title: Determination of imidacloprid in water samples via photochemically induced fluorescence and second-order multivariate calibration.
abstract: This paper presents a new method for the determination of imidacloprid in water samples; one of the most widely used neonicotinoid pesticides in the farming industry. The method is based on the measurement of excitation-emission spectra of photo-induced fluorescence (PIF-EEMs) associated with second-order multivariate calibration with a parallel factor analysis (PARAFAC) and unfolded partial least squares coupled to residual bilinearization (U-PLS/RBL). The second order advantage permitted the determination of imidacloprid in the presence of potential interferences, which also shows photo-induced fluorescence (other pesticides and/or unexpected compounds of the real samples). The photoreaction was performed in 100-μl disposable micropipettes. As a preliminary step, solid phase extraction on C18 (SPE-C18) was applied to concentrate the analyte and diminish the limit of detection. The LOD was approximately 1 ng mL(-1), which is suitable for detecting imidacloprid in water according to the guidelines established in North America and Europe. The PIF-EEMs coupled to PARAFAC or U-PLS/RBL was successfully applied for the determination of imidacloprid in different real water samples, with an average recovery of 101±10%.
authors.affiliation: Departamento de Química Inorgánica y Analítica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Casilla 233, Chile. Electronic address: edfuentes@ciq.uchile.cl.
authors.forename: Edwar
authors.initials: E
authors.lastname: Fuentes
authors.affiliation: Departamento de Química Inorgánica y Analítica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Casilla 233, Chile.
authors.forename: Camila
authors.initials: C
authors.lastname: Cid
authors.affiliation: Departamento de Química Inorgánica y Analítica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Casilla 233, Chile.
authors.forename: María E
authors.initials: ME
authors.lastname: Báez
mesh_terms: D002851:Chromatography, High Pressure Liquid; D060766:Drinking Water / Q000032:analysis; D005163:Factor Analysis, Statistical; D005453:Fluorescence; D060587:Groundwater / Q000032:analysis; D007093:Imidazoles / Q000032:analysis* / Q000528:radiation effects; D008900:Mineral Waters / Q000032:analysis; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000032:analysis* / Q000528:radiation effects; D010575:Pesticides / Q000032:analysis* / Q000528:radiation effects; D015203:Reproducibility of Results; D052616:Solid Phase Extraction; D013050:Spectrometry, Fluorescence; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000528:radiation effects
chemical_list: D060766:Drinking Water; D007093:Imidazoles; D008900:Mineral Waters; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010575:Pesticides; D014874:Water Pollutants, Chemical; C082359:imidacloprid
keywords: Imidacloprid; Multivariate calibration; Photo-induced fluorescence; Water