催化荧光法测定痕量草酸

Catalytic Fluorimetric Determination of Trace Oxalate

在硫酸介质中 ,草酸能催化重铬酸钾氧化罗丹明B褪色 ,使体系荧光猝灭 ,建立了催化荧光法测定草酸的新方法。催化反应在 50℃水浴中进行 1 0min ,为假零级反应。测定草酸的线性范围为 0 4～ 1 2 0mg·L- 1 ,其回归方程为ΔF =8 42c(mg·L- 1 ) +3 81 ,r=0 9983 ,检出限为 0 1 6mg·L- 1 。试验了 30种共存物质的干扰情况。此法用于生物样品中草酸含量的测定 ,结果满意。

A new catalytic fluorimetric method for the determination of trace oxalate has been developed. The method is based on the catalytic effect of oxalate on the oxidation of potassium dichromate with rhodamine B in sulfuric acid medium. The catalytic reaction takes place at 50degreesC for 10 min in a water bath and is a pseudo-zero-order reaction. The regression equation of calibration graph is DeltaF = 8.42c(mg(.)L(-1)) + 3.81(r = 0.998 3),and measuring range is 0.4-12.0 mg(.)L(-1), and the detection limit is 0.16 mg(.)L(-1). Interferences of 30 diverse materials were examined. The method has been applied to the determination of oxalate in biological samples with satisfactory results.