title: Application of multivariate curve resolution alternating least squares method for determination of caffeic acid in the presence of catechin interference.
abstract: In the current article, preparation and application of a graphene oxide nanosheets-based sensor for electrochemical determination of caffeic acid (CA) in the presence of catechin is described. This measurement was performed using the differential pulse voltammetry (DPV) technique and chemometric methods such as multivariate curve resolution-alternating least squares (MCR-ALS). The modified sensor was characterized by various techniques such as Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, ultraviolet-visible, X-ray diffraction (XRD), and scanning electron microscopy (SEM). Operating conditions and influencing variables (involving several chemical and instrumental variables) were optimized with central composite rotatable design and response surface methodology. The second-order electrochemical data were generated by changing the pulse height in DPV, and after potential shift correction MCR-ALS was applied. Under the optimized conditions, the dynamic range for CA was from 0.5 to 100.0 μM and the detection limit was found to be 1.1×10(-9) M. The results revealed that the modified electrode shows an improvement in anodic oxidation activity of CA due to a marked enhancement in the current response compared with the bare carbon paste electrode. The modified electrode demonstrated good sensitivity, selectivity, and stability. The proposed method was successfully applied in determination of caffeic acid in the presence of unexpected electroactive interferences with a very high degree of overlapping such as catechin in real samples.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, Iran.
authors.forename: Marzieh
authors.initials: M
authors.lastname: Meshki
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, Iran. Electronic address: m.behpour@kashanu.ac.ir.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Behpour
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, Iran.
authors.forename: Saeed
authors.initials: S
authors.lastname: Masoum
mesh_terms: D001628:Beverages / Q000032:analysis; D002109:Caffeic Acids / Q000032:analysis* / Q000737:chemistry*; D002392:Catechin / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry; D016018:Least-Squares Analysis; D057230:Limit of Detection; D029561:Lythraceae / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D015999:Multivariate Analysis; D049329:Nanostructures / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry
chemical_list: D002109:Caffeic Acids; D010087:Oxides; D010936:Plant Extracts; D006108:Graphite; D002392:Catechin; C040048:caffeic acid
keywords: Caffeic acid; Carbon paste electrode; Differential pulse voltammetry; Graphene oxide; Multivariate curve resolution method; Second-order data