title: Spectrophotometric determination of Rare Earth Elements in aqueous nitric acid solutions for process control.
abstract: Noninvasive analytical control is of special interest for the complicated and hazardous production processes. On-line monitoring provides a unique opportunity to determine critical concentrations rapidly and without serious risks to operating personnel and the environment. Models for quantitative determination of concentrations of Rare Earth Elements in complex mixtures in nitric acid serve for these purposes. Here, the feasibility of simultaneous determination of cerium, praseodymium, and neodymium using the whole UV-vis spectroscopic range, together with chemometric data processing, is studied. The predictability of two chemometric techniques, partial least squares regression and correlation constrained multivariate curve resolution-alternating least squares are compared. Models' performances are analyzed in out-of-control cases.
authors.affiliation: Semenov Institute of Chemical Physics RAS, Kosygin Str. 4, 119991 Moscow, Russia.
authors.forename: Oxana Ye
authors.initials: OY
authors.lastname: Rodionova
authors.affiliation: Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
authors.forename: Tatyana I
authors.initials: TI
authors.lastname: Tikhomirova
authors.affiliation: Semenov Institute of Chemical Physics RAS, Kosygin Str. 4, 119991 Moscow, Russia; Institute of Natural and Technical Systems RAS, Kurortny pr. 99/18, 354024 Sochi, Russia. Electronic address: forecast@chph.ras.ru.
authors.forename: Alexey L
authors.initials: AL
authors.lastname: Pomerantsev
keywords: Multivariate curve resolution–alternating least squares (MCR–ALS); Out-of control behavior; Partial least squares (PLS); Rare Earth elements; Ultraviolet–visible (UV–vis) spectrophotometry