume and the lowest desorption temperature). The parameters of some low molecular mass compounds such as alcohols, saturated hydrocarbons, aromatics, esters and halohydrocarbons on GDX 301 were measured by using elution GC method. The maximum sample volumes of all the 20 compounds (with exception of methanol) got from these experiments are not less than 0.8 L at 35℃ for sampling tube (filled with 2g GDX 301) and 0.3 L at 0℃ for focus tube (with 0.14g GDX 301). The corresponding minimum flashing volumes of less than 177mL and 13mL respectively are needed to complete desorption at 180℃, and the lowest desorption temperatures of not over 180℃ and 157℃ at flashing volume of 180mL and 30mL are lower than the maximum allowable operating temperature (250℃) of GDX 301. The results showed that GDX 301 is a good adsorbent for enrichment of the organic compounds mentioned above. The following operating conditions are recommended: using the above sampling tube and focus tube, actual sample volume ≤0.8L , adsorption temperature ≤35℃ and focus temperature 0℃, desorption for 6min from sampling tube and 1min from focus tube at 180℃ with flashing rate 30mL/min. Good correlations between the parameters and boiling point of the investigated compounds were found. It can be used to estimate the parameters of other organic compounds not measured in this study.
出处
《色谱》
CAS
CSCD
北大核心
1997年第4期274-277,共4页
Chinese Journal of Chromatography
基金
浙江省分析测试基金
关键词
气相色谱法
空气分析
有机物
吸附剂
富集
VOC
gas chromatography, adsorption enrichment, breakthrough volume, air analysis
