Nouroozi Siavash, Mirshafian Razieh
Department of Chemistry, Faculty of Science, Zanjan University, Zanjan, 45195-313, Iran.
Talanta. 2009 Sep 15;79(4):1149-53. doi: 10.1016/j.talanta.2009.03.025. Epub 2009 Mar 24.
In this work, a new, simple and sensitive flow injection catalytic kinetic spectrophotometric determination of nitrite is reported based on catalytic effect of nitrite on the redox reaction between sulfonazo III and potassium bromate in acidic media. The reaction was monitored by measuring the decrease in the absorbance of sulfunazo III at 570 nm. Various chemical (such as the effect of acidity, reagents concentrations) and instrumental parameters (flow rate, reaction coil length, injection volume and temperature) were studied and were optimized. Under the optimum conditions calibration graph was linear in the nitrite concentration ranges of 8.00 x 10(-3)-3.00 x 10(-1) microg/ml (with slope of 2.40) and 3.50 x 10(-1)-1.80 microg/ml (with slope of 0.42). The detection limit was 6.00 x 10(-3) microg/ml of nitrite, the relative standard deviation (n=10) was 1.25% and 0.88% for 5.00 x 10(-2) and 2.00 x 10(-1)microg/ml of nitrite respectively. About 60 samples in 1h can be analyzed. The interfering effects of various chemical species were studied. The method was successfully applied in the determination of nitrite in food and environmental samples.
本文报道了一种基于酸性介质中亚硝酸盐对磺基偶氮Ⅲ与溴酸钾之间氧化还原反应的催化作用，测定亚硝酸盐的新型、简单且灵敏的流动注射催化动力学分光光度法。通过测量磺基偶氮Ⅲ在570nm处吸光度的降低来监测反应。研究并优化了各种化学参数（如酸度、试剂浓度的影响）和仪器参数（流速、反应盘管长度、进样体积和温度）。在最佳条件下，校准曲线在亚硝酸盐浓度范围8.00×10⁻³ - 3.00×10⁻¹μg/ml（斜率为2.40）和3.50×10⁻¹ - 1.80μg/ml（斜率为0.42）内呈线性。亚硝酸盐的检出限为6.00×10⁻³μg/ml，对于5.00×10⁻²和2.00×10⁻¹μg/ml的亚硝酸盐，相对标准偏差（n = 10）分别为1.25%和0.88%。每小时可分析约60个样品。研究了各种化学物质的干扰效应。该方法成功应用于食品和环境样品中亚硝酸盐的测定。
