阻抑反应动力学光度法测定微量钙

Kinetic Spectrophotometric Determination of Trace Calcium Ion Based on Its Inhibitory Effect

提出了测定微量钙的阻抑反应动力学光度法。在 0 .0 1 2mol L硫酸中 ,KBrO3氧化偶氮氯磷Ⅲ褪色 ,Ca2 + 可阻抑该褪色反应的速度。最大吸收波长为 5 5 0nm。Ca2 + 浓度在 0～ 1 .4mg L范围内与ΔA呈线性关系 ,检出限 0 .0 0 42mg L。方法准确、灵敏、简便。用于直接测定水样中的微量钙 ,获得满意的结果。

A kinetic spectrophotometric method for the determination of trace calcium was proposed. When chlorophosphonazo III was oxidized to decoloration by potassium bromate, calcium ion could decrease the reaction rate in diluted sulfuric acid medium. DeltaA was linear with the concentration of calcium in the range of 0.0 similar to1.4 mg/L at the maximum absorption wavelength of 550 nm, the detection limit for the detemination was 0.0042 mg/L. The method has been applied to the determination of calcium ion in natural water samples. The results were. in agreement with those using atomic absorption spectrophotometry.