title: Manganese(III) porphyrin-based potentiometric sensors for diclofenac assay in pharmaceutical preparations.
abstract: Two manganese(III) porphyrins: manganese(III) tetraphenylporphyrin chloride and manganese(III)-tetrakis(3-hydroxyphenyl)porphyrin chloride were tested as ionophores for the construction of new diclofenac-selective electrodes. The electroactive material was incorporated either in PVC or a sol-gel matrix. The effect of different plasticizers and additives (anionic and cationic) on the potentiometric response was studied. The best results were obtained for the PVC membrane plasticized with dioctylphtalate and having sodium tetraphenylborate as a lipophilic anionic additive incorporated. The sensor response was linear in the concentration range 3 × 10(-6) - 1 × 10(-2) M with a slope of -59.7 mV/dec diclofenac, a detection limit of 1.5 × 10(-6) M and very good selectivity coefficients. It was used for the determination of diclofenac in pharmaceutical preparations, by direct potentiometry. The results were compared with those obtained by the HPLC reference method and a good agreement was found between the two methods.
authors.affiliation: West University of Timisoara, 4 V. Parvan Ave, Timisoara 300223 Timis, Romania. danavlascici@yahoo.com
authors.forename: Dana
authors.initials: D
authors.lastname: Vlascici
authors.forename: Stela
authors.initials: S
authors.lastname: Pruneanu
authors.forename: Liliana
authors.initials: L
authors.lastname: Olenic
authors.forename: Florina
authors.initials: F
authors.lastname: Pogacean
authors.forename: Vasile
authors.initials: V
authors.lastname: Ostafe
authors.forename: Vlad
authors.initials: V
authors.lastname: Chiriac
authors.forename: Elena Maria
authors.initials: EM
authors.lastname: Pica
authors.forename: Liviu Calin
authors.initials: LC
authors.lastname: Bolundut
authors.forename: Luminita
authors.initials: L
authors.lastname: Nica
authors.forename: Eugenia
authors.initials: E
authors.lastname: Fagadar-Cosma
mesh_terms: D004008:Diclofenac / Q000032:analysis* / Q000737:chemistry; D004566:Electrodes; D008665:Metalloporphyrins / Q000737:chemistry*; D011199:Potentiometry / Q000295:instrumentation* / Q000379:methods*
chemical_list: D008665:Metalloporphyrins; D004008:Diclofenac; C027155:manganese(III) porphyrin