Limitations by Lambert-Beers law

According to Bouguer-Lambert-Beer s law (see Section 3.3.2, eq. (3.57)) the absorbance in decadic units at any wavelength is measured as a sum of the partial absorbances of all the absorbing components  

In Chapter 3 Napierian units were used for absorption coefficients and absorbance. The reason was a simpler handling of the equations. Since instrumentation reads decadic units, they are used in most equations in this chapter. The decadic molar spectral absorption coefficient e of the compounds (i) varies with wavelength A. For this reason Bouguer-Lambert-Beer s law is restricted to monochromatic radiation. This restriction and the interactions between molecules in concentrated solutions cause two problems in applying the law to quantitative evaluation  

In Fig. 4.13b the opposite case is given. The bandwidth of the measurement light is smaller than the natural bandwidth. The smaller the bandwidth of the monochromator the better the absorbance value obtained will be, even at shoulders and at steep slopes of the band. The error by a too broad band measurement light is called a physical deviation of Lambert-Beer s law [41]. 

In addition to these deviations, which influence the linear relationship between concentration and the signal, any inadequate equipment can cause 

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