title: Vitamins B1 and B6 tubular electrodes as FIA detectors; their use in the analysis of pharmaceutical products.
abstract: Ion-selective electrodes without an inner reference solution and tubular potentiometric detectors for the determination of vitamins B1 and B6 in pharmaceutical preparations by flow injection analysis (FIA) are reported. The membranes were prepared with the vitamin tetra(2-chlorophenyl)borate (TCPB) dissolved in o-nitrophenyloctyl ether (o-NPOE) and immobilized on PVC. Intrinsic behaviour of the tubular detectors was assessed using a low-dispersion single-channel FIA manifold and was compared with conventionally-shaped electrodes using the same membrane. Data obtained in the determination of vitamins B1 and B6 in pharmaceutical preparations with a double channel flow injection manifold incorporating the tubular detectors are presented and compared with those obtained by the U.S. Pharmacopeia method and by direct potentiometry with conventionally-shaped electrodes.
authors.affiliation: Physical Chemistry Department, Faculty of Pharmacy, University of Porto, Portugal.
authors.forename: J L
authors.initials: JL
authors.lastname: Lima
authors.forename: M
authors.initials: M
authors.lastname: Conceição
authors.forename: B S
authors.initials: BS
authors.lastname: Montenegro
authors.forename: A M
authors.initials: AM
authors.lastname: Silva
mesh_terms: D004566:Electrodes; D017022:Flow Injection Analysis; D011199:Potentiometry; D011736:Pyridoxine / Q000032:analysis*; D013831:Thiamine / Q000032:analysis*
chemical_list: D011736:Pyridoxine; D013831:Thiamine