国标法测定水质硫化物方法优化  

Optimization of national standard method for determination of sulfide in water

作　　者：王少伟 张英红 张聪 郑峻峰 李妍 赵珮妮[2] WANG Shaowei;ZHANG Yinghong;ZHANG Cong;ZHENG Junfeng;LI Yan;ZHAO Peini(Yantai Ecological Environment Monitoring Center of Shandong Province,Yantai 264000,China;School of Chemistry and Chemical Engineering,University of Jinan,Jinan 250022,China)

机构地区：[1]山东省烟台生态环境监测中心,山东烟台264000 [2]济南大学化学化工学院,济南250022

出　　处：《化学分析计量》2022年第9期6-11,共6页Chemical Analysis And Meterage

基　　金：国家自然科学青年基金(22006048)。

摘　　要：针对《水质硫化物的测定 亚甲基蓝分光光度法》(HJ 1226—2021),研究了光照和显色液对硫化物测定的影响,提出了快速测定法。硫化物与N,N-二甲基对苯二胺和硫酸铁铵显色反应不受光照影响,N,N-二甲基对苯二胺硫酸溶液使用量由10 mL减少为7 mL,将分步加入N,N-二甲基对苯二胺和硫酸铁铵溶液方式改为加入混合显色液;改变了显色液配制方式,以浓磷酸代替浓硫酸配制N,N-二甲基对苯二胺磷酸溶液,使用30 mm光程比色皿将高、低浓度校准曲线整合,硫化物的质量浓度在0.02~0.40 mg/L范围内与吸光度的线性关系良好,相关系数为0.999 2;样品加标回收率为72.0%~107%。与国标法测定结果进行对比,样品加标回收率由63.9%提升至72.5%和75.2%,加标样品测定结果的相对标准偏差由15.7%降至11.9%和9.11%(n=6)。优化后的方法具有良好的回收率和精密度,简化了校准曲线和样品分析过程,适用于水质中硫化物的测定。According to “water quality determination of sulfide–methylene blue spectrophotometric method” (HJ 1226—2021),the influence of illumination and chromogenic reagent on the determination of sulfide were investigated,and a fast-detecting method was proposed.The color reaction of sulfide with N,N-dimethyl p-phenyleneamine and ammonium ferric sulfate solution was not affected by illumination.The usage of N,N-dimethyl p-phenylenediamine sulfuric acid solution was reduced from 10 mL to 7 mL,and the method of gradually adding N,N-dimethyl p-phenylenediamine and ammonium ferric sulfate was changed to adding mixed chromogenic solution.The method of preparing chromogenic reagent solution was changed in which phosphoric acid instead of sulfuric acid was used to prepare N,N-dimethyl p-phenylenediamine phosphoric acid solution.Using N,N-dimethyl p-phenylenediamine phosphoric acid solution chromogenic reagents,the calibration curves of high and low concentrations were integrated with a 30 mm optical path cuvette,and the linearity of sulfide concentration was good in the range of 0.02–0.40 mg/L,and the correlation coefficient was 0.999 2.The recoveries of sulfide by the proposed fast-detecting method were 72.0%–107%.Compared with the results determined by the national standard method,the recovery rate of spiked samples increased from 63.9% to 72.5% and 75.2%,and the relative standard deviation of spiked samples decreased from 15.7% to 11.9% and 9.11%(n=6).The improved methods show good recovery and precision,simplify calibration curves and sample analysis process,which is suitable for the determination of sulfide in water quality.

关 键 词：硫化物 亚甲基蓝分光光度法 显色液 快速测定法 

分 类 号：O657.3[理学—分析化学]