连续流动分析法测定生活饮用水中的耗氧量
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摘要
目的建立以酸性高锰酸钾为氧化剂的连续流动分析法测定生活饮用水中耗氧量COD_(Mn)。方法以草酸钠为标准溶液,以含0.015 mol/L的高锰酸钾和5.0%硫酸混合溶液为载流,水样与载流混合后,在恒定温度93℃下,反应10 min,以最大吸收波长520 nm处测定未反应的高锰酸钾溶液吸光度,消耗的高锰酸钾的量与水样中的耗氧量COD_(Mn)呈线性相关。结果该法最低检出限为0.10 mg/L,耗氧量COD_(Mn)浓度在0.20 mg/L～6.00 mg/L,r=0.999 8,线性关系良好。该方法加标回收率为97.3%～108.4%,相对标准偏差(RSD)为0.82%～1.91%,该法与GB/T 5750.7—2006国家标准方法检测COD_(Mn)差异无统计学意义,同时该法氯化物抗干扰的上限达到800 mg/L,具有更好的抗氯化物干扰能力。结论该法操作简便、试剂和试样用量少、能耗低,精密度高、重现性好,可快速、准确、批量地测定生活饮用水中耗氧量。
Objective To establish a method for the determination of chemical oxygen demand COD_(Mn) in drinking water by continuous flow analysis(CFA) using acidic potassium permanganate as oxidant. Methods With sodium oxalate as standard solution for COD_(Mn) determination, and the mixed solution of 0.015 mol/L potassium permanganate and 5.0% sulfuric acid as current carrying fluid, the sample was reacted at 93°C for 10 mins and then the absorbance was measured at 520 nm, which was the maximum absorption wavelength of unreactive potassium permanganate. The consumption of potassium permanganate was linearly related with the COD_(Mn) in the water sample. Results The minimum detection limit of the method was 0.10 mg/L. The COD_(Mn) was linearly related with permanganate in the range of 0.20 mg/L-6.00 mg/L, and the correlation coefficient(r) was 0.999 8. The recovery rate of the method was within 97.3%-108.4% and the relative standard deviation(RSD) was within 0.82%-1.91%. There was no significant difference between this method and the National standard method of GB/T5750.7-2006 in the determination of COD_(Mn). And the upper limit of the anti-interference of chlorides reached to 800 mg/L in the method, which had better ability in avoiding the interference of chlorides. Conclusion The method is simple in operation, low in reagent and sample dosage, low in energy consumption, high in precision and good in reproducibility, which can quickly, accurately and quantitatively determine CODMn in drinking water.
Objective To establish a method for the determination of chemical oxygen demand COD_(Mn) in drinking water by continuous flow analysis(CFA) using acidic potassium permanganate as oxidant. Methods With sodium oxalate as standard solution for COD_(Mn) determination, and the mixed solution of 0.015 mol/L potassium permanganate and 5.0% sulfuric acid as current carrying fluid, the sample was reacted at 93°C for 10 mins and then the absorbance was measured at 520 nm, which was the maximum absorption wavelength of unreactive potassium permanganate. The consumption of potassium permanganate was linearly related with the COD_(Mn) in the water sample. Results The minimum detection limit of the method was 0.10 mg/L. The COD_(Mn) was linearly related with permanganate in the range of 0.20 mg/L-6.00 mg/L, and the correlation coefficient(r) was 0.999 8. The recovery rate of the method was within 97.3%-108.4% and the relative standard deviation(RSD) was within 0.82%-1.91%. There was no significant difference between this method and the National standard method of GB/T5750.7-2006 in the determination of COD_(Mn). And the upper limit of the anti-interference of chlorides reached to 800 mg/L in the method, which had better ability in avoiding the interference of chlorides. Conclusion The method is simple in operation, low in reagent and sample dosage, low in energy consumption, high in precision and good in reproducibility, which can quickly, accurately and quantitatively determine CODMn in drinking water.
引文
[1] 中华人民共和国卫生部.GB/T 5750.6—2006 生活饮用水标准检验方法有机物综合指标[S].北京:中国标准出版社,2006.
[2] 姜建芳,闫芳,曲恒永.对水中耗氧量及包装材料中高锰酸钾消耗量实验的几点建议[J].中国卫生检验杂志,2008,18(3):569-569.
[3] 徐陆妹,楼冰冰,章春锋.生活饮用水中耗氧量检测不确定度的评定[J].中国卫生检验杂志,2008,18(1):161-163.
[4] 廖丽,汪洋,于露露,等.水质理化检验综合实验-地表水高锰酸盐指数的测定[J].中国卫生检验杂志,2011,21(12):3003-3004.
[5] 洪雪花,欧利华,连云,等.影响水质高锰酸盐指数的测定因素分析[J].中国卫生检验杂志,2011,21(1):244,250.
