Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA.
Environ Sci Technol. 2010 Nov 1;44(21):8128-33. doi: 10.1021/es101698q.
The occurrence, source, and sink processes of N-nitrosodimethylamine (NDMA) have been explored by means of combined laboratory, field, and model studies. Observations have shown the occurrence of NDMA in fogs and clouds at substantial concentrations (7.5-397 ng L(-1)). Laboratory studies were conducted to investigate the formation of NDMA from nitrous acid and dimethylamine in the homogeneous aqueous phase. While NDMA was produced in the aqueous phase, the low yields (<1%) observed could not explain observational concentrations. Therefore gaseous formation of NDMA with partitioning to droplets likely dominates aqueous NDMA formation. Box-model calculations confirmed the predominant contributions from gas phase formation followed by partitioning into the cloud droplets. Measurements and model calculations showed that while NDMA is eventually photolyzed, it might persist in the atmosphere for hours after sunrise and before sunset since the photolysis in the aqueous phase might be much less efficient than in the gas phase.
通过实验室、现场和模型研究相结合的方式，探索了 N-亚硝基二甲胺（NDMA）的发生、来源和汇过程。观测结果表明，NDMA 大量存在于雾和云中（7.5-397ng/L）。实验室研究旨在探究亚硝酸和二甲胺在均相水相中的 NDMA 形成。尽管在水相中形成了 NDMA，但观察到的低产率（<1%）无法解释观测到的浓度。因此，气相形成 NDMA 并分配到液滴中可能是水相 NDMA 形成的主要方式。箱式模型计算证实，气相形成随后分配到云滴中的贡献占主导地位。测量和模型计算表明，尽管 NDMA 最终会被光解，但它可能会在日出后数小时和日落前数小时在大气中持续存在，因为水相中的光解可能比气相中的光解效率低得多。
