Title | Determination and Characterization of Oxy-Naphthenic Acids in Oilfield Wastewater |
Authors | Wang, Beili Wan, Yi Gao, Yingxin Yang, Min Hu, Jianying |
Affiliation | Peking Univ, Coll Urban & Environm Sci, Lab Earth Surface Proc, Beijing 100871, Peoples R China. Chinese Acad Sci, Ecoenvironm Sci Res Ctr, State Key Lab Environm Aquat Chem, Beijing 100085, Peoples R China. Peking Univ, Coll Urban & Environm Sci, Beijing 100871, Peoples R China. |
Keywords | CHROMATOGRAPHY-MASS SPECTROMETRY SANDS PROCESS WATER NATURAL-WATERS SAMPLES MS WASTEWATERS PETROLEUM OZONATION MIXTURES TOXICITY |
Issue Date | 2013 |
Publisher | environmental science technology |
Citation | ENVIRONMENTAL SCIENCE & TECHNOLOGY.2013,47,(16),9545-9554. |
Abstract | Oxy-naphthenic acids (oxy-NM) are one of the major components of NA mixtures in wastewaters from petroleum industries. The limited available data indicated that oxy-NAs were considered as a potential marker for the degradation of NAs, and some oxy-NAs exhibited endocrine disrupting activities. However, the lack of information on the structures and occurrences of oxy-NAs in oilfield wastewaters limited the interpretations of the biotransformation pathways of NAs and structure-specific toxicity. A sensitive method for simultaneous determination of oxy-NAs together with NAs was developed by combining MAX extraction column and UPLC-ESI--QTOF-MS. The 2000-fold SPE preconcentration step was highly specific for acids and the prewash solvent greatly reduced matrix effects in the UPLC-ESI--QTOF-MS analysis, resulting in an increase in sensitivity down to detection limits in the ng/L range. To provide structural information within each oxy-NA isomer class, a new method was developed by derivatizing oxy-NAs with dansyl chloride by UPLC-ESI+-QTOF-MS. The molecular ion dansyl derivatives from the corresponding oxy-NAs and characteristic fragmentation ions, not detected before derivatization, were observed in the extracts of oilfield wastewater, providing evidence that O-3-NAs and O-4-NAs were mainly composed of OH-NAs and (OH)(2)-NAs, respectively. Semiquantification of oxy-NAs and NAs in various oilfield wastewaters revealed NAs, O-3-NAs, and O-4-NAs present at concentrations of 187-397, 44-146, and 40-108 mu g/L, respectively. Significantly different profiles of NA mixtures were observed in petroleum refinery wastewater and oil sands extraction water, but the profile of oxy-NAs was similar to NAs in different wastewaters suggesting the existence of biotransformation between NAs and oxy-NAs in the environment, and hydroxylation could be one of the major biotransformation pathways of NAs. |
URI | http://hdl.handle.net/20.500.11897/160602 |
ISSN | 0013-936X |
DOI | 10.1021/es401850h |
Indexed | SCI(E) EI PubMed |
Appears in Collections: | 城市与环境学院 地表过程分析与模拟教育部重点实验室 |