Söderstrom Gunilla, Sellström Ulla, de Wit Cynthia A, Tysklind Mats
Environmental Chemistry, Umeå University, SE-901 87 Umeå, Sweden.
Environ Sci Technol. 2004 Jan 1;38(1):127-32. doi: 10.1021/es034682c.
Polybrominated diphenyl ethers (PBDE) are commonly used flame retardants. During the past years, concerns have increased due to their occurrence in the environment and humans. In general, the concentrations of lower brominated (tetra-penta) diphenyl ethers in biota exceed those of the most heavily used product, decabromodiphenyl ether (DecaBDE). In this study, the photolytic debromination of DecaBDE has been investigated in order to study the formation of lower brominated diphenyl ethers. The time course of photolysis of DecaBDE was studied in toluene, on silica gel, sand, sediment and soil using artificial sunlight and on the natural matrices (sediment, soil, sand) also using natural sunlight. DecaBDE was photolytically labile and formed debromination products in all matrices studied. Nona- to tetraBDEs were formed as well as some PBDFs. The half-lives in toluene and on silica gel were less than 15 min, and half-lives on other matrices ranged between 40 and 200 h. No differences were seen in the debromination pattern of BDE congeners sequentially formed in the different matrices or under different light conditions. However, the debromination rates were strongly dependent on the matrix with longer half-lives on natural matrices than artificial ones.
多溴二苯醚（PBDE）是常用的阻燃剂。在过去几年中，由于其在环境和人类中的存在，人们对其的关注度不断提高。一般来说，生物群中低溴化（四溴 - 五溴）二苯醚的浓度超过了使用最广泛的产品十溴二苯醚（DecaBDE）的浓度。在本研究中，对DecaBDE的光解脱溴作用进行了研究，以探讨低溴化二苯醚的形成。使用人工阳光研究了DecaBDE在甲苯、硅胶、沙子、沉积物和土壤中的光解时间进程，同时也使用自然阳光研究了其在天然基质（沉积物、土壤、沙子）中的光解时间进程。DecaBDE在光解作用下不稳定，在所有研究的基质中均形成了脱溴产物。形成了九溴至四溴二苯醚以及一些多溴二苯并呋喃。在甲苯和硅胶上的半衰期小于15分钟，在其他基质上的半衰期在40至200小时之间。在不同基质中或不同光照条件下依次形成的BDE同系物的脱溴模式没有差异。然而，脱溴速率强烈依赖于基质，在天然基质上的半衰期比在人工基质上的长。
