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.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
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
关键词
吸光度
液芯光纤
长光路
光度分析
Absorbance
Long-light-path
Liquid-core-optical fiber
Capillary
Mode absorption coefficient
Mode seattering coefficient
Coulping coefficient
