Precision in Multi-Wavelength Spectroscopic Analysis with Classical-Least-Squares Regression

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 11 Issue 6 (2006) pp 394-401

Precision in Multi-Wavelength Spectroscopic Analysis with Classical-Least-Squares Regression

Miguel A. Cabezón and Alejandro C. Olivieri

Departamento de Química Analítica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario (S2002LRK), Argentina, aolivier@fbioyf.unr.edu.ar.
Received March 10, 2006. Accepted July 17, 2006.

Published online: 24 October 2006

Abstract. The determination of the concentrations of several analytes in a sample by measuring its absorbance at many different wavelengths is reviewed, with specific emphasis on prediction uncertainty. The standard concentration error can be estimated by an equation resembling the well-known expression for the univariate case. Spectra for aqueous mixtures of potassium permanganate and potassium dichromate at a suitable pH are studied, and the concentrations are calculated including the proper uncertainty estimates.

Key Words: Laboratories and Demonstrations; analytical chemistry; analytical spectroscopy; multi-wavelength regression; uncertainty estimation; error propagation

(*) Corresponding author. (E-mail: aolivier@fbioyf.unr.edu.ar)

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