偶合反应流动注射化学发光分析法测定有机还原性物质的研究

Determination of trace-micro organic reductants by flow injection coupling chemiluminescence analysis

基于重铬酸钾在酸性介质下氧化有机还原性物质生成Cr3+的反应与Luminol H2O2 Cr3+化学发光反应相偶合,建立了一种广普、快速测定痕量至微量有机还原性物质的新方法.研究并优化了化学发光检测的条件,测定了11种常见有机还原性物质.方法的检出限(mol/L)分别为:抗坏血酸,1.2×10-9;尿酸,1.5×10-7;肌酸酐,3.0×10-7;谷胱甘肽,5.4×10-6;盐酸羟胺,6.0×10-8;硫酸肼,4.8×10-7;水合肼,5.2×10-7;甲醛,6.1×10-7;乙醛,5.3×10-7;葡萄糖,7.0×10-6;果糖,8.3×10-6.测定的相对标准偏差(RSD%,n=6)在1.2%～2.3%范围内.

The chemiluminescent (CL) reaction of LuminolH2O2Cr(Ⅵ) with reducing agents has been investigated for determination of certain organic reductants. Based on the fast reduction reaction between chromium(Ⅵ) and organic reductants in acid medium, chromium(Ⅲ) is generated to couple with LuminolH2O2 CL reaction in alkaline aqueous solution. Parameters affecting CL detection, such as CL reaction reagents concentration, pH value, reaction temperature, sodium hydroxide concentration and flow rate are optimized. Detection limits (in mol/L) are found to be: ascorbic acid, 1.2×10-9; uric acid, 1.5×10-7; creatinine, 3.0×10-7; glutathione, 5.4×10-6; hydroxylamine, 6.0×10-8; hydrazine sulfate, 4.8×10-7; hydrazine hydrate, 5.2×10-7; formaldehyde; 6.1×10-7; acetaldehyde, 5.3×10-7; glucose, 7.0×10-6; fructose, 8.3×10-6. The relative standard deviation of the CL intensity is in the range of 1.2%～2.3%(n=6).