工作场所空气中二乙基甲酮活性炭采集溶剂解吸气相色谱测定方法的研究

Investigation of Gas Chromatographic Determination Method of Diethyl Ketone in the Air of Workplace Using Activated Charcoal Sampling and Solvent Desorption

[目的]建立可定量测定工作场所空气中二乙基甲酮(DEK)的实用方法。[方法]气态的DEK用活性炭(AC)管吸附后,以二硫化碳(CS_2)溶剂解吸,最后由气相色谱[GC(FID)]分离并测定。[结果]统计分析显示DEK色谱峰面积(y)与DEK浓度(x)呈线性相关,其回归方程为(?)=11.3+15.5x(n=6),相关系数r>0.9999;当DEK浓度在625～5000μg/ml时,定量测定结果的相对标准偏差(RSD)为2.7%～6.1%;该方法的检出限为33μg/ml(进样1.0μl);平均解吸效率达81.9%;穿透容量(BTV)>24mg(100mg活性炭);使用已吸附DEK 2439μg含100mg活性炭管并密闭放置5d,下降率为9.0%;采样效率达100%。[结论]该气相色谱定量法可用于工作场所空气中气态DEK的浓度测定。

[ Objective ] To establish a precticable method for quantifying of diethyl ketone（ DEK ）in the air of workplace. [ Methods ] Gaseous DEK was adsorbed with activated charcoal （AC）tube, then desorbed with a solvent of carbon disulfide （ CS2 ）, and finally separated and analyzed by gas chromatography [ GC （ FID ） ]. [ Results ] Statistic analysis showed that the peak area of the DEK chromatogra（y ）correlated significantly and linearly with DEK concentration（ x ）, indicated by y=-11.3＋15.5 x（ n=6 ）and r〉0.999 9. The relative standard deviation （ RSD ）for the quantitfying was between 2.7% and 6.1% when the DEK concentrations in the range between 625 and 5 000 μg/ml. The method had a detection limit of 33 μg/ml （ injection for 1.0 μl ）. The average desorption efficiency reached 81.9% and the breakthrough volume （ BTV ）was more than 24 mg （ 100mg AC ）. Using 100mg-containing AC tube that had absorbed 2 439 μg of the DEK and closed stored for 5 days, the decay rate was 9.0%. The sampling efficiency was perfective, attaining 100%. [ Conclusion ] Results above indicate this quantitative GC method might be applied in the detection of gaseous DEK in the air of workplace.