CORRESPONDENCE/REBUTTAL pubs.acs.org/est
Response to Comment on “Identification of Monochloro- nonabromodiphenyl Ethers in the Air and Soil Samples from South China”
W
e thank La Guardia and coauthors for their comments on our recent paper describing the identification of monochlorononabromodiphenyl ethers (Cl-nonaBDEs) in air and soil samples from South China. We apologize for not citing their study1 in our paper. We used mixed chlorinated/brominated diphenyl ethers (chlorinated/ brominated dioxins and chlorinated/brominated biphenyls were widely used for mixed halogenated compounds in previous studies),2,3 60 -chloro-2, 20 , 3,30 , 4,40 , 5,50 , 6-nonabromodiphenyl ether (60 -Cl-BDE-206), 50 -chloro-2, 20 , 3,30 , 4,40 , 5,6,60 -nonabromodiphenyl ether (50 -Cl-BDE-207), and 40 -chloro-2, 20 , 3,30 , 4,5,50 , 6,60 -nonabromodiphenyl ether (40 -Cl-BDE-208) as keywords for the literature search. Regrettably, La Guardia0 s study was missed in our retrieval. In fact, La Guardia et al. tentatively identified two ClnonaBDEs based on the fragment characteristics of mass spectra in one of four sludges investigated in 2010.1 The dominant fragment ions in their study were similar to those observed in the synthesized standards4 and actual environmental samples in our study.5 La Guardia et al. did not agree with our hypothesis that ClnonaBDEs might be formed during the manufacture of PBDE and chlorine-containing products (e.g., PVC). In addition, they assumed that Cl-nonaBDEs were impurities in the Albemarle Corporation product. They further cited the details of an Albemarle Corporation Deca-BDE patent as support. We agree with this assumption that Cl-nonaBDEs might be byproduct of BDE-209 manufacturing. However, we tested our hypothesis based on the following experiments: (1) we investigated seven commercial decabromodiphenyl ether (BDE-209) products obtained from Chinese chemical markets and found no Cl-nonaBDEs; (2) we collected soil samples from near PBDEs manufacturing plants in Weifang City and found no Cl-nonaBDEs in any of the soil samples; (3) we personally contacted other Chinese scholars who also conducted soil PBDEs research in Weifang City6 and did not find Cl-nonaBDEs based on the retention times of higher brominated diphenyl ethers and ClnonaBDEs; (4) we found Cl-nonaBDEs in two pooled black plastics, including cover, shell and wire. We actually have a great deal of interest in the formation mechanism of Cl-nonaBDEs because the limited literatures regarding Cl-nonaBDEs in environmental media exhibited discrepant results. In 2006, Christiansson et al. investigated the occurrence of 40 -Cl-BDE-208 in environmental samples; however, they did not find any and used it as internal standard for determination of higher brominated BDEs.7,8 La Guardia et al. only detected Cl-nonaBDEs in the 2008 sludge sample, but not in samples collected earlier (20022007), even though they all contained considerable amounts of BDE-209.1 In our study, we detected Cl-nonaBDEs in outdoor and indoor samples in Guangzhou City collected between October 2004 and April 2005.5 Obviously, the observation in Guangzhou air samples could not be explained by impurities of the Albemarle r 2011 American Chemical Society
Corporation product, because most of the BDE-209 used in China are believed to have been produced domestically. Therefore, further study not only need investigate the environmental occurrence of Cl-nonaBDEs, but also clarify the different formation mechanisms of Cl-nonaBDEs. Zhiqiang Yu,†,* Kewen Zheng,‡ Guofa Ren,‡ Shengtao Ma,†,§ Pingan Peng,† Guoying Sheng,† and Jiamo Fu†,‡ †
State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment Protection and Resource Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China ‡ Institute of Environmental Pollution and Health, School of Environment and Chemical Engineering, Shanghai University, Shanghai 200072, China § Graduate School of the Chinese Academy of Sciences, Beijing 100039, China
’ AUTHOR INFORMATION Corresponding Author
*E-mail:
[email protected].
’ REFERENCES (1) La Guardia, M. J.; Hale, R. C.; Harvey, E.; Chen, D. Flameretardants and other organohalogens detected in sewage sludge by electron capture negative ion mass spectrometry. Environ. Sci. Technol. 2010, 44, 4658–4664. (2) Du, B.; Zheng, M.; Huang, Y.; Liu, A.; Tian, H.; Li, L.; Li, N.; Ba, T.; Li, Y.; Dong, S.; Liu, W.; Su, G. Mixed polybrominated/chlorinated dibenzo-p-dioxins and dibenzofurans in stack gas emissions from industrial thermal processes. Environ. Sci. Technol. 2010, 44, 5818–5823. (3) Ohta, S.; Tokusawa, H.; Nakao, T.; Aozasa, O.; Miyata, H.; Alaee, M. Global contamination of coplanar polybrominated/chlorinated biphenyls (Co-PXBs) in the market fishes from Japan. Chemosphere 2008, 73, S31–38. (4) 2,20 ,3,30 ,4,5,50 ,6,60 -nonabromo-40 -chlorodiphenyl ethers. The Science behind wellington Laboratories. 2009. http://www.well-labs. com/pages/learn.html (accessed June 10, 2011). (5) Yu, Z.; Zheng, K.; Ren, G.; Wang, D.; Ma, S.; Peng, P.; Wu, M.; Sheng, G.; Fu, J. Identification of monochloro-nonabromodiphenyl ethers in the air and soil samples from South China. Environ. Sci. Technol. 2011, 45, 2619–2625. (6) Jin, J.; Wang, Y.; Liu, W.; Yang, C.; Hu, J.; Cui, J. Polybrominated diphenyl ethers in atmosphere and soil of a production area in China: Levels and partitioning. J. Environ. Sci. (China) 2011, 23, 427–33. (7) Christiansson, A.; Teclechiel, D.; Eriksson, J.; Bergman, A.; Marsh, G. Methods for synthesis of nonabromodiphenyl ethers and a chloro-nonabromodiphenyl ether. Chemosphere 2006, 63, 562–569. (8) Eljarrat, E.; Marsh, G.; Labandeira, A.; Barcelo, D. Effect of sewage sludges contaminated with polybrominated diphenyl ethers on agricultural soils. Chemosphere 2008, 71, 1079–1086. Published: June 14, 2011 6708
dx.doi.org/10.1021/es201982k | Environ. Sci. Technol. 2011, 45, 6708–6708
