Jump to main content
Jump to site search

Issue 2, 2016
Previous Article Next Article

Non-linear multivariate curve resolution applied to the spectrophotometric determination of cerium(III) in aqueous nitric acid solutions for process control

Author affiliations

Abstract

It is shown that the recently proposed Non-Linear Multivariate Curve Resolution (NL-MCR) method can be effectively employed to develop an accurate calibration of cerium(III) using spectrophotometry measurements of mixtures of rare earth elements in nitric acid. Spectroscopic techniques provide a unique opportunity for the in-line determination of critical concentrations rapidly and without serious risks to operating personnel and the environment. Cerium has no absorbance bands in the visual and near-infrared range. In the ultraviolet range cerium(III) has a unique large peak which overlaps with even larger peaks of nitric acid. In the case of in-line control, where conventional analytical means are limited, we encounter a peak flattening and, consequently, a Lambert–Beer law violation. Therefore, the conventional calibration methods, such as Partial Least Squares (PLS) and Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS), yield useless results. Our previous attempt to overcome Beer's law violation by introducing a non-linear constraint in the MCR-ALS procedure failed. Application of the NL-MCR method with specially selected transition function not only yields accurate cerium determination but also provides an opportunity to assess the unknown nitric acid concentration in new samples. It is shown that the established calibration models are stable to some extent for out-of-control cases.

Graphical abstract: Non-linear multivariate curve resolution applied to the spectrophotometric determination of cerium(iii) in aqueous nitric acid solutions for process control

Back to tab navigation

Publication details

The article was received on 08 Sep 2015, accepted on 30 Nov 2015 and first published on 02 Dec 2015


Article type: Paper
DOI: 10.1039/C5AY02393A
Author version available: Download Author version (PDF)
Citation: Anal. Methods, 2016,8, 435-444
  •   Request permissions

    Non-linear multivariate curve resolution applied to the spectrophotometric determination of cerium(III) in aqueous nitric acid solutions for process control

    O. Ye. Rodionova and A. L. Pomerantsev, Anal. Methods, 2016, 8, 435
    DOI: 10.1039/C5AY02393A

Search articles by author

Spotlight

Advertisements