CSPS显色剂光度法测定微量钪的研究

采用氯代磺酚S作为显色剂，用分光光度法测定微量钪，探索了测定的实验条件，确定了以甲基橙为指示荆，乙酸钠调节溶液pH值，乙酸-乙酸钠缓冲溶液将pH值控刺在4～4．5，测定波长λ=646nm。结果表明：Sc（Ⅲ）的质量浓度在0～0．25mg·L-1，吸光度曲线符合朗伯比尔定律，回归方程为A=-3．2248Cs。（Ⅲ）＋0．0221，相关系数R2=0．9997，表观摩尔吸光系数ε=1．22×10^5。钪的加标回收率为97：4％～102．8％，RSD在2io％～3．0％。该方法简单易行，选择性和灵敏度较高，适合微量钪的快速测定。

Study on Photometric Determination of Trace Scandium with Chromogenic Reagent CSPS

In the paper, the trace Se（Ⅲ）was determined by means of spectrophotometric method taking the chlorosulphonphenol S as chromogenic reagent. During determination, the authors used methyl orange as indicator to adjust the pH with sodium acetate （NaAc）, keep the pH within 4 to 4.5 with buffer solution of acetic acid-sodium acetate （HAc-NaAc）, detecting the spectrophotometer at 2 = 646 nm. Results show that the Lambert Beer rule is effective in the range of 0-0.25 mg·L-1 , and the regression equation is A=3. 231 8Csc（Ⅲ）＋0. 020 9, R2 = 0. 999 6, the apparent molar absorptivity （ε） is 1.22 ×10^4. The addition standard recovery of scandium is 97.4M-102.8M and relative standard deviation（RSD） is 2%-3%. This detecting method is suitable for rapid determination of trace scandium.