碘-罗丹明B反荧光猝灭法测定药物中的乙酰半胱氨酸

目的采用碘-罗丹明B反荧光猝灭测定药物中乙酰半胱氨酸的含量。方法碘液(I^-_3)对罗丹明B(RB)具有荧光猝灭作用,使荧光信号强度减弱甚至消失,而乙酰半胱氨酸分子中的巯基可将I^-_3还原为I^-,使体系荧光信号再现。激发波长360 nm,发射波长580 nm,测量试液的荧光强度F,根据F值与溶液中的乙酰半胱氨酸浓度线性关系,完成乙酰半胱氨酸的反荧光测定。结果 0~10μmol·L^-1乙酰半胱氨酸与荧光强度有良好的线性关系(r=0.9970),检出限为4.8×10^-9 mol·L^-1。结论所用方法简便快速、准确可靠、灵敏度高,可用于药物中乙酰半胱氨酸的含量分析。

Determination of acetylcysteine in drugs by Anti-fluorescence quenching method on iodine-rhodamine B system

OBJECTIVE To determine the acetylcysteine in drugs based on counter-fluorescence quenching with iodine-rhodamine B.METHODS The iodine solution could make the fluorescence signal intensity of rhodamine B weak or even disappear,which is fluorescence quenching effect.I-3 can be reduced to I-by hydrosulfuryl group in acetylcysteine,and then the fluorescence reappears.In this paper,360 nm and 580 nm were chosen as the excitation and emission wavelength respectively for measurement of the fluorescence intensity of sample solution,and acetylcysteine concentration of sample solution was determined according to linear relationship between the value of F and concentration of sample solution.RESULTS Good linearity was observed for the analyte in the range of 0-10μmol·L-1 with the correlation coefficient of r=0.9970.The limits of detection based on the signal to noise ratio of 3 was 4.8×10-9 mol·L-1.CONCLUSION The method is simple,rapid,accurate and reliable,which can be used for the analysis of N-acetylcysteine in drugs.