等吸收点分光光度法直接测定二组份浓度比

Direct Determination of ConcentrationRation by Spectrophotometry at IsoabsorptivePoint

根据等吸收点原理，在普通光度计上建立了直接测定同一显色体系中吸收光谱有较大重叠的Ｍ、Ｎ两组份之浓度比的方法。导出的计算公式为，式中ａ为Ｍ组份在Ｍ组份的最大吸收波长λ＿１和等吸收点波长λ＿２处的吸光系数之比值；ｂ为Ｎ组份在λ＿１、λ＿２两波长处吸光系数之比值；Ａ＿ｘ为样品在λ＿１、λ＿２处吸光度之比值。应用该方法测定了血清中Ｃｕ／Ｚｎ比值。结果较为满意。

Based on the principle of isoabsorption,a method is described to determine the con-centration ratio of two components M and Nwhose absorption spectra overlap signifi-cantly,The formula is c_M/c_N=(a-A_x)/A_x-b),where a stands for the ratio of ab-sorbance of component M atλ_1(maximumabsorption wavelength for M component)tothat of M at λ_1(isoabsorptive wavelength),brepresents the ratio of absorbances of com-ponent N at λ_1 andλ_2, and A_x is the ratio ofabsorbances of the sample at λ_1 and λ_2,Satis-factory result was obtained when the methodwas used to determine the ratio of Cu(Ⅱ)/Zn(Ⅱ)in serum.