title: A novel sensor for monitoring of iron(III) ions based on porphyrins.
abstract: Three A(3)B porphyrins with mixed carboxy-, phenoxy-, pyridyl-, and dimethoxy-substituent functionalization on the meso-phenyl groups were obtained by multicomponent synthesis, fully characterized and used as ionophores for preparing PVC-based membrane sensors selective to iron(III). The membranes have an ionophore:PVC:plasticizer composition ratio of 1:33:66. Sodium tetraphenylborate was used as additive (20 mol% relative to ionophore). The performance characteristics (linear concentration range, slope and selectivity) of the sensors were investigated. The best results were obtained for the membrane based on 5-(4-carboxyphenyl)-10,15,20-tris(4-phenoxyphenyl)-porphyrin plasticized with bis(2-ethylhexyl)sebacate, in a linear range from 1 × 10(-7)-1 × 10(-1) M with a slope of 21.6 mV/decade. The electrode showed high selectivity with respect to alkaline and heavy metal ions and a response time of 20 s. The influence of pH on the sensor response was studied. The sensor was used for a period of six weeks and the utility has been tested for the quantitative determination of Fe(III) in recovered solutions from spent lithium ion batteries and for the quantitative determination of Fe(III) in tap water samples.
authors.affiliation: Faculty of Chemistry-Biology-Geography, West University of Timisoara, Timisoara, Romania. danavlascici@yahoo.com
authors.forename: Dana
authors.initials: D
authors.lastname: Vlascici
authors.forename: Eugenia
authors.initials: E
authors.lastname: Fagadar-Cosma
authors.forename: Iuliana
authors.initials: I
authors.lastname: Popa
authors.forename: Vlad
authors.initials: V
authors.lastname: Chiriac
authors.forename: Mayte
authors.initials: M
authors.lastname: Gil-Agusti
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000032:analysis; D007501:Iron / Q000032:analysis*; D057230:Limit of Detection; D008567:Membranes, Artificial; D011166:Porphyrins / Q000737:chemistry*; D011199:Potentiometry; D012996:Solutions; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D007477:Ions; D008567:Membranes, Artificial; D011166:Porphyrins; D012996:Solutions; D014867:Water; D007501:Iron