连续流动注射-高锰酸钾法测定水中耗氧量  

Determination of oxygen consumption in water by continuous flow injection analysis using potassium permanganate

作　　者：郑倩清[1] 黄莹偲 朱晓晴 ZHENG Qianqing;HUANG Yingsi;ZHU Xiaoqing(Physical and Chemical Laboratory,Zhongshan Center for Disease Control and Prevention,Zhongshan,Guangdong 528400,China)

机构地区：[1]中山市疾病预防控制中心理化检验所,广东中山528400

出　　处：《预防医学》2023年第4期365-368,共4页CHINA PREVENTIVE MEDICINE JOURNAL

摘　　要：目的建立测定水中耗氧量的连续流动注射-高锰酸钾法。方法采用连续流动气泡间隔技术,混合水样和酸性高锰酸钾使用液,97℃在线加热反应,在最大吸收波长520 nm处检测高锰酸钾的电信号峰高。根据电信号峰高优化标准物质、硫酸浓度和高锰酸钾浓度。绘制标准曲线,测定方法的检出限、定量限和加标回收率。分别采用酸性高锰酸钾滴定法和连续流动注射-高锰酸钾法测定40份饮用水中COD_(Mn),并采用配对t检验比较。结果选择葡萄糖为标准物质,17.5%硫酸和3.2 mmol/L的高锰酸钾混合溶液为使用液。COD_(Mn)在0~6.00 mg/L范围内线性关系良好,相关系数≥0.999,方法检出限为0.013 mg/L,定量限为0.043 mg/L。40份饮用水的加标回收率为90.00%~105.00%,相对标准偏差为0.12%~1.36%。2种高锰酸盐指数标准物质的测定结果均在标准值范围内。连续流动注射-高锰酸钾法和酸性高锰酸钾滴定法测定COD_(Mn)的相对误差为1.55%~9.26%,差异无统计学意义(t=2.023,P=0.185)。结论本研究建立的连续流动注射-高锰酸钾法可用于水中耗氧量的批量检测。Objective To establish a continuous flow injection analysis with potassium permanganate for determination of oxygen consumption in water.Methods The water samples and acid potassium permanganate working solutions were mixed using the continuous flow bubble spacing,and subjected to online heating reaction at 97°C.The peak height of the electrical signal of potassium permanganate was measured at the maximum absorption wavelength of 520 nm,and the standard substance,sulfuric acid concentration and potassium permanganate concentration were optimized according to the peak height of the electrical signal.The standard curve was plotted to measure the limit of detection,the limit of quantification,and spiked recovery rate of the method.The CODMn concentration was determined in 40 drinking wa⁃ter samples using acid potassium permanganate titration and continuous flow injection analysis using potassium permanga⁃nate,and the determination results of the two methods were compared with paired t-test.Results Glucose was select⁃ed as the standard substance,and the mixture of 17.5%sulfuric acid and 3.2 mmol/L potassium permanganate was se⁃lected as the working solution.CODMn had a good linear relationship at concentrations of 0 to 6.00 mg/L,with a correla⁃tion coefficient of 0.999 and higher,a detection limit of 0.013 mg/L and a quantitation limit of 0.043 mg/L,respective⁃ly.The spiked recovery rates were 90.00%to 105.00%in 40 drinking water samples,with relative standard deviations of 0.12%to 1.36%.The determination results of two permanganate index standard substances were all within the range of standard values.The relative errors of CODMn concentration were 1.55%to 9.26%between the continuous flow injec⁃tion analysis using potassium permanganate and acid potassium permanganate titration,and there was no significant dif⁃ference(t=2.023,P=0.185).Conclusion The established continuous flow injection analysis with potassium permanganate is feasible for batch determination of oxygen consumption in water.

关 键 词：连续流动注射 高锰酸钾 水 耗氧量 

分 类 号：R123.1[医药卫生—环境卫生学]