在线氧化还原流动注射分光光度法测定多贝斯

Determination of Doxium by Flow Injection Analysis with On-line Redox and Coloration Reactions

建立了在线氧化还原流动注射分光光度法测定多贝斯的新方法。研究了多贝斯与Fe3 + 的反应摩尔比和各种影响因素 ,发现Fe3 + 可以定量氧化多贝斯。产生的Fe2 + 与邻菲咯啉在弱酸性介质中生成稳定的红色络合物 ,该络合物在 5 12nm处的最大吸收与多贝斯浓度在 4 .2 4× 10 -6～ 4 .6 6× 10 -5mol/L范围内呈线性关系。回归系数为 0 .9987;方法的检出限为 5 .3× 10 -7mol/L ;相对标准偏差为 0 .5 % (n =8) ;采样率为 30次/h。

A novel on-line Redox flow injection analysis method for the determination of doxium has been established. The reaction between Fe3+ and doxium is studied firstly, including the reaction ratio and the influencing factors. It was found that Fe3+ can oxidize doxium quantitatively. The product, Fe2+, can form a red binary complex with 1,10-phenanthroline in week acidic solution. The absorbance of the color complex at 512 nm was linear to the concentration of doxium in the range of 4.24x10(-6) mol/L similar to4.66x10(-5) mol/L with correlation coefficient 0.9987, the detection limit was 5.3x10(-7) mol/L. The relative standard deviation was 0.5% (n=8) and sampling rate was 30 samples/h.