离子色谱分离-亚铁氰化钾-钙黄绿素偶合化学发光测定NO_2^-

Determination of nitrite by calcein-potassium ferrocyanide chemiluminescence after separation by ion chromatography

利用NO2-在酸性介质中氧化亚铁氰化钾为铁氰化钾,然后在碱性条件下和钙黄绿素化学发光反应相偶合,结合离子色谱分离和流动注射技术间接测定了NO2-。结果发现当钙黄绿素浓度为1.0×10-4mol/L,亚铁氰化钾浓度为2.0×10-4mol/L时,NO2-在1.0×10-5～1.0×10-7g/L范围内,化学发光强度与NO2-浓度成良好的线性关系(R=0.9958),检出限(3σ)为5.1×10-8g/L,对质量浓度为1.0×10-6g/LNO2-溶液进行11次平行测定,相对标准偏差为1.4%。将该方法用于蒸馏水和自来水中NO2-的测定,加标回收率分别为94.2%和107.1%。

NO2-was indirectly determined by means of calcein-K3[Fe(CN)6] chemiluminescence(CL) reaction,in which K4[Fe(CN)6] was oxidized to K3[Fe(CN)6] by NO2-in acidic medium.And the determination was performed after NO2-was separated by ion chromatography.The experimental conditions of the CL reactions were optimized.The results indicated that the best analytical conditions were 1×10-5 mol/L calcein and 2×10-5 mol/L K4[Fe(CN)6].The relationship between the CL intensity and the concentration of nitrite in the range ...