流动注射催化光度法测定NO_2^-的研究

Flow injection-catalytic spectrophotometry for determination of trace nitrite

以流动注射分光光度法,基于NO-2在酸性条件中对溴酸钾氧化胭脂红酸有催化作用这一原理测定NO-2。对实验条件进行了优化。实验结果表明,室温下,当cKBrO3=0.14mol L,c胭脂红酸=3.5×10-4mol L,cH2SO4=1.2mol L时,方法的线性范围为0.005～0.3μg mL,检出限为0.002μg mL。利用该方法对几种河水水样进行了测定。

Based on the color fading reaction of carminic acid with potassium bromate catalyzed by nitrite, a flow injection catalytic spectrophotometric method for the determination of nitrite was established. The experimental results showed that when the concentration of KBrO_3 was 0.14 mol/L, the concentration of carninic acid was 3.5×10^(-3) mol/L, the concentration of H_2SO_4 was 1.2 mol/L, and the experiment temperature was 25 ℃, the detection limit for NO^-_2 was 0.002 μg/mL, the linear range was 0.005～0.3 μg/mL. The method was applied to the determination of trace nitrite in river water with satisfactory results.