【摘要】 基于在氨三乙酸(NTA)存在下,Mn(Ⅱ)对催化高碘酸钾(KIO4)氧化镁试剂Ⅰ(对硝基苯偶氮间苯二酚)的褪色反应有显著作用这一新体系,将催化光度法和流动注射技术联用,建立了一种可用于在线分析测定环境水样中痕量Mn(Ⅱ)的新方法。对体系和流动注射系统诸参数进行了优化,在优化条件下,在波长560nm处连续检测,Mn(Ⅱ)浓度在20~200μg.L-1范围内与峰高呈线性关系,线性方程为:H(mV)=0.1705c(μg.L-1)+0.1252,相关系数r=0.9993,采样频率为15样/h,最低检出限为1.3μg.L-1(3σ),相对标准偏差(RSD)=3.57%(n=8)。考察了多种共存离子的影响。该方法灵敏度高、选择性好、快速、简便,用于河水、工业废水和池塘水中Mn(Ⅱ)的检测,回收率为96%~102%。结果与原子吸收光谱法基本一致。更多还原

【Abstract】 An on-line supported flow-injection catalytic kinetic spectrophotometry new method for the determination of trace amounts of manganese(Ⅱ) in water was developed. The method is based on the significant catalytic action of trace manganese on the fading reaction of potassium periodate and magnesonⅠin the presence of nitrilotriacetic acid. The chemical and flow injection variables were optimized. The absorbance intensity was registered in this reaction solution at 560 nm. Under the optimum conditions, a standard curve with good linearity and broad linear range can be obtained in the range of 20-200 μg·L-1, the linear equation is H(mV)=0.170 5c(μg·L-1)+0.125 2(r =0.999 3), the detection limit is 1.3μg·L-1, the relative standard deviation is 3.57% (n=8), and the sampling frequency is 15 samples per hour. The interference of foreign iron was studied. Satisfied results were achieved with the proposed method to analyze the Mn(Ⅱ) in river water, waste water and pond water, and the range of recovery was 96%-102%. This method is simple, rapid, sensitive, accurate, highly selective and suitable for automatic and continuous analysis.更多还原