2-(8'-羟基喹啉-5'-磺酸-7'-偶氮)-变色酸络合解离法测定血清钙

UVspectrophotometric determination of calcium in serum by complexing with 2(8′quinolinol5′sulfo7′azo)chromotropic acid and dissociated by EGTA

目的建立灵敏度高、选择性好的２（８′羟基喹啉５′磺酸７′偶氮）变色酸（简称８Ｑ５ＳＡＣ）血清钙络合解离测定法。方法在甘氨酸ＮａＯＨ缓冲介质中，８Ｑ５ＳＡＣ与钙、镁等金属离子络合显色，加入ＥＧＴＡ使８Ｑ５ＳＡＣ与钙解离，以测定吸光度的下降值分析血清钙。对反应条件、方法性能进行系统研究。结果该法线性０～５ｍｍｏｌ／Ｌ，平均回收率９９３％，变异系数０５６％～１８１％。与邻甲酚酞络合酮法对照，ｒ＝０９９８，Ｐ＞０５；与甲基百里酚蓝法对照，ｒ＝０９９３，Ｐ＞００５。结论该法试剂稳定，灵敏度、选择性及测试线性均优于或相当于邻甲酚酞络合酮法和ＭＴＢ法，可用于血清钙的常规分析。

Objective To create a highsensitivity and goodselectivity method for the determination of calcium in serum by UVspectrophotometry with 2(8′Quinolinol5′sulfo7′azo)chromotropic acid (8Q5SAC).Methods 8Q5SAC was used as a coloring reagent to react on such metalions as calcium and magnesium and to develop color in the glycineNaOH buffer system. EGTA was added for dissociating calcium from 8Q5SAC. Calcium was analyzed by the determination of the absorbent declining volume. The systematic studies of reaction conditions and properties of the method were made.Results The linearity was 0～5(mmol/L), the average rate of recovery was 99.3%, and CV 0.56%～1.81%. Comparison with OCPC, showed that r=0.998, P>0.5 and with MTB, r=0.993, P>0.05.Conclusions The reagent is stable. Its sensitivity, selectivity and linearity are better than or the same as those of OCPC′s and MTB′s. The method is suitable for the routine analysis of calcium in serum, especially for automatic analysis.