Standard addition calibration: Is it enough for an analytical result estimation?. Spectrophotometric experiments for analyte quantitation in real samples

Abstract

Analytical method validation is the first step for quantitative analysis, and both validation and quantitation are usual and fundamental tasks in analytical work; hence it is extremely important to perform them in the most rigorous way to obtain quality results. Then, in this sense, are we able to answer the question: is standard addition calibration enough for reliable result estimations? Systematic errors due to matrix effects must be identified and corrected for an accurate analyte quantitative determination; this is possible when external calibration, standard addition calibration and Youden calibration are performed together. The multiplicity of combinations of analytes, sample matrix and analytical techniques for method validation and subsequent analyte quantitation are very attractive and stimulating for students of advanced Analytical Chemistry courses because they can work with “real samples” through the integration of knowledge and skills previously acquired in order to obtain reliable results. In fact, the basis of this work can be extended to research, industrial, and/or any application area where the validation of a method is required for further accurate quantitative determination. In the present work spectrophotometric experiments for the validation of three UV-Visible methodologies were adopted and carried out with real samples.