title: Uncertainty in the determination of glucose in aqueous solutions by high-performance liquid chromatography with evaporative light scattering detection.
abstract: The determination of glucose and other carbohydrates is the most widespread chemical analysis that is performed within the industries of food, beverage, forage, biomass, pulp and paper, pharmaceuticals among others. Besides that, sugar refineries need to control their products, by-products and effluents, and furthermore, glucose in the sucrose refining process, is considered an impurity, which shall be controlled. Being HPLC the most currently instrumental technique used for glucose analysis, the evaporative light scattering detector (ELSD) offers advantages (sensitivity, possibility for operating in gradient mode) over the also used refractive index detector. In this work, an HPLC-ELSD methodology was optimised and validated, aiming the estimate of the uncertainty associated with the results at low levels of concentration of glucose to be measured. Linearity of the response was obtained in the range of glucose concentrations from 20 to 300 mg/L, with an analysis time of 10 min. The global uncertainty was estimated accordingly to the bottom-up approach used by Eurachem. It was 13% on average for concentrations from 100 to 300 mg/L. For lower concentrations, uncertainty increased significantly up to 30% in the vicinity of the LOD of the method.
authors.affiliation: LEPAE, Departamento de Engenharia Química, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, Porto, Portugal.
authors.forename: Berta Nogueiro
authors.initials: BN
authors.lastname: Estevinho
authors.forename: Amélia
authors.initials: A
authors.lastname: Ferraz
authors.forename: Fernando
authors.initials: F
authors.lastname: Rocha
authors.forename: Lúcia
authors.initials: L
authors.lastname: Santos
authors.forename: Arminda
authors.initials: A
authors.lastname: Alves
mesh_terms: D002851:Chromatography, High Pressure Liquid; D005947:Glucose / Q000032:analysis*; D008027:Light; D012542:Scattering, Radiation; D012996:Solutions; D014867:Water / Q000737:chemistry
chemical_list: D012996:Solutions; D014867:Water; D005947:Glucose