title: Investigating the discrimination potential of linear and nonlinear spectral multivariate calibrations for analysis of phenolic compounds in their binary and ternary mixtures and calculation pKa values.
abstract: Vanillin (VA), vanillic acid (VAI) and syringaldehyde (SIA) are important food additives as flavor enhancers. The current study for the first time is devote to the application of partial least square (PLS-1), partial robust M-regression (PRM) and feed forward neural networks (FFNNs) as linear and nonlinear chemometric methods for the simultaneous detection of binary and ternary mixtures of VA, VAI and SIA using data extracted directly from UV-spectra with overlapped peaks of individual analytes. Under the optimum experimental conditions, for each compound a linear calibration was obtained in the concentration range of 0.61-20.99 [LOD=0.12], 0.67-23.19 [LOD=0.13] and 0.73-25.12 [LOD=0.15] μgmL(-1) for VA, VAI and SIA, respectively. Four calibration sets of standard samples were designed by combination of a full and fractional factorial designs with the use of the seven and three levels for each factor for binary and ternary mixtures, respectively. The results of this study reveal that both the methods of PLS-1 and PRM are similar in terms of predict ability each binary mixtures. The resolution of ternary mixture has been accomplished by FFNNs. Multivariate curve resolution-alternating least squares (MCR-ALS) was applied for the description of spectra from the acid-base titration systems each individual compound, i.e. the resolution of the complex overlapping spectra as well as to interpret the extracted spectral and concentration profiles of any pure chemical species identified. Evolving factor analysis (EFA) and singular value decomposition (SVD) were used to distinguish the number of chemical species. Subsequently, their corresponding dissociation constants were derived. Finally, FFNNs has been used to detection active compounds in real and spiked water samples.
authors.affiliation: Department of Chemistry, Faculty of Science, Kurdistan University, P. O. Box 416, Sanandaj, Iran.
authors.forename: Zolaikha
authors.initials: Z
authors.lastname: Rasouli
authors.affiliation: Department of Chemistry, Faculty of Science, Kurdistan University, P. O. Box 416, Sanandaj, Iran. Electronic address: r.ghavami@uok.ac.ir.
authors.forename: Raouf
authors.initials: R
authors.lastname: Ghavami
mesh_terms: D001547:Benzaldehydes / Q000032:analysis*; D002138:Calibration; D000069956:Chocolate / Q000032:analysis; D005421:Flavoring Agents / Q000032:analysis*; D005504:Food Analysis / Q000379:methods; D016018:Least-Squares Analysis; D015999:Multivariate Analysis; D016571:Neural Networks, Computer; D010636:Phenols / Q000032:analysis; D013053:Spectrophotometry / Q000379:methods; D014641:Vanillic Acid / Q000032:analysis*; D014867:Water / Q000032:analysis
chemical_list: D001547:Benzaldehydes; D005421:Flavoring Agents; D010636:Phenols; D014867:Water; C069665:syringaldehyde; C100058:vanillin; D014641:Vanillic Acid
keywords: Artificial neural networks; Multivariate calibration methods; Multivariate curve resolution-alternating least squares (MCR-ALS); Partial least square; Partial robust M-regression; Phenolic compounds