活性铬在线分离富集-流动注射-光度法测定铬的研究

Study on the On-line Separation and Determination of Cr in Flow Injection Spectrophotometry with a Microcolumn of Activated Alumina

在浓度为0.5mmol/L,流速为2.26mL/min的HNO_3截流下,以活性Al_2O_3微型柱在线分离工业废水中的Cr(Ⅲ)和Cr(Ⅳ),吸附的Cr(Ⅳ)用0.1mol/LNH_3 H_2O从柱上洗脱,用分光光度法测定。将试样经碱性KMnO_4法氧化处理后,在相同条件和系统中测定总铬,用差减法得到Cr(Ⅲ)含量。本法分析速度为36样/h,回收率100％～110％,相对标准偏差为0.8％(2mg/L)和5.3％(0.1mg/L)。

A rapid and sensitive method for using a microcolumn of activated alumina in FIA manifold to separate and preconcntration Cr(Ⅵ) from Cr(Ⅲ) in the sample of industrial waste water and to determine with sepctrophotometric detection has been developed.The total Cr was determinated under same conditions after the sample was treated with basic KMnO4,and the concentration of Cr(Ⅲ) was finally obtained by taking a difference.The sampling rate was 36 samples/h,the range of the recoveries was 100% ~ 200% and the relative standard deviation at 2 and 0.1mg/L were 0.8 and 5.3%,respectively.