Abstract：
Volatile methyl siloxanes (VMS) are ubiquitous in indoor environments due to their use in personal care products. This paper builds on previous work identifying sources of VMS by synthesizing time-resolved proton-transfer reaction time-of-flight mass spectrometer VMS concentration measurements from four multiweek indoor air campaigns to elucidate emission sources and removal processes. Temporal patterns of VMS emissions display both continuous and episodic behavior, with the relative importance varying among species. We find that the cyclic siloxane D5 is consistently the most abundant VMS species, mainly attributable to personal care product use. Two other cyclic siloxanes, D3 and D4, are emitted from oven and personal care product use, with continuous sources also apparent. Two linear siloxanes, L4 and L5, are also emitted from personal care product use, with apparent additional continuous sources. We report measurements for three other organosilicon compounds found in personal care products. The primary air removal pathway of the species examined in this paper is ventilation to the outdoors, which has implications for atmospheric chemistry. The net removal rate is slower for linear siloxanes, which persist for days indoors after episodic release events. This work highlights the diversity in sources of organosilicon species and their persistence indoors.
摘要：
挥发性甲基硅氧烷(VMS)由于其在个人护理产品中的用途而在室内环境中普遍存在。本文建立在先前的工作基础上，通过合成时间分辨质子转移反应飞行时间质谱仪VMS浓度测量值，从四个多星期的室内空气运动中确定VMS的来源，以阐明排放源和去除过程。VMS排放的时间模式既显示出连续行为，也显示出周期性行为，物种之间的相对重要性不同。我们发现环状硅氧烷D5始终是最丰富的VMS物种，主要归因于个人护理产品的使用。另外两种环状硅氧烷，D3和D4，从烤箱和个人护理产品使用中发出，连续来源也很明显。两种直链硅氧烷，L4和L5也是个人护理产品使用中发出的，具有明显的额外连续来源。我们报告了在个人护理产品中发现的其他三种有机硅化合物的测量结果。本文研究的物种的主要空气去除途径是向室外通风，这对大气化学有影响。直链硅氧烷的净去除率较慢，在发生释放事件后在室内持续数天。这项工作强调了有机硅物种来源的多样性及其在室内的持久性。
