苯酚红比色法测定血清碳酸氢根

目的：建立一种简易准确的血清碳酸氢根比色测定方法。方法：过量标准盐酸与血清中的碳酸氢盐完全中和，剩余盐酸与标准碱溶液构成缓冲溶液，通过双波长比色测定缓冲溶液中苯酚红的显色强度定量碳酸氢根浓度。结果：血清碳酸氢根浓度在50．0mmol／L内与吸光率△A（A546nm--A623nm）线性良好（r=0．99997），精密度（CV）2．30％，平均回收率99．60％，与PEPC--MDH法对比相关性好（r=0．9603．n=46），健康成人静脉血碳酸氢根浓度（27．99±6．325）mmol／L。结论：操作简便易行，结果准确，重复性好，不需要特殊仪器和试剂。

Phenol Red Colorimetry for the Determination of Serum Bicarbonate Ion

Objective.. To establish an easy and accurate method for the determination of serum bicarbonate ion. Method： Com- pletely neutralized hydrochloride and serum bicarbonate ion. The residual hydrochloride and standard alkali were constituted for buffer solution. The color intensity of phenol red in buffer solution was determined by dual wavelengh colorimetry so as to quanti- ty the concentration of bicarbonate ion. Result： Serum bicarbonate ion concentration was in good linearity with absorbance△A （A546nm--A623nm） within 50.0mmol/L （r=0. 99997）, the accuracy was 2.30%, and average recovery rate was 99. 60%. Compared with PEPC--MDH method, it had good relativity （r=0. 9603, n=46）. Serum bicarbonate ion concentration was （27. 99±6. 325） for a healthy adult. Conclusion.. It is easy to operate and no need for special instrument and reagent with high accuracy and good repeatability