title: Assessment of the binding performance of histamine-imprinted microspheres by frontal analysis capillary electrophoresis.
abstract: Frontal analysis capillary electrophoresis was used to evaluate the binding performance of molecularly imprinted microspheres (MIM) toward its template histamine and analogs at pH 7, and compared to the high performance liquid chromatographic method. In both methods, batch binding was employed and the binding parameters were calculated from the measured concentration of unbound amine analytes and afforded comparable histamine equilibrium dissociation constants (Kd∼ 0.4 mM). FACE was easily carried out at shorter binding equilibration time (i.e. 30 min) and without the need to separate the microspheres, circumventing laborious and, in the case of the system under study, inefficient sample filtration. It also allowed for competitive binding studies by virtue of its ability to distinctly separate intact microspheres and all tested amines which could not be resolved in HPLC. Kd's for nonimprinted (control) microspheres (NIM) from FACE and HPLC were also comparable (∼ 0.6 mM) but at higher histamine concentrations, HPLC gave lower histamine binding. This discrepancy was attributed to inefficient filtration of the batch binding samples prior to HPLC analysis resulting in an over-estimation of the concentration of free histamine brought about by the presence of unfiltered histamine-bound microspheres.
authors.affiliation: Department of Chemistry, School of Science and Engineering, Ateneo de Manila University, Quezon City, Philippines.|Department of Chemistry, College of Arts and Sciences, Negros Oriental State University, Dumaguete City, Philippines.
authors.forename: Edwin F
authors.initials: EF
authors.lastname: Romano
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Chemistry, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Joselito P
authors.initials: JP
authors.lastname: Quirino
authors.affiliation: School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, NSW, Australia.
authors.forename: John L
authors.initials: JL
authors.lastname: Holdsworth
authors.affiliation: Department of Chemistry, School of Science and Engineering, Ateneo de Manila University, Quezon City, Philippines.
authors.forename: Regina C
authors.initials: RC
authors.lastname: So
authors.affiliation: Discipline of Chemistry, School of Environmental and Life Sciences, University of Newcastle, Newcastle, NSW, Australia.
authors.forename: Clovia I
authors.initials: CI
authors.lastname: Holdsworth
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D006632:Histamine / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D008863:Microspheres; D054802:Molecular Imprinting / Q000379:methods*
chemical_list: D006632:Histamine
keywords: Capillary electrophoresis; Frontal analysis capillary electrophoresis; Histamine; Histamine-imprinted microspheres; Molecularly imprinted polymers