于浓度相同的结晶紫(CV)溶液中,加入不同浓度的十二烷基硫酸钠(SDS)组成一系列含有相同浓度CV和不同浓度SDS的混合溶液.在可见光区内对每一混合溶液测定其吸收值时,可见随SDS浓度的逐步递增,在CV-单聚体吸收峰的吸收值逐渐减少;而在CV-二聚体吸收峰的吸收值逐渐增加,且随CV-二聚体浓度增加而出现的CV-二聚体与CV-单聚体的吸收光谱线相互严重重叠,光谱形状也发生渐变.运用分光光度计所配备的Origin 7.5软件中储存的高斯多峰拟合法,可自动进行重叠光谱的解析和各光谱参数(包括y0,A1,A2,w1,w2,xc1及xc2)的拟合计算.文中还证示,每一参数与SDS浓度之间有明显的相关性,在两者之间所作的曲线上可找到明显的转折点,与转折点相对应的、在横坐标上的SDS浓度值即为SDS的临界胶束浓度(CMC)值.文中首次报道了用吸收光谱的半峰宽对SDS浓度作图所得曲线上的转折点求得SDS的CMC值.

It was shown that upon addition of sodium dodecyl sulfate (SDS) to solutions of crystal violet (CV) in the same concentration,making a series of solutions with graduation of concentration of SDS,a gradual decrease in absorbance at the abs.max.of CV-monomer and a gradual increase in absorbance at the abs.max.of CV-dimer were observed from the absorption spectra of each of the above mixed solutions measured in the visible spectral region,and serious over-lapping of absorption spectra of CV-monomer and CV-dimer,including changes in the spectral shape were also observed.Resolution of spectra-overlapping and the fitting calculation of various spectral-parameters were done automatically by using the Gaussian multi-peak fitting stored in the software Origin 7.5.It was shown that each of the parameters was related sensitively with the concentration of SDS,and a clear turning point was found from the plotting curve.The value of SDS concentration on the abcissa corresponding to the turning point of the curve was taken as the CMC value.The method of finding the CMC value by the turning point in the curve plotted was reported for the 1st time by the authors.