title: Simple SPE-HPLC determination of some common drugs and herbicides of environmental concern by pulsed amperometry.
abstract: In this work the electrochemical behavior of substances of environmental concern [bentazone, atrazine, carbamazepine, phenytoin and its metabolite 5-(4-hydroxyphenyl)-5-phenylhydantoin, HPPH] on a glassy carbon working electrode (Ag/AgCl reference electrode) was studied with the aim to develop a HPLC method coupled with amperometric detection. Constant potential (DC), pulsed amperometric detection modes were studied. For the pulsed mode, several waveforms were set and investigated. Detection conditions were optimized as a function of eluent pH. In order to reduce the limits of detection and to analyze natural water samples, a SPE protocol was optimized to be coupled to the developed procedure. For this aim, five sorbents of different physico-chemical characteristics were tested optimizing a recovery procedure for each of the cartridge evaluated. At the optimized SPE conditions, recoveries were included in the range (R=90.2-100.5% for all the analytes, with excellent reproducibility (<%, n=3). The method detection limits obtained by pulsed amperometry after the SPE protocol (preconcentration factor 100) were 113 ng L(-1) (0.47 nmol L(-1)), 67 ng L(-1) (0.25 nmol L(-1)), 234 ng L(-1) (1.1 nmol L(-1)), for bentazone, HPPH and carbamazepine, respectively. Robustness of the method was assessed for each analyte at a concentration level corresponding to about three times the limit of detection, through the evaluation of intra-day (n=13) and inter-day tests (4 days, n=52). Finally the method was successfully applied for the analysis of a river sample (Po River, Turin, Italy).
authors.affiliation: Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Turin, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Rivoira
authors.affiliation: Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Turin, Italy.
authors.forename: R M
authors.initials: RM
authors.lastname: De Carlo
authors.affiliation: Istituto di Ricerca Sulle Acque, Consiglio Nazionale delle Ricerche (IRSA-CNR) Via del Mulino, 19, 20861 Brugherio, MB, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Cavalli
authors.affiliation: Department of Chemistry, University of Torino, via P. Giuria 5, 10125 Turin, Italy. Electronic address: mariaconcetta.bruzzoniti@unito.it.
authors.forename: M C
authors.initials: MC
authors.lastname: Bruzzoniti
mesh_terms: D001280:Atrazine / Q000032:analysis*; D001581:Benzothiadiazines / Q000032:analysis*; D002220:Carbamazepine / Q000032:analysis*; D002244:Carbon / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004563:Electrochemistry; D004566:Electrodes; D006540:Herbicides / Q000032:analysis*; D010672:Phenytoin / Q000032:analysis*; D045483:Rivers; D052616:Solid Phase Extraction / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D001581:Benzothiadiazines; D006540:Herbicides; D014874:Water Pollutants, Chemical; D002220:Carbamazepine; D010672:Phenytoin; D002244:Carbon; D001280:Atrazine; C002003:bentazone
keywords: Amperometric detection; Emerging contaminants; Glassy carbon electrode; RP-HPLC; Water