[6] 李埮,仓书华,杨胜琴,等.关于生活饮用水中耗氧量测定影响因素的几点讨论[J].中国卫生检验杂志,2013,23(6):1609-1610.
[7] 祝正辉,唐永锋.酸性高锰酸盐指数的准确测定及影响因素分析[J].湘南城市学院学报:自然科学版,2014,23(4):58-60.
[8] 陈凡,王根礼,丁井井.提高酸性高锰酸盐指数测定准确性的几个因素[J].广东化工,2017,44(8):214-215.
[9] 顾建忠,周伟斌,高新芬.酸性高锰酸钾法测定水中耗氧量方法的改进[J].中国卫生检验杂志,2007,17(6):1132-1132.
[10] 刘桂英,张艳君.水质耗氧量的快速测定法与国家标准方法的比较[J].中国卫生检验杂志,2013,23(3):781-782.
[11] 张文改,黄丽,肖湖,等.连续流动分析测定水质中耗氧量的方法研究[J].中国卫生检验杂志,2013,23(18):3498-3500.
[12] 段星春,邓娜,陈少泓,等.水中高锰酸盐指数测定的连续流动分析法[J].安徽农业科学,2014,42(13):4021-4022.
[13] 唐慧颖,叶涣莹,陆秀兰,等.连续流动分析仪测定地表水中高锰酸盐指数的方法研究[J].环境科学与管理,2014,39(2):146-148.
[14] 罗霞,伍剑,陈杰,等.连续流动分析仪测定饮用水中高锰酸盐指数的方法研究[J].中国卫生检验杂志,2016,26(19):2754-2755.
[15] 张磊,杨光冠,王时雄.连续流动分析法和传统方法测定环境水样中化学需氧量的比较[J].苏州科技学院学报:工程技术版,2016,29(2):43-46.
[16] 朱建丰,陈军,封蓉芳.连续流动分析法测定包装饮用水中耗氧量[J].食品工业,2018,39(1):1-3.
[2] 姜建芳,闫芳,曲恒永.对水中耗氧量及包装材料中高锰酸钾消耗量实验的几点建议[J].中国卫生检验杂志,2008,18(3):569-569.
[3] 徐陆妹,楼冰冰,章春锋.生活饮用水中耗氧量检测不确定度的评定[J].中国卫生检验杂志,2008,18(1):161-163.
[4] 廖丽,汪洋,于露露,等.水质理化检验综合实验-地表水高锰酸盐指数的测定[J].中国卫生检验杂志,2011,21(12):3003-3004.
[5] 洪雪花,欧利华,连云,等.影响水质高锰酸盐指数的测定因素分析[J].中国卫生检验杂志,2011,21(1):244,250.
[6] 李埮,仓书华,杨胜琴,等.关于生活饮用水中耗氧量测定影响因素的几点讨论[J].中国卫生检验杂志,2013,23(6):1609-1610.
[7] 祝正辉,唐永锋.酸性高锰酸盐指数的准确测定及影响因素分析[J].湘南城市学院学报:自然科学版,2014,23(4):58-60.
[8] 陈凡,王根礼,丁井井.提高酸性高锰酸盐指数测定准确性的几个因素[J].广东化工,2017,44(8):214-215.
[9] 顾建忠,周伟斌,高新芬.酸性高锰酸钾法测定水中耗氧量方法的改进[J].中国卫生检验杂志,2007,17(6):1132-1132.
[10] 刘桂英,张艳君.水质耗氧量的快速测定法与国家标准方法的比较[J].中国卫生检验杂志,2013,23(3):781-782.
[11] 张文改,黄丽,肖湖,等.连续流动分析测定水质中耗氧量的方法研究[J].中国卫生检验杂志,2013,23(18):3498-3500.
[12] 段星春,邓娜,陈少泓,等.水中高锰酸盐指数测定的连续流动分析法[J].安徽农业科学,2014,42(13):4021-4022.
[13] 唐慧颖,叶涣莹,陆秀兰,等.连续流动分析仪测定地表水中高锰酸盐指数的方法研究[J].环境科学与管理,2014,39(2):146-148.
[14] 罗霞,伍剑,陈杰,等.连续流动分析仪测定饮用水中高锰酸盐指数的方法研究[J].中国卫生检验杂志,2016,26(19):2754-2755.
[15] 张磊,杨光冠,王时雄.连续流动分析法和传统方法测定环境水样中化学需氧量的比较[J].苏州科技学院学报:工程技术版,2016,29(2):43-46.
[16] 朱建丰,陈军,封蓉芳.连续流动分析法测定包装饮用水中耗氧量[J].食品工业,2018,39(1):1-3.