长光路吸光度的研究  

Absorbance of Long-light-path in Spectrophotometry

作　　者：王卫[1] 王涛[1] 何去奢[1] 冯明昭[2] 廖远敏[2] 王晓军[2] 冉国霞[2] 

机构地区：[1]中国科学院新疆物理研究所,乌鲁木齐830011 [2]中国科学院新疆化学研究所

出　　处：《分析化学》1991年第11期1249-1252,共4页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金

摘　　要：本文根据光波导理论,用连续模的近似方法,导出了吸光度与吸收管长度(Z),离子浓度(C),模吸收系数(α_1),光散射系数(β_1)和耦合系数(D)的函数关系;结果表明吸光度不正比于浓度或吸收管长度,而且大于朗伯-比尔定律所预期值。以氙灯或钨灯做光源时,只有在低浓度区且2Z(α_1εCD)^(1/2)<1时,吸光度才正比于浓度,并与吸收管长度呈二次函数关系。随着吸收管长度的增加,线性区域将向低浓度方向移动。因此在光度分析中长光路系统最适合痕量元素的分析。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(α_1),scattering coefficient(β_1)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(α_1εCD)^(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.

关 键 词：吸光度 液芯光纤 长光路 光度分析 

分 类 号：O657.3[理学—分析化学]