Multi-wavelength spectrophotometric determination of Cr(VI) in water with ABTS
Multi-wavelength spectrophotometric determination of Cr(VI) in water with ABTS
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DOI：
10.1016/j.chemosphere.2016.11.153
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发表时间：
2017-03-01
期刊：
影响因子：
8.8
通讯作者：
Guan, Xiaohong
中科院分区：
文献类型：
--
作者：
Fan, Wenjuan;Qiao, Junlian;Guan, Xiaohong
基于Cr（VI）与2，2 '-连氮双（3-乙基苯并噻唑啉-6-磺酸盐）（ABTS）的显色反应，建立了测定0.025-8.00 mg/L Cr（VI）的新方法。无色ABTS与Cr（VI）在强酸性条件（[H+] = 3.0或6.0 M）下反应，产生稳定的有色自由基ABTS（中心点+），其可在415、649或732 nm下通过荧光光度法测量。ABTS在这三个波长处的吸光度增加（中心点+）生成均为线性（小于1.0%偏差），并且在415、649或732 nm处，添加的Cr（VI）的灵敏度分别为1.099 × 10（5）、3.720 × 10（4）和4.150 × 10（4）M-1 cm（-1），分别该方法可定量检测低于饮用水排放标准0.025 mg/L的Cr（VI），定性检测0.002 mg/L的Cr（VI）。在415 nm处测得生成的ABTS（中心点+）的摩尔吸光系数为（3.69 +/- 0.01）x 10（4）M-1 cm（-1），Cr（VI）与ABTS之间的反应具有1：3的化学计量因子，超过ABTS。发现所产生的ABTS（中心点+）的吸光度在去离子水或废水中稳定，并且可以准确地测定废水中的Cr（VI）。ABTS法对Co（II）离子也有良好的抗干扰性能。ABTS法可用于Cr（VI）-S（IV）体系中Cr（VI）的测定。(C)2016爱思唯尔有限公司版权所有
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(center dot+), which could be measured spectrophotometrically at 415, 649 or 732 nm. The absorbance increase at these three wavelengths for ABTS(center dot+) generation were all linear (less than 1.0% deviation) with respect to the amount of added Cr(VI) and the sensitivity were 1.099 x 10(5), 3.720 x 10(4), and 4.150 x 10(4) M-1 cm(-1) 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(center dot+) generated was determined to be (3.69 +/- 0.01) x 10(4) M-1 cm(-1) 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(center dot+) 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. (C) 2016 Elsevier Ltd. All rights reserved.