偶氮胂Ⅲ褪色光度法测定土壤中的铬

王蓉; 张丽萍; 邹时英

偶氮胂Ⅲ褪色光度法测定土壤中的铬

1.
四川理工学院材料与化学工程学院, 四川自贡 643000
2.
四川理工学院材料与化学工程学院, 四川自贡 643000
3.
四川理工学院材料与化学工程学院, 四川自贡 643000

基金项目:

广州市教育系统首批建设创新学术团队项目资助

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出版历程
- 收稿日期: 2010-04-11
- 修回日期: 2010-08-02

Determination of Chromium in Soil Samples by Arsenazo Ⅲ Fading Spectrophotometry

1.
Material and Chemical Engineering Department, Sichuan University of Science and Engineering, Zigong 643000, China
2.
Material and Chemical Engineering Department, Sichuan University of Science and Engineering, Zigong 643000, China
3.
Material and Chemical Engineering Department, Sichuan University of Science and Engineering, Zigong 643000, China

摘要

摘要: 偶氮胂Ⅲ是一种稀土显色剂,利用Cr(Ⅵ)的氧化性使偶氮类试剂褪色而建立的褪色光度法测定铬是目前的研究热点之一。文章基于在硝酸介质中,偶氮胂Ⅲ与Cr(Ⅵ)发生灵敏的褪色反应,建立了褪色光度法测定土壤中铬的方法。褪色体系△A的最大吸收波长为545 nm,摩尔吸光系数为4.67×10⁴ L/(mol·cm),Cr(Ⅵ)的质量浓度在0~0.8 μg/mL内符合比耳定律。建立的方法用于土壤中痕量铬的测定,测定值与原子吸收光谱法结果一致,6次测定的相对标准偏差(RSD)小于3.1%,方法回收率为98.6％~102.6％。方法精密度好,准确度高。
- 铬 /
- 土壤 /
- 褪色光度法 /
- 偶氮胂Ⅲ
Abstract: In the nitric acid solution, chromium(Ⅵ) reacts with arsenazo Ⅲ to produce a sensitive color-fading reaction. Based on this fact, a discoloring spectrophotometric method was developed to determine chromium (Ⅵ) in soil. The maximum determination wavelength of the discoloration system is 545 nm with the molar absorption coefficient of 4.67×10⁴ L/(mol·cm). The measured data accorded with Beer's law when the chromium (Ⅵ) concentration was lower from 0 to 0.8 μg/mL. The method was used in the determination of chromium in soil samples, and the relative standard deviation (RSD) is less than 3.1% (n=6). The obtained results by fading spectrophotometry were in good agreement with those by atomic absorption spectrometry.
- chromium /
- soil /
- fading /
- spectrophotometry