title: Sensitive ergotamine determination in pharmaceuticals and biological samples using cloud point preconcentration and spectrofluorimetric detection.
abstract: A new cloud point extraction (CPE) method for ergotamine analysis using fluorimetric detection is described. Ergotamine from an aqueous solution was preconcentrated into a smaller surfactant-rich phase using nonionic surfactant polyoxyethylene(7.5)nonylphenylether (PONPE 7.5). Differently from the conventional CPE procedure in which the resulting surfactant-rich phase is diluted by a fluidificant before its analysis, in this method the fluorescence measurements were carried out directly onto the undiluted surfactant-rich phase. The high viscosity provided by the undiluted surfactant rich phase greatly improved the fluorescence emission of ergotamine, leading to a total enhancement factor of 1325. This spectral advantage plus the preconcentration factor achieved, contributed to the method sensitivity allowing the ergotamine determination at trace level concentration. Under optimal experimental conditions, a linear calibration curve was obtained from 3.81×10(-7) to 1.10μgmL(-1), with detection and quantification limits of 0.11 and 0.38pgmL(-1), respectively. The accuracy and versatility of the present methodology were proved by analyzing ergotamine in real samples of different natures such as pharmaceuticals, urine and saliva.
authors.affiliation: INQUISAL-CONICET, San Luis, Argentina.
authors.forename: Chien C
authors.initials: CC
authors.lastname: Wang
authors.forename: Liliana P
authors.initials: LP
authors.lastname: Fernández
authors.forename: María Roxana
authors.initials: MR
authors.lastname: Gómez
mesh_terms: D002138:Calibration; D019075:Electrophoresis, Capillary; D004878:Ergotamine / Q000032:analysis* / Q000592:standards / Q000652:urine; D006801:Humans; D006863:Hydrogen-Ion Concentration; D004364:Pharmaceutical Preparations / Q000032:analysis; D011092:Polyethylene Glycols / Q000737:chemistry; D012463:Saliva / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000592:standards; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D004364:Pharmaceutical Preparations; D013501:Surface-Active Agents; D011092:Polyethylene Glycols; D004878:Ergotamine