title: Analysis of saccharides in beverages by HPLC with direct UV detection.
abstract: The present study demonstrates the suitability of direct UV detection for saccharide analysis in HPLC. Under highly alkaline conditions, the non-UV absorbing saccharides are converted by a photo-initiated chemical reaction in the detection cell into malonenolate, which can be detected at 266 nm. A straightforward method for such direct UV detection of saccharides after their separation by anion-exchange chromatography was developed and successfully applied to several beverage samples. Investigation and optimization of the influencing factors using design of experiment resulted in a baseline separation of glucose, fructose, and sucrose within 6 min and LOD values below 0.2 mg L(-1). In addition, a fast, simple and cost-effective flow injection method was developed to estimate the total saccharide concentration. The results of this method applied to beverage samples are in good agreement with the chromatographic method as well as to the saccharide concentration stated by the manufacturer. Finally, a comparison of different commercially available UV detectors and detector cells revealed that sensitive detection requires the use of recently introduced flow cells with extended path length.
authors.affiliation: Institute of Analytical Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria. Thomas.Schmid@jku.at.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmid
authors.affiliation: Institute of Analytical Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Baumann
authors.affiliation: Institute of Analytical Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Himmelsbach
authors.affiliation: Institute of Analytical Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria.
authors.forename: Christian W
authors.initials: CW
authors.lastname: Klampfl
authors.affiliation: Institute of Analytical Chemistry, Johannes Kepler University Linz, Altenberger Straße 69, 4040, Linz, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Buchberger
mesh_terms: D001628:Beverages / Q000032:analysis*; D002241:Carbohydrates / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000191:economics / Q000295:instrumentation*; D004867:Equipment Design; D017022:Flow Injection Analysis / Q000191:economics / Q000295:instrumentation; D005504:Food Analysis / Q000191:economics / Q000295:instrumentation; D057230:Limit of Detection; D014466:Ultraviolet Rays
chemical_list: D002241:Carbohydrates
keywords: Anion-exchange chromatography; Direct UV detection; HPLC; Saccharide