title: Evaluation of multiwavelength chromatograms for the quantification of mixtures of pesticides by high-performance liquid chromatography-diode array detection with multivariate calibration.
abstract: Three multivariate calibration methods, partial least squares (PLS-1 and PLS-2) and principal component regression, were applied to the simultaneous determination of the five pesticides iprodione, procymidone, chlorothalonil, folpet and triazophos by high-performance liquid chromatography with diode array detection. Such detection gives multiwavelength chromatograms from a single analysis of one sample. In this paper, calibration models at two different wavelengths were developed to resolve mixtures of five pesticides with overlapping chromatographic peaks. The first model, carried out at 220 nm as detector compromise wavelength, yielded satisfactory sensitivity for accurate estimation of the concentration of iprodione, procymidone, chlorothalonil and folpet and the second model, at 200 nm, was used for accurate estimation of triazophos. Both calibration models were evaluated using the chromatograms and first-derivative (1D) chromatograms by predicting the concentrations of independent test set samples. Finally, the proposed 1D calibration models were successfully applied to the determination of these pesticides in groundwater and soil samples. In all cases, the PLS-1 calibration method showed superior quantitative prediction ability than the PLS-2 or principal component regression methods.
authors.affiliation: Department of Analytical Chemistry, University of Almería, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Martínez Galera
authors.forename: J L
authors.initials: JL
authors.lastname: Martínez Vidal
authors.forename: A
authors.initials: A
authors.lastname: Garrido Frenich
authors.forename: M D
authors.initials: MD
authors.lastname: Gil García
mesh_terms: D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives / Q000032:analysis; D001643:Bridged Bicyclo Compounds / Q000032:analysis; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005618:Fresh Water / Q000032:analysis / Q000737:chemistry; D005659:Fungicides, Industrial / Q000032:analysis*; D006827:Hydantoins; D007306:Insecticides / Q000032:analysis; D008956:Models, Chemical; D009570:Nitriles / Q000032:analysis; D063086:Organothiophosphates / Q000032:analysis; D010573:Pesticide Residues / Q000032:analysis*; D010797:Phthalimides / Q000032:analysis; D015203:Reproducibility of Results; D012987:Soil / Q000032:analysis; D013056:Spectrophotometry, Ultraviolet; D014230:Triazoles / Q000032:analysis
chemical_list: D001643:Bridged Bicyclo Compounds; D005659:Fungicides, Industrial; D006827:Hydantoins; D007306:Insecticides; D009570:Nitriles; D063086:Organothiophosphates; D010573:Pesticide Residues; D010797:Phthalimides; D012987:Soil; D014230:Triazoles; D000620:Aminoimidazole Carboxamide; C012584:triazophos; C035988:procymidone; C005806:tetrachloroisophthalonitrile; C033148:iprodione; C005020:folpet