微波流动注射催化分光光度法测定微量铱

Catalytic Spectrophotometric Determination of Ir(IV) by Microwave-oven induced Flow-injection Analysis

在酸性条件下 ,铱对高碘酸钾氧化 2 (2 胂酸基苯偶氮 ) 7 (2 ,6 二溴 4 甲基苯偶氮 ) 1,8 二羟基 3,6 萘二磺酸 (简称偶氮胂 DBM)褪色的反应具有催化作用 ,且微波场对该反应有强烈的加速作用。据此本文首次建立了测定微量铱的微波流动注射催化分光光度新方法。在 0 .0 2～ 0 .2 μg/mL范围内 ,铱的浓度CIr与log(A0 /A)具有良好的线性关系 ,回归方程为log(A0 /A) =4.5 0CIr(μg/L) - 0 .0 16 ,相关系数和检测限分别为r=0 .9979和 1.0× 10 -8g/mL .进样频率为每小时 5 0次 .该方法用于实际样品中铱的测定 ,结果令人满意 .

With the application of microwave flow injection analysis, a new catalytic spectrophotometric method has been established for the determination of micro mounts of Ir(IV), based on the catalytic action of Ir(IV) on the oxidation fading between 2 (2 Arsonophenylazo) 7 (2, 6 dibromo 4 methylphenyl azo) l,8 dihydroxy naphthalane 3, 6 disulphonic acid(Arsenazo DBM)and KIO 4 in the presence of H 2SO 4. Microwave radiation is found to accelerate the catalytic action greatly. In the range of Ir(IV) from 0.02 to 0.2 g/mL, the calibration curve of log( A 0/A ) versus the concentration of Ir(IV) was linear. The calibration equation was: log( A 0/A )=4.50 C Ir (μg/L)-0.016, with the correlation coefficient r =0.997 9 and the detection limit 1.0×l0 -8 g/mL. The system permitted 50 determinations per h. The method has been applied to the determination of Iridium in ore samples with satisfactory results.