珍珠明目滴眼液中微量钙的共沉淀分离原子吸收光谱分析

Determination of Trace Calcium in Pearl Eye Drops By Coprecipitation Atomic Absorption Spectrophotometry

采用硝酸锶-碳酸钾共沉淀分离富集珍珠明目滴眼液中的微量钙，用原子吸收分光光度法测定其含量。进样溶液钙浓度在0.0～20．0μg·mL^-1范围内与其422．7nm处的吸光度成良好线性关系，检出限为0.06μg·mL^-1。该法用于珍珠明目滴眼液中钙的测定，具有灵敏、简便、快速、准确、重复性好，平均回收率为97．0％～98．3％，相对标准偏差RSD为0．4％。

The trace calcium in pearl eye drops was analyzed by atomic absorption spectrophotometry after the SrNO2-K2CO3 coprecipitation. The absorbance at 422. 7 nm is linear with the calcium concentration in the range of 0.0-20. 0 μg· mL^-1. The detection limit is 0. 06μg ·mL^-1 Ca. A new atomic absorption spectrophotometric method was proposed for the determination of calcium in pearl eye drops, with some advantages including high sensitivity, simplicity, rapidity and accuracy, The recovery is in the range of 97. 0%-98. 3%（n=5）. The RSD is 0. 4%. It proved a good method for the determination of calcium in pearl eye drops.