JOURNAL OF SEPARATION SCIENCE
·
2016
·Vol. 39
·期 11
·2146-2155
·
IF 2.741
Xiuzhi Bai,Ting Zhang,Haipu Li,Zhaoguang Yang
Chloroanisoles, particularly 2,4,6-trichloroanisole, are commonly identified as major taste and odor compounds in water. In the present study, a simple and efficient method was established for the simultaneous determination of chloroanisoles and the precursor 2,4,6-trichlorophenol in water by using low-density-solvent-based simultaneous dispersive liquid–liquid microextraction and derivatization followed by gas chromatography with electron capture detection. 2,4-Dichloroanisole, 2,6-dichloroanisole, 2,4,6-trichloroanisole, 2,3,4-trichloroanisole, and 2,3,6-trichloroanisole were the chloroanisoles evaluated. Several important parameters of the extraction-derivatization procedures, including the types and volumes of extraction solvent and disperser solvent, concentrations of derivatization agent and base, salt addition, extraction-derivatization time, and temperature were optimized. Under the optimized conditions (80 μL of isooctane as extraction solvent, 500 μL of methanol as disperser solvent, 60 μL of acetic anhydride as derivatization agent, 0.75% of Na 2 CO 3 addition w/v, extraction-derivatization temperature of 25°C, without salt addition), a good linearity of the calibration curve was observed by the square of correlation coefficients ( R 2 ) ranging from 0.9936 to 0.9992. Repeatability and reproducibility of the method were < 4.5% and <7.3%, respectively. Recovery rates ranged from 85.2 to 101.4%, and limits of detection ranged from 3.0 to 8.7 ng/L. The proposed method was applied successfully for the determination of chloroanisoles and 2,4,6-trichlorophenol in water samples.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 10
·7483-7502
·
IF 3.442
Wu Minrong,Ma Yongwen,Wan Jinquan,Wang Yan,Guan Zeyu,Yan Zhicheng
The nZVI@mesoSiO 2 nanocomposites with ordered mesoporous structure were successfully prepared through a novel two-step method. Influences of the different conditions on the physicochemical properties and catalytic behavior were investigated. Degradation of 2,4,6-trichlorophenol (2,4,6-TCP) under different conditions was evaluated, and the possible activation mechanism was speculated. The results indicate that only the definite increase in the molar ratio of CTAB/NaOH (cetyltrimethylammonium bromide/sodium hydroxide) helps to obtain the higher specific surface area and narrower pore size distribution of the nZVI@mesoSiO 2 . The thickness of this silica coating could be easily regulated by changing the dosage of the TEOS (tetraethylorthosilicate) precursor. High dosage of the TEOS (larger than 5 mL) leads to the formation of core-free silica particles and low catalytic activity, while nZVI@mesoSiO 2 cannot fully develop at a low dosage (2.5 mL). By controlling different extraction conditions, the nanoscale zero-valent iron core (nZVI) in the composite can be well preserved and corrosion resistant in the whole synthesis process. In this case, the as-prepared nanocomposites offer a high surface area of 638.78 m 2 g −1 as well as a large accessible pore volume of 0.49 cm 3 g −1 for the degradation, which contributing to a fast and efficient degradation of 2,4,6-TCP from aqueous solutions at an appropriate pH (pH 5.0). Moreover, the reusability investigation indicated that the nZVI cores will be inactivated and the pore will be blocked after repeated cyclic reactions. This comprehensive information provides not only a great understanding of the regulation mechanism of core–shell mesoporous nanocomposites, but also a further useful modification of the composites with high selectivity for 2,4,6-TCP.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）