补锌、钙口服液中乳酸钙和葡萄糖酸锌含量的同时测定

 目的：研究补锌、钙口服液中葡萄糖酸锌和乳酸钙含量的测定。方法：以EDTA掩蔽Zn²⁺，间接高锰酸钾法测定钙的含量；在聚山梨酯-80存在下，以抗坏血酸为辅助配位体，于pH 4.4醋酸-醋酸钠缓冲溶液中，Zn²⁺与Meso-四-(4-甲基,3-磺基苯基)卟啉进行显色反应，应用分光光度法测定Zn²⁺。结果：高锰酸钾滴定法测定Ca²⁺得到精确结果，其S=0.03，RSD%=0.4；四元络合体系在pH4.2～5.5范围内对测锌具有较高灵敏度，最大吸收波长430 nm处的表观摩尔吸光系数为5.5×105 L·mol^-1·cm^-1。Zn(Ⅱ)浓度在0～0.18 μg·ml^-1范围内遵守比耳定律。结论：应用本法直接测定口服液中葡萄糖酸锌含量，不经分离，结果满意。

Study on the determination of calcium lactate and zinc gluconate in solution

OBJECTIVE To study the determination of calcium lactate and zinc gluconate. METHODS By masking zinc(Ⅱ) with EDTA, calcium ion was determinated with potassium permanganate method. Using vitamin C as complexing ligand, zinc(Ⅱ) reacted with meso-tatra-(4-methyl-3-sulfonate-phenyl) porphyrin (TTPS4) in the present of tween-80 and HAc-NaAc buffer(pH4.4).The resulting complex was determinated with spectrophotometry.RESULTS The determination of amounts of calcium in solution is 8.316 mg·ml^-1, S=0.03, RSD%=0.4. The complex of zinc with TTPS₄ has maxium absordtion at 430 nm, and its molar absorpitivity was 5.5×10-5 L·mol^-1·cm^-1, Beer'law was obeyed in the range of 0～0.18 μg·ml^-1.CONCLUSIONS The developed methods could be employed with high degree of precision and accuracy for the determination of calcium and zinc in peroral solution without prior separation.