Lambert-Beers law Relationship between k and

The relationship between the absorption coefficient k and the molar absorptivity e is given by Lambert-Beer s law. The attenuation of the intensity over an infinitesimal optical path length dz is given by the derivative df(z)/dz in Eq. (53)  

After conversion to base-10 logarithms, one obtains the well-known Lambert-Beer s law  

the molar absorptivity s is related to the absorption coefficient k by 

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