毛细管电泳中移动反应界面法富集和检测尿样中的氧化苦参碱

Determination of Oxymatrine in Urine Samples by Capillary Electrophoresis with Stacking Induced by Moving Reaction Boundary

采用建立在移动反应界面理论上的体系进行尿样中氧化苦参碱的富集与定量检测。与传统的毛细管电泳相比,体系中引入了富集缓冲溶液(富集相)和分离缓冲溶液(分离相)。优化的条件如下:样品缓冲溶液为20mmol/L甲酸钠(用氨水调节pH至10.70),富集缓冲溶液为40mmol/L甲酸-甲酸钠(pH2.60),分离缓冲溶液为100mmol/L甲酸-甲酸钠(pH4.80);样品相压力进样1.4kPa×3min,富集相压力进样1.4kPa×7min,紫外检测波长210nm,电压21kV。氧化苦参碱在2.2～65mg/L的质量浓度范围内呈良好的线性关系(r=0.9991),检出限为0.74mg/L,灵敏度比常规毛细管电泳方法提高约70倍,重现性良好。该方法已经成功地应用于尿样中氧化苦参碱的检测。

A stacking system based on moving reaction boundary （MRB） for stacking and quantitative determination of oxymatrine （OMT） in urine samples was developed. The experimental conditions were optimized for the stacking of OMT as well as its separation. The optimized conditions were 20 mmol/L HCOONa （ pH 10. 70 adjusted by weak alkali of ammonia rather than strong alkali of sodium hydroxide） as sample buffer, 40 mmol/L HCOOH-HCOONa （pH 2.60） as stacking buffer, 100 mmol/L HCOOH-HCOONa （pH 4. 80） as separation buffer, 1. 4 kPa （3 min） sample phase injection and I. 4 kPa （7 min） stacking phase injection, 210 nm of detection wavelength, 21 kV of voltage. The linear response of OMT concentration ranged from 2.2 to 65 mg/L with high correlation coefficient （ r = 0. 999 l ）, the limit of detection （LOD） for OMT was 0. 74 mg/L, and sensitivity was enhanced by 70 times. This method can be well used for quantification of OMT in urine samples with high sensitivity and can be further applied in the investigation of pharmacokinetics.