title: Simultaneous determination of three species with a single-injection step using batch injection analysis with multiple pulse amperometric detection.
abstract: In this work, the possibility of simultaneous determination of three compounds with a single-injection step using batch injection analysis with multiple pulse amperometric detection (BIA-MPA) is demonstrated for the first time. A sequence of three potential pulses (+1.25 V, +1.60 V, and +1.80 V) was applied with the acquisition of three separate amperograms. 8-Chlorotheophylline was detected selectively at +1.25 V, both 8-chlorotheophylline and pyridoxine at +1.60V and 8-chlorotheophylline, pyridoxine, and diphenhydramine at +1.80 V. Subtraction between the currents detected at the three amperograms (with the help of correction factors) was used for the selective determination of pyridoxine and diphenhydramine. The proposed method is simple, inexpensive, fast (60 injections h(-1)), and present selectivity for the determination of the three compounds in pharmaceutical samples, with results similar to those obtained by HPLC (95% confidence level).
authors.affiliation: Instituto de Química - Universidade Federal de Uberlândia, Av. João Naves de Ávila, 2121, Uberlândia, MG, Brazil.
authors.forename: Jhonys Machado
authors.initials: JM
authors.lastname: Freitas
authors.affiliation: Instituto de Química - Universidade Federal de Uberlândia, Av. João Naves de Ávila, 2121, Uberlândia, MG, Brazil.
authors.forename: Thiago da Costa
authors.initials: Tda C
authors.lastname: Oliveira
authors.affiliation: Instituto de Química - Universidade Federal de Uberlândia, Av. João Naves de Ávila, 2121, Uberlândia, MG, Brazil.
authors.forename: Denise Tofanello
authors.initials: DT
authors.lastname: Gimenes
authors.affiliation: Instituto de Química - Universidade Federal de Uberlândia, Av. João Naves de Ávila, 2121, Uberlândia, MG, Brazil.
authors.forename: Rodrigo Alejandro Abarza
authors.initials: RA
authors.lastname: Munoz
authors.affiliation: Instituto de Química - Universidade Federal de Uberlândia, Av. João Naves de Ávila, 2121, Uberlândia, MG, Brazil. Electronic address: emrichter@iqufu.ufu.br.
authors.forename: Eduardo Mathias
authors.initials: EM
authors.lastname: Richter
mesh_terms: D004155:Diphenhydramine / Q000032:analysis; D004563:Electrochemistry / Q000191:economics / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D007267:Injections / Q000379:methods*; D013806:Theophylline / Q000031:analogs & derivatives / Q000032:analysis; D013997:Time Factors
chemical_list: D004155:Diphenhydramine; D013806:Theophylline; C030093:8-chlorotheophylline
keywords: 8-Chlorotheophylline; Amperometric detection; Batch injection analysis; Diphenhydramine; Multielement analysis; Pyridoxine