title: Environmental Impact of Ionic Liquids: Automated Evaluation of the Chemical Oxygen Demand of Photochemically Degraded Compounds.
abstract: A novel automated fluorimetric technique was developed for the assessment of the chemical oxygen demand (COD) of ionic liquids (ILs) and combined with a photodegradation step to promote IL degradation. The method was implemented on a sequential injection analysis (SIA) system and is based on the reduction of cerium(IV) in the presence of irradiated ILs. Compounds incorporating the chloride anion were found to exhibit higher COD values and 1-butyl-3-methylimidazolium chloride ([bmim]+[Cl]-), 1-butyl-1-methylpyrrolidinium chloride ([bmpyr]+[Cl]-), and1-hexyl-3-methylimidazolium chloride ([hmim]+[Cl]-) also exhibited considerable photodegradability, whereas the cholinium cation and methanesulfonate and tetrafluoroborate anions showed resistance to photolysis. The developed methodology proved to be a simple, affordable, and robust method, showing good repeatability under the tested conditions (rsd <3.5 %, n=10). Therefore, it is expected that the developed approach can be used as a screening method for the preliminary evaluation of compounds' potential impact in the aquatic field. Additionally, the photolysis step presents an attractive option to promote degradation of ILs prior to their release into wastewater.
authors.affiliation: LAQV, Requimte, Departamento de Ciências Químicas, Laboratório de Química Aplicada, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
authors.forename: Susana P F
authors.identifier: http://orcid.org/0000-0003-2866-1591
authors.initials: SPF
authors.lastname: Costa
authors.affiliation: LAQV, Requimte, Departamento de Ciências Químicas, Laboratório de Química Aplicada, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.|Unidade de Investigação para o Desenvolvimento do Interior, Instituto Politécnico da Guarda, Av. Dr. Francisco de Sá Carneiro, n° 50, 6300-559, Guarda, Portugal.
authors.forename: Sarah A P
authors.identifier: http://orcid.org/0000-0003-1062-9868
authors.initials: SAP
authors.lastname: Pereira
authors.affiliation: LAQV, Requimte, Departamento de Ciências Químicas, Laboratório de Química Aplicada, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.|A3D-Association for Drug Discovery and Development, Rua do Baixeiro n° 38 Aveiro, Portugal.
authors.forename: Paula C A G
authors.identifier: http://orcid.org/0000-0002-1259-3873
authors.initials: PCAG
authors.lastname: Pinto
authors.affiliation: LAQV, Requimte, Departamento de Ciências Químicas, Laboratório de Química Aplicada, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.|Unidade de Investigação para o Desenvolvimento do Interior, Instituto Politécnico da Guarda, Av. Dr. Francisco de Sá Carneiro, n° 50, 6300-559, Guarda, Portugal.
authors.forename: André R T S
authors.identifier: http://orcid.org/0000-0003-3510-948X
authors.initials: ARTS
authors.lastname: Araujo
authors.affiliation: LAQV, Requimte, Departamento de Ciências Químicas, Laboratório de Química Aplicada, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
authors.forename: Marieta L C
authors.identifier: http://orcid.org/0000-0002-1383-4405
authors.initials: MLC
authors.lastname: Passos
authors.affiliation: LAQV, Requimte, Departamento de Ciências Químicas, Laboratório de Química Aplicada, Faculdade de Farmácia, Universidade do Porto, Rua Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
authors.forename: M Lúcia M F S
authors.identifier: http://orcid.org/0000-0001-6539-1741
authors.initials: MLMFS
authors.lastname: Saraiva
mesh_terms: D001331:Automation; D005470:Fluorometry; D052578:Ionic Liquids / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*; D055668:Photochemical Processes
chemical_list: D052578:Ionic Liquids; D010100:Oxygen
keywords: cerium(IV); chemical oxygen demand; fluorescence; ionic liquids; photolysis