碱性桃红探针吸收光谱法测定吡哌酸

Determination of pipemidic acid by absorption spectrometry with alkaline peach pink as probe

建立了测定药物及生物样品中吡哌酸的单波长和双波长可见吸收光谱法。在可见光区和pH6.63Tris-HCl介质中,吡哌酸与碱性桃红反应生成红色二元离子缔合物,产生一个较强的正吸收峰和一个较强的负吸收峰,最大正吸收峰位于576nm,最大负吸收峰位于522nm,在此二波长处,两单波长法的线性范围均为0.02~3.7mg·L^-1,表观摩尔吸光系数(κ)分别为4.37×10^4L·mol^-1·cm^-1 和1.08×10^4L·mol^-1·cm^-1。当用双波长法测定时,线性范围为0.02~3.7mg·L^-1,表观摩尔吸光系数(κ)为5.45×10^4L·mol^-1·cm^-1。将576nm处的单波长法用于药物中吡哌酸含量的测定,回收率和相对标准偏差(n=5)分别为97.5%~102%和2.5%~2.8%。

A new single-wavelength and double-wavelength visible absorption spectrometry for the determination of pipemidic acid in drug and biological sample was established.In a Tris-HCl medium of pH 6.63 and in the visible region,pipemidic acid reacted with alkaline pink to form a red binary ion association complexes,as a result,a strong positive absorption peak and a strong negative absorption peak were produced.The largest positive absorption peak was located at 576 nm and the largest negative absorption peak was located at 522 nm.At the two wavelengths,Their linear range of two single wavelength method were 0.02~3.7 mg·L^-1.The apparent molar absorbance coefficient(κ)were 4.37×10^4 L·mol^-1·cm^-1 and 1.08×10^4 L·mol^-1·cm^-1,respectively.When the double-wavelength absorption spectrometry was used to determine the concentrations of pipemidic acid,its linear range was 0.02~3.7 mg·L^-1,the apparent molar absorbance coefficient(κ)was 5.45×10^4 L·mol^-1·cm^-1.The single-wavelength method at 576 nm was applied to the determination of pipemidic acid in drug with the recovery rate and the relative standard deviation(n=5)were 97.5%~102%and 2.5%~2.8%,respectively.