Question

Why is it important to measure the solutions from least concentrated to most concentrated in UV-Vis Spectroscopy?

Answer 1

In UV-Vis spectroscopy technique it is important to measure the solutions starting from least concentrated to most concentrated solutions. As we measure the lower concentration the absorbance is low for solution. Once we increase the concentration the transmittance that is the amount of light passing through the solution reduces and thereby the absorbance value goes up. The effect of any concentration error is minimal here. If otherwise the measurements are done starting from higher to lower concentration of solutions any remaining solue or solvent in the cuvette due to manual error will greatly change the resulting concentration of the solution to be measured for its absorbance. A large error in measurements can be observed in such cases and thus giving incorrect results. A higher value of absorbance would be oberved in place of correct lower value. thus it is adviced to start measuring solutions with lower to higher concentrations when using UV-Vis spectroscopy technique.