工作场所空气中石油醚的气相色谱测定方法研究

Determination of airborne petroleum ether at workplace by gas chromatography

目的建立工作场所空气中石油醚的气相色谱测定方法。方法活性炭吸附空气中石油醚,热解析后气相色谱(FID)测定。结果空气中石油醚浓度在102～407 mg/m^3时,相对标准偏差为0.20%～0.80%(n=6);回归方程y=-9396 +56450 x,相关系数r=0.9999;检出限为1.2×10^(-2)μg/ml(进样1 ml);平均解析效率为94.4%;穿透容量(BTV)为8.04 mg/100 mg;低温放置7 d,回收率90.1%;采样效率100%。结论本方法适用于工作场所空气中石油醚的浓度测定。

Objective To study the sampling and measurement of airborne petroleum ether in the air at workplace. Methods The charcoal tube was use as adsorptive material and petroleum ether was separated from charcoal with thermal desorption and determined by GC with liD. Results The RSD in the range of 102 - 407 mg/m^3 was 0.20% - 0.80%（n = 6） and the regression formula was y = -9396＋56450 x,r = 0.9999. Determination limit was 1.2 × 10^-2 μg/ml （injection for 1.0 ml）. The average desorption efficiency was 93.8% -95.0 %. Breakthrough volume （BTV） was 8.04 mg in a tube containing 100 mg absorption charcoal and 608 μg of petroleum ether can be adsorbed. The petroleum ether can still remain stable with a recovery rate of 90.1% when adsorbed tube was kept at 4℃ in tightly closed condition for 7 days. The sampling efficiency is 100%. Conclusion This method is applicable to determine airborne petroleum ether at workplace.