State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Guangzhou Key Laboratory of Environmental Exposure and Health, School of Environment, Jinan University, Guangzhou 510632, China.
Chemosphere. 2017 Mar;171:460-467. doi: 10.1016/j.chemosphere.2016.11.153. Epub 2016 Dec 1.
A new method for Cr(VI) (0.025-8.00 mg/L) determination based on the reaction of Cr(VI) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) in aqueous solutions was developed. The colorless ABTS reacted with Cr(VI) under strong acidic conditions ([H] = 3.0 or 6.0 M) producing a stable colored radical ABTS, which could be measured spectrophotometrically at 415, 649 or 732 nm. The absorbance increase at these three wavelengths for ABTS generation were all linear (less than 1.0% deviation) with respect to the amount of added Cr(VI) and the sensitivity were 1.099 × 10, 3.720 × 10, and 4.150 × 10 M cm of added Cr(VI) at 415, 649 or 732 nm, respectively. Cr(VI) of 0.025 mg/L below the discharge standard of drinking water could be detected with the method quantitatively and 0.002 mg/L Cr(VI) was determined qualitatively. The molar absorptivity of ABTS generated was determined to be (3.69 ± 0.01) × 10 M cm at 415 nm and the reaction between Cr(VI) and ABTS had a stoichiometric factor of 1:3 in excess of ABTS. The absorbance of generated ABTS was found to be stable in deionized water or wastewater and Cr(VI) spiked in wastewater could be determined accurately. The ABTS method also had a good anti-interference performance against Co(II) ions. Moreover, the ABTS method could be successfully used in the Cr(VI)-S(IV) system for Cr(VI) determination.
一种基于 Cr(VI)与 2,2'-联氮基-双(3-乙基苯并噻唑啉-6-磺酸)（ABTS）在水溶液中的反应测定 Cr(VI)（0.025-8.00mg/L）的新方法被开发出来。在强酸条件下（[H] = 3.0 或 6.0M），无色的 ABTS 与 Cr(VI)反应生成稳定的有色自由基 ABTS，可在 415、649 或 732nm 处分光光度法测量。在这三个波长处，ABTS 生成的吸光度增加与加入的 Cr(VI)量呈线性关系（偏差小于 1.0%），灵敏度分别为 415nm 时 1.099×10、649nm 时 3.720×10 和 732nm 时 4.150×10Mcm 加入的 Cr(VI)。该方法可定量检测饮用水排放标准以下的 0.025mg/L 的 Cr(VI)，并可定性检测 0.002mg/L 的 Cr(VI)。ABTS 生成的摩尔吸光率在 415nm 时测定为（3.69±0.01）×10Mcm，Cr(VI)与 ABTS 之间的反应在 ABTS 过量时具有 1:3 的化学计量因子。生成的 ABTS 的吸光度在去离子水或废水中稳定，可准确测定废水中添加的 Cr(VI)。ABTS 法对 Co(II)离子也具有良好的抗干扰性能。此外，ABTS 法可成功用于 Cr(VI)-S(IV)体系中 Cr(VI)的测定。
