title: Potentiometric perchlorate determination at nanomolar concentrations in vegetables.
abstract: In this work, an expeditious method based on the multi-commutated flow-analysis concept with potentiometric detection is proposed to perform determinations of the emergent contaminant perchlorate in vegetable matrices down to nanomolar concentration. To accomplish the task, a tubular shaped potentiometric sensor selective to perchlorate ion was constructed with a PVC membrane containing 12mmol/kg of the polyamine bisnaphthalimidopropyl-4,4'-diaminodiphenylmethane and 2-nitrophenyl phenyl ether 68% (w/w) as plasticizer casted on a conductive epoxy resin. Under optimal flow conditions, the sensor responded linearly in the concentration range of 6.3×10-7-1.0×10-3mol/L perchlorate. In order to extend the determinations to lower concentrations (4.6(±1.3)×10-10mol/L perchlorate), a column packed with 70mg of sodium 2,5,8,11,14-pentaoxa-1-silacyclotetradecane-polymer was coupled to the flow-system thus enabling prior pre-concentration of the perchlorate. The proposed procedure provides a simpler alternative for the determination of perchlorate in foods, nowadays only allowed by sophisticated and expensive equipment and laborious methods.
authors.affiliation: Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901 Recife, Pernambuco, Brazil; Departamento de Química, Universidade Federal Rural de Pernambuco, 52171-900 Recife, PE, Brazil.
authors.forename: Dilmo M S
authors.initials: DM
authors.lastname: Leoterio
authors.affiliation: Departamento de Química Fundamental, Universidade Federal de Pernambuco, 50670-901 Recife, Pernambuco, Brazil.
authors.forename: Ana Paula S
authors.initials: AP
authors.lastname: Paim
authors.affiliation: Departamento de Química, Universidade Federal Rural de Pernambuco, 52171-900 Recife, PE, Brazil.
authors.forename: Mônica F
authors.initials: MF
authors.lastname: Belian
authors.affiliation: Centro de Tecnologias Estratégicas do Nordeste, 50670-901 Recife, Pernambuco, Brazil.
authors.forename: André
authors.initials: A
authors.lastname: Galembeck
authors.affiliation: Departamento de Química, Universidade Federal Rural de Pernambuco, 52171-900 Recife, PE, Brazil.
authors.forename: André F
authors.initials: AF
authors.lastname: Lavorante
authors.affiliation: LAQV, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
authors.forename: Edgar
authors.initials: E
authors.lastname: Pinto
authors.affiliation: LAQV, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
authors.forename: Célia G
authors.initials: CG
authors.lastname: Amorim
authors.affiliation: LAQV, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
authors.forename: Alberto N
authors.initials: AN
authors.lastname: Araújo
authors.affiliation: LAQV, REQUIMTE, Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal. Electronic address: mcbranco@ff.up.pt.
authors.forename: Maria C B S M
authors.initials: MC
authors.lastname: Montenegro
mesh_terms: D000814:Aniline Compounds; D009281:Naphthalenes / Q000032:analysis* / Q000737:chemistry; D009574:Nitro Compounds / Q000032:analysis* / Q000737:chemistry; D010472:Perchlorates / Q000032:analysis*; D010647:Phenyl Ethers / Q000032:analysis* / Q000737:chemistry; D010968:Plasticizers; D011073:Polyamines / Q000032:analysis* / Q000737:chemistry; D011143:Polyvinyl Chloride; D011199:Potentiometry / Q000379:methods*; D016482:Urinalysis; D014675:Vegetables / Q000737:chemistry*; D001559:Benzhydryl Compounds
chemical_list: D000814:Aniline Compounds; D009281:Naphthalenes; D009574:Nitro Compounds; D010472:Perchlorates; D010647:Phenyl Ethers; D010968:Plasticizers; D011073:Polyamines; D011143:Polyvinyl Chloride; C000618992:2-nitrophenyl phenyl ether; C000618991:bisnaphthalimidopropyl-4,4'-diaminodiphenylmethane; C009505:4,4'-diaminodiphenylmethane; D001559:Benzhydryl Compounds; C494474:perchlorate
keywords: Continuous flow-system; Perchlorate; Potentiometric sensor; Pre-concentration; Vegetable samples