title: Use of the cross-section technique linked with multivariate calibration methods to resolve complex pesticide mixtures.
abstract: The potential of the cross-section (CS) approach in combination with the partial least squares (PLS) and principal component regression (PCR) was assessed in the resolution of a complex pesticide mixture showing twelve overlapped components in High Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD). Careful selection of the CS through the three-dimensional (3D) (A, lambda, t) data matrix gave two-dimensional (2D) signals with the best sensitivity for the determination of each pesticide. In all cases, the application of the PLS method demonstrated a better quantitative prediction ability than that of the PCR method. The CS-PLS approach is a powerful analytical tool. Ten pesticides were well-resolved, while for the other two pesticides of the mixture prediction ability was poor, and they could not be determined, probably due to their low net analytical signal. The CS-PLS model was evaluated by predicting the concentrations of independent test set samples. Finally, the proposed model was successfully applied for the determination of these pesticides in groundwater.
authors.affiliation: Department of Hydrogeology and Analytical Chemistry, University of Almeria, Spain.
authors.forename: A G
authors.initials: AG
authors.lastname: Frenich
authors.forename: J
authors.initials: J
authors.lastname: Martínez Vidal
authors.forename: M
authors.initials: M
authors.lastname: Martínez Galera
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D016018:Least-Squares Analysis; D008432:Mathematical Computing; D015999:Multivariate Analysis; D010575:Pesticides / Q000032:analysis*; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D012984:Software; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply / Q000032:analysis
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical