Citation: Wang Wei , Wang Tao , He Qushe , Feng Mingzhao , Riao Yuanmin , Wang Xiaojun , Ran Guoxia . Absorbance of Long-light-path in Spectrophotometry. Chinese Journal of Analytical Chemistry, 1991, 19(11): 1249-1252. [复制]
Absorbance of Long-light-path in Spectrophotometry
Employing waveguide theory and an approximation based on a modal conti-nuum,a relationship is developed theoretically among absorbance of an analyte and absorp-tion tube length(Z),analyte concentration(C),modal absorption coefficent(α1),scattering coefficient(β1)and coupling coefficient(D).The results show that absorbance is inversely proportional to the concentration of the analyte or absorption tube length,and is more than that expected from Lambert-Beer’s law.When Lambert Consine mission body is used as source at low concentration and when term 2Z(α1εCD)1/2(ε molar absorption coefficient)is below 1,the absorbance is directly proportional to the concentration and is a quadratio function of absorption tube length.As the absorption tuba length is increased the linear range of absorbance will move to lower concentration.So long-light-path system can be applied to the analysis of microamount of element.