基于加压毛细管电色谱-激光诱导荧光联用技术研究离子强度对维生素B_2光解反应的影响

基于加压毛细管电色谱-激光诱导荧光检测法建立了分析维生素B2及其荧光性光解产物的方法,并用于研究维生素B2在水溶液和磷酸盐缓冲液中的光解反应速率与离子强度之间的关系。发现在C18毛细管色谱柱,流动相为含0.1%(v/v)三氟乙酸的乙腈水溶液,梯度洗脱,激发波长为488 nm,发射波长为520 nm的条件下,维生素B2及多种荧光性光解产物均得到很好的分离和检测,维生素B2的定量限为5×10-8mol/L。在此基础上研究了维生素B2的光降解反应受光照时间和离子强度等的影响。发现离子强度对维生素B2溶液的光解反应有显著影响,离子强度越大,光解速度越快。并进一步通过动力学计算得到维生素B2在水溶液和磷酸盐缓冲液中光解反应的表观速率常数。该研究为维生素B2的光稳定研究提供了一种高效分离和检测的方法,并为维生素B2的保存及临床使用提供了参考。

Study on effect of ionic strength on photolysis of vitamin B2 based on pressurized capillary electrochromatography coupled with laser induced fluorescence detection

A new method for the separation and analysis of vitamin B₂ and its fluorescent photolysis products was established based on pressurized capillary electrochromatography (pCEC) coupled with laser induced fluorescence (LIF) detection.The relationship between the photolysis reaction rate of vitamin B₂ and the ionic strength of aqueous solution or phosphate buffered solution was studied.The analysis was carried out by using a C18 capillary column.The mobile phase was acetonitrile-water with 0.1%(v/v) trifluoroacetic acid with gradient elution.The excitation wavelength was 488 nm and the emission wavelength was 520 nm.Vitamin B₂ and many fluorescent photolysis products were well separated.Based on the above, the influence of photo degradation rate of vitamin B₂ with ionic strength was studied.The apparent rate constant of photolysis was calculated by kinetic calculation.The results showed that the ionic strength had a significant effect on the photolysis of vitamin B₂ solution.The photolysis rate of vitamin B₂ was positively related to the ionic strength.This study provides a highly efficient method for the stability research of vitamin B₂, which may serve as a good reference for the preservation and clinical use of it.