Anal. Chem. 2001, 73, 3506-3510
Analysis of Oxidative Degradation Products of 2,4,6-Trichlorophenol Treated with Air Ions Huimin Ma,*,† Jens Wohlers,‡ Uwe Meierhenrich,‡ Axel Bernecker,‡ Vera Suling,‡ and Wolfram Thiemann*,‡
Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China, and Department of Chemistry, University of Bremen, D-28334 Bremen, Germany
The analysis of oxidative degradation products of 2,4,6trichlorophenol (TCP) treated with air ions, which are generated by electric discharge, is reported. Due to the complex nature of the degradation products, a combination of different detection techniques was employed to characterize them. The oxidative degradation of TCP is usually dependent on the treating approaches, and in this system, a stepwise degradation, beginning with the formation of a major product 2,6-dichloro-1,4-benzenediol as well as other minor ones (e.g., 3,5-dichlorocatechol) via substitution, is first proposed through a detailed analysis of GC/MS, etc., though some chromogenic quinones can transiently be present. Furthermore, high dechlorination (53%) was observed for TCP after a 60-min treatment, indicating that air ions can serve as an efficient dechlorination means. As a result of its widespread use in industry and agriculture,1,2 2,4,6-trichlorophenol (TCP) has become one of the most important pollutants in the environment (aqueous systems and soils). Furthermore, TCP is persistent, and polychlorinated dibenzo-pdioxins and dibenzofurans have also been found in chlorophenolcontaminated soils.3,4 Therefore, the removal of TCP from the environment and its chemical behavior have attracted much attention.5-11 Schmitzer and co-workers2 reported the mass balance of [14C]TCP and its conversion products in soil after 6 months under * Corresponding authors. H.M.: (e-mail)
[email protected]; (fax) +86-10-62559373. W.T.: (e-mail)
[email protected]. † Center for Molecular Sciences. ‡ University of Bremen. (1) Wennrich, L.; Popp, P.; Mo ¨der, M. Anal. Chem. 2000, 72, 546. (2) Schmitzer, J.; Bin, C.; Scheunert, I.; Korte, F. Chemosphere 1989, 18, 2383. (3) Assmuth, T.; Vartiainen, T. Chemosphere 1994, 28, 971. (4) Schecter, A. Dioxins and Health; Plenum Press: New York, 1994. (5) Kra¨mer, A.; Angerer, J. Fresenius J. Anal. Chem. 1995, 351, 327. (6) Bartels, P.; Ebeling, E.; Kra¨mer, B.; Kruse, H.; Osius, N.; Vowinkel, K.; Wassermann, O.; Witten, J.; Zorn, C. Fresenius J. Anal. Chem. 1999, 365, 458. (7) Kiyohara, H.; Takizawa, N.; Uchiyama, T.; Ikarugi, H.; Nagao, K. J. Ferment. Bioeng. 1989, 67, 339. (8) Meunier, B.; Sorokin, A. Acc. Chem. Res. 1997, 30, 470. (9) Patnaik, P. Handbook of Environmental Analysis: Chemical Pollutants in Air, Water, Soil, and Solid Wastes; Lewis Publishers, CRC Press: Boca Raton, FL, 1997; pp 431-432. (10) Kontsas, H.; Rosenberg, C.; Pfa¨ffli, P.; Ja¨ppinen, P. Analyst 1995, 120, 1745. (11) Wada, M.; Kinoshita, S.; Itayama, Y.; Kuroda, N.; Nakashima, K. J. Chromatogr., B: Biomed. Sci. Appl. 1999, 721, 179.
3506 Analytical Chemistry, Vol. 73, No. 14, July 15, 2001
outdoor conditions. It was found that the main pathway of degradation is the formation of soil-bound residues, and the only detectable conversion products are 2,4,6-trichloroanisole and 2,4,6trichlorophenyl ethyl ether. The degradability of TCP was tested by bacterial population in soil.7 At concentrations of
