高效毛细管电泳间接紫外检测血浆中钾、钙、镁

Indirect Determination of Potassium Calcium and Magnesium in Blood Plasma by High Performance Capillary Electrophoresis with UV-Detection

用高效毛细管电泳法,在pH 5.5的缓冲介质中用酒石酸作为络合剂,使血浆中钾、钠、钙、镁4种阳离子达到很好分离,用咪唑作为背景试剂进行了紫外检测。对电泳分离及紫外检测的各分析条件(包括背景缓冲溶液的pH值,咪唑溶液的浓度及酒石酸溶液的浓度等)作了试验并予以优化,上述4种离子的相互分离在4.5 min内顺利完成。文中给出了K+、Ca+、Mg2+的线性回归方程,其相关系数在0.998 4～0.999 4之间,证明了在各离子的峰面积与其浓度之间呈线性关系,3种离子的检出限(S/N=3)依次为0.20,0.12,0.06 mg.L-1。用迁移时间检测和用峰面积检测所得的RSD值(n=6)依次小于0.76%和2.83%。由于钠离子的吸收峰与系统峰重叠,钠的测定无法进行。回收率试验的结果在95.3%至104.2%。

Potassium sodium calcium and magnesium in blood plasma were separated by high performance capillary electrophoresis （HPCE） in a buffer medium of pH 5. 5, using tartaric acid as complexing agent. Irnidazole was used as background reagent in the UV-detectior, Various conditions for the CE separation and UV-detection （including pH value of background buffer solution, concentration of imidazole solution and concentration of tartaric acid solution） were studied and optimized. The above mentioned cations were separated from each other satisfactorily within 4. 5 min. Linear regression equations showing the relationships between the peak areas and concentrations of K^＋ , Ca^2＋ and Mg^2＋ were given with values of correlation coefficients in the range of 0. 998 4- 0. 999 4, and detection limits （S/N=3） of 0. 20, 0. 12 and 0.06 mg · L^-1 respectively. Values of RSD＇s （n=6） for measurments of migration time and peak area were found to be less than 0. 76% and 2. 83% respectively. Overlapping of the absorption peak with the system peak made the determination of sodium ion impossible. Test for recovery was performed and values of recovery were found in the range from 95. 34% to 104. 29%.