连续流动分析法测定水中硫化物的显色剂配制方法研究

Preparation of Chromogenic Reagent for Determining Sulfide in Water Using Continuous Flow Analysis

针对连续流动分析法测定水中硫化物方法中显色剂N,N-二甲基-1,4苯二胺二盐酸盐保质期短的问题,研究了不同体积比盐酸或硫酸介质对延长显色剂保质期的影响,确定了延长保质期的试剂配制方法,并对该方法的适用性进行了检验。结果显示,体积比10%硫酸介质的显色剂优于盐酸介质显色剂,可以存放一周。使用此显色剂进行硫化物分析检出限为0.003 mg/L,线性范围0.000 mg/L^2.00 mg/L,平行测定相对偏差0.0%~11.8%,加标回收率82.0%~102%,可以满足环境样品分析需求。

In order to prolong the shelf time of chromogenic reagent N,N - dimethylbenzene - 1,4 - diamine dihydrochloride （ DMPP ~ 2HC1）used for sulfide determination by SKALAR SAN ~ ~ continuous flow analyzer, different volume ratio of hydrochlo- ric acid or sulphuric acid was added to the chromogenic reagent to explore the best method for prolonging the shelf time of DMPP ~ 2HC1. The applicability of the method to environmental water samples was also assessed. The resuhs showed that chromogenic reagent with 10% sulphuric acid could be stored for one week, while the chromogenic reagent with hydrochloric acid should be used immediately. The detection limit of chromogenic reagent with 10% sulphuric acid for sulfide determination was 0. 003mg/L with linear range from 0. 000 to 2. 00 mg/L（r =0. 999 9）and relative deviation of parallel samples from 0. 0% to 11.8%. The re- covery of standard addition of the method ranged from 82.0% to 102%, which can meet the requirements of environmental water sample monitoring.