采用塑胶等饰材在运动场地广泛应用,但其内含的游离甲苯-2,4二异氰酸酯可能释放出来导致运动场上空气的严重污染。国际卫生组织严格规定异氰酸酯聚合物中游离单体含量必须控制在0.5%以下。本实验用注射器直接抽取待测场地的空气,采用直接进样电喷雾萃取电离源(EESI)串联质谱进行检测。工作条件为:离子源电压3kV;质谱仪毛细管电压21V;毛细管温度175℃。本方法无需样品前处理,操作简单,1S内就能完成单个样品的测定,无干扰,检出限低于0.04%(S/N=100,n=5);测量的精密度(RSD)为1.4%(n=8)。结合实验结果,讨论了解温度光照,通风条件、垂直高度等环境因素对空气中甲苯-2,4-二异氰酸酯含量的影响。
Plastic materials are widely used for sports venues, which release free toluene-2,4-diisocyanate (TDI), resulting in severe air pollution. The content of the free TDI monomer in the isocyanate-polymer is rigorously regulated by WHO to be lower than 0.5%. In this study, ambient air samples containing trace a- mounts of TDI-water aerosols were sucked with glass syringes on the spot and then directly injected into the home-made extractive electrospray ionization(EESI) source, which was installed on an LTQ-MS instrument for direct analysis of samples with complex matrices. The experimental condtionsconditions were: electrospray voltage, 3 kV ;capillary voltage,21 V ; capillary temperature, 175 ~C. The raw samples were directly analyzed by tandem EESI-MS without any sample pre-treatment and a single sample analysis was completed within 1 s. The limit of detection was found to be less than 0.04% ( n = 5, S/N = 100) , which is much lower than that al- lowed in air. Based to the experimental results, the effects of several environmental factors such as tempera- ture, illumination of sun, air ventilation and altitude on the TDI contents are discussed.