title: Comparative study of the adsorption of acetaminophen on activated carbons in simulated gastric fluid.
abstract: Samples of commercial activated carbons (AC) obtained from different sources: Norit E Supra USP, Norit B Test EUR, and ML (Baracoa, Cuba) were investigated. The adsorption of acetaminophen, Co = 2500 mg/L, occured in simulated gastric fluid (SGF) at pH 1.2 in contact with activated carbon for 4 h at 310 K in water bath with stirring. Residual acetaminophen was monitored by UV visible. The results were converted to scale adsorption isotherms using alternative models: Langmuir TI and TII, Freundlich, Dubinin-Radushkevich (DR) and Temkin. Linearized forms of the characteristic parameters were obtained in each case. The models that best fit the experimental data were Langmuir TI and Temkin with R(2) ≥0.98. The regression best fits followed the sequence: Langmuir TI = Temkin > DR > LangmuirTII > Freundlich. The microporosity determined by adsorption of CO2 at 273 K with a single term DR regression presented R(2) > 0.98. The adsorption of acetaminophen may occur in specific sites and also in the basal region. It was determined that the adsorption process of acetaminophen on AC in SGF is spontaneous (ΔG <0) and exothermic (-ΔHads.). Moreover, the area occupied by the acetaminophen molecule was calculated with a relative error from 7.8 to 50%.
authors.affiliation: Instituto de Ciencia y Tecnología de Materiales, Facultad de Química, Universidad de la Habana, Havana, Cuba ; Programa de Pós-Graduação em Ciência e Engenharia de Materiais (PGMAT), Universidade Federal de Santa Catarina (UFSC), Florianópolis, Brazil.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Rey-Mafull
authors.affiliation: Centro de Ingeniería e Investigaciones Químicas, Havana, Cuba.
authors.forename: Juan E
authors.initials: JE
authors.lastname: Tacoronte
authors.affiliation: Laboratorio Reinaldo Gutiérrez, Havana, Cuba.
authors.forename: Raquel
authors.initials: R
authors.lastname: Garcia
authors.affiliation: Laboratorios MEDSOL, Havana, Cuba.
authors.forename: Jorge
authors.initials: J
authors.lastname: Tobella
authors.affiliation: Instituto de Ciencia y Tecnología de Materiales, Facultad de Química, Universidad de la Habana, Havana, Cuba.
authors.forename: Julio C
authors.initials: JC
authors.lastname: Llópiz
authors.affiliation: Facultad de Física, Universidad de la Habana, Havana, Cuba.
authors.forename: Alberto
authors.initials: A
authors.lastname: Iglesias
authors.affiliation: Programa de Pós-Graduação em Ciência e Engenharia de Materiais (PGMAT), Universidade Federal de Santa Catarina (UFSC), Florianópolis, Brazil.
authors.forename: Dachamir
authors.initials: D
authors.lastname: Hotza
keywords: Acetaminophen; Activated carbon; Adsorption; Isotherms; Simulated gastric fluid