降低二硫化碳萃取液中痕量苯检出下限的气相色谱法

A Gas Chromatographic Method to Decrease the Detection Limit of Trace Benzene in CS-2 Extract

提出一个直接进样口（岛津ＷＢＩ－１７）和ＳＥ－３０填充柱测定海水中微量苯的二硫化碳萃取气相色谱分析方法。方法的检测下限低、操作简单、样品用量少、重复性好。

A method to decrease the detection limit of trace benzene in CS\-2 extract from coastal water by gas chromatography has been studied. A direct injection port (Shimadzu WBI\|17) and a 2 m×2 mm i.d. column packed with Chromosorb W(AW\|DMCS) coated with 10%SE\|30 was used. It is simpler and has low detection limit, small sample amount and high repeatability. The experiment showed that the trace water in the organic phase and the too small purge flow of the direct injection port could cause serious tailing of CS\-2 peak. There was an optimum value of the purge flow (purge flow/total flow=5%). The minimum detectable limit of benzene was 4 μg/L. The repeatability ( RSD ) was better than 6% and the average recovery was 96.7% .