title: A new potentiometric electrode incorporating functionalized β-cyclodextrins for diclofenac determination.
abstract: This paper reports the preparation of diclofenac-selective membrane electrodes incorporating β-cyclodextrins: (2-hydroxypropyl)-β-cyclodextrin, heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin, and heptakis(2,3,6-tri-O-benzoyl)-β-cyclodextrin. Several plasticized poly(vinyl chloride) membranes of different compositions were tested with the best electrode being the one incorporating heptakis(2,3,6-tri-O-benzoyl)-β-cyclodextrin with the membrane plasticized with 2-nitrophenyloctyl ether. The electrode is characterized by a near-Nernstian response slope of -60.0 mV decade(-1) over the linear range of 5.0×10(-5)-1.0×10(-2) mol L(-1) and a limit of detection of 1.4×10(-5) mol L(-1). The proposed electrode can easily discriminate diclofenac ions from several inorganic and organic interferents and some common drug excipients. The electrode has a response time of 10s and can be used within a pH range of 6.2-8.5 over 10 months without any considerable deterioration. The electrical properties of the membrane electrode were studied by impedance spectroscopy. The notable advantages of the diclofenac-selective electrode include its high sensitivity, selectivity, cost-effectiveness, and comfortable application in drug and urine analysis.
authors.affiliation: Department of Analytical Chemistry and Instrumental Analysis, Chemical Faculty, Maria Curie-Skłodowska University, M. Curie-Skłodowska Sq. 3, 20-031 Lublin, Poland. Electronic address: j.lenik@poczta.umcs.lublin.pl.
authors.forename: Joanna
authors.initials: J
authors.lastname: Lenik
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D004008:Diclofenac / Q000032:analysis* / Q000652:urine; D058266:Dielectric Spectroscopy; D004566:Electrodes; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D011143:Polyvinyl Chloride / Q000737:chemistry; D011199:Potentiometry; D013607:Tablets / Q000737:chemistry; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D007477:Ions; D013607:Tablets; D047392:beta-Cyclodextrins; D004008:Diclofenac; D000073738:2-Hydroxypropyl-beta-cyclodextrin; C000609658:heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin; D011143:Polyvinyl Chloride
keywords: Diclofenac; Pharmaceutical analysis; Potentiometric electrode