总铬全程空白污染来源分析及解决方案
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摘要
针对日常工作中发现分光光度法检测总铬的全程空白存在明显的铬检出问题,试验对超纯水、滤纸、硫酸、磷酸的铬本底排查结果显示,铬的主要污染来源为磷酸,3家生产商生产的磷酸均存在明显的铬污染,2家生产商生产硫酸并无明显铬污染。为进一步提高样品测试结果的准确度,需降低全程空白结果,提出只采用(1+1)硫酸消解样品,显色前再加入(1+1)磷酸的优化方案。该方案经高浓度Cr(Ⅲ)标准点样品及实际复杂基体样品检验,具有较好的方法精密度和准确度。
In view of the obvious problem of chromium pollution in the whole process blank of spectrophotometric determination of total chromium in daily work, the chromium background of ultrapure water, filter paper, sulphuric acid and phosphoric acid is investigated. The results show that the main source of chromium pollution is phosphoric acid. There is obvious chromium pollution in phosphoric acid produced by three producers, and there is no obvious chromium pollution in sulphuric acid produced by two producers. In order to further improve the accuracy of the sample results, it is necessary to reduce the blank results of the whole process. An optimum scheme is proposed that only(1+1) sulfuric acid is used to digest the sample and(1+1) phosphoric acid is added before color development. The scheme has been tested by high concentration trivalent chromium standard point samples and practical complex matrix samples, and has good precision and accuracy of the method.
In view of the obvious problem of chromium pollution in the whole process blank of spectrophotometric determination of total chromium in daily work, the chromium background of ultrapure water, filter paper, sulphuric acid and phosphoric acid is investigated. The results show that the main source of chromium pollution is phosphoric acid. There is obvious chromium pollution in phosphoric acid produced by three producers, and there is no obvious chromium pollution in sulphuric acid produced by two producers. In order to further improve the accuracy of the sample results, it is necessary to reduce the blank results of the whole process. An optimum scheme is proposed that only(1+1) sulfuric acid is used to digest the sample and(1+1) phosphoric acid is added before color development. The scheme has been tested by high concentration trivalent chromium standard point samples and practical complex matrix samples, and has good precision and accuracy of the method.
引文
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[4]李敏,吴翠琴,聂颖,等.人体血清中邻苯二甲酸酯高背景干扰因素去除研究[J].广州大学学报(自然科学版),2018,17(3):45-49.
[5]齐文启,尤洋,林燕春,等.环境保护验收重金属污染与监测中的问题[J].现代科学仪器,2012,29(2):145-148.
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[2]邢志贤,侯冬利,牛利民,等.土壤中邻苯二甲酸酯类检测空白研究[J].中国环境监测,2009,25(1):44-46.
[3]皮仙宏.测定土壤中酞酸酯类有机物时空白干扰的排除:2011中国环境科学学会学术年会论文集(第四卷)[C].北京:中国环境科学学会,2011:387-391.
[4]李敏,吴翠琴,聂颖,等.人体血清中邻苯二甲酸酯高背景干扰因素去除研究[J].广州大学学报(自然科学版),2018,17(3):45-49.
[5]齐文启,尤洋,林燕春,等.环境保护验收重金属污染与监测中的问题[J].现代科学仪器,2012,29(2):145-148.
[6]高菊芬.污水监测过程的质量控制[J].化学分析计量,2003,12(6):37-38.
[7]赖永忠,王亮根.两种双波长法用于减小浊度对废水中六价铬测定结果的影响[J].化学工程师,2012,26(10):27-30,35.