Quantitative analysis laws of molecular absorption

The UV/Vis domain has been widely exploited in quantitative analysis and the visible region for a particularly long time. The measurements are based upon the Lambert—Beer law which, under certain conditions, links the absorption of the light to the concentration of a compound in solution. 

The result was the Lambert—Beer law which is presented here in its current form  

In calling Iq the light intensity of the incident radiation before it passes through the medium of thickness /, that has an absorption coefficient k, expression 9.5 can be written in integrated form giving the transmitted intensity I (Equations 9.6 to 9.8)  

By replacing k with k C in expression 9.7 a new relation is obtained which is better known in the form of expression 9.4, in which the absorbance A is represented by one of the comparable expressions  

The Lambert-Beer law, considered in this approach as a postulate, has been the subject of different interpretations and demonstrations of statistical hypotheses. 

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