测定工作场所空气中一甲胺、二甲胺的顶空气相色谱法

Determination of monomethylamine and dimethylamine in the air of workplace by headspace gas chromatography

目的建立工作场所空气中一甲胺,二甲胺的顶空气相色谱测定方法。方法酸性吸收液采集空气中的一甲胺、二甲胺,碱溶液中和后顶空进样气相色谱,经CP-Volamine毛细管色谱柱分离,氢焰离子化检测器测定。结果一甲胺浓度范围为11.70～93.54μg/ml时,标准曲线回归方程为Y=0.458 1X-1.034 5(r=0.999 0);二甲胺浓度范围为10.59～84.74μg/ml时,标准曲线的回归方程为Y=0.864 5X-2.206(r=0.999 1)。一甲胺方法检出限为1.65μg/ml,最低检出浓度为0.55 mg/m3(以采集15 L空气样品计);二甲胺检出限为1.54μg/ml,最低检出浓度为0.32 mg/m3(以采集24 L空气样品计)。样品于4℃冰箱内可稳定保存5 d。结论该方法可同时测定工作场所空气中一甲胺和二甲胺浓度。

[ Objective ] To establish a determination method of methylamine, dimethylamine in workplace air by gas chromatogra- phy. [ Methods ] Methylamine and dimethylamine were collected in acid liquid, neutralized by alkali solution and separated in the capillary column CPVolamine by headspace gas chromatography, using the hydrogen flame ionization detector. [ Results ] Concen- tration range of methylamine was 11.70 to 93.54 μg/ml, the standard curve regression equation was Y = 0. 4581X-1. 034 5 （r=0.999 0） Concentration range of dimethylamine was 10.59 to 84.74 μg/ml, the standard curve regression equation was Y = 0. 864 5X-2. 206 （ r = 0. 999 1 ）. The detection limit of methylamine was 1.65 μg/ml, the minimum detectable concentration 0.55 mg/m3 （ calculation with 15 L） ; The detection limit of dimethylamine was 1.54μg/ml, the minimum detectable concentration was 0.32 mg/m3 （ calculation with 24 L） Samples could be stored at 4℃ refrigerator for 5 days. [ Conclusion] The method is satis- fied with the simultaneous determination of concentration of methylamine and dimethylamine in workplace air.