title: Determination of isoascorbic acid in fish tissue by hydrophilic interaction liquid chromatography-ultraviolet detection.
abstract: A new hydrophilic interaction liquid chromatographic (HILIC) method for the simultaneous determination of isoascorbic (IAA) and ascorbic acid (AA) was developed. The separation of IAA and AA was studied in various HILIC stationary phases and the influence of the composition of the mobile phase, the ionic strength and the column temperature to the chromatographic characteristics is presented. The final method used an aminopropyl column under isocratic elution with acetonitrile-100 mM ammonium acetate solution (90:10, v/v) at a flow rate of 0.4 mL/min and a detection wavelength of 240 nm. This method was validated and the calibration curves were found to be linear in the range of 1.0-65 microg/mL for both IAA and AA. The method limit of detection for IAA determination in fish tissue was 2.3 microg/g. Inter-day precision (as %RSD(R)) was ranged between 0.56% and 8.3% at three concentration levels, whereas the respected recoveries ranged between 82% and 98%. This method was applied to the determination of IAA (as additive E315) in frozen redfish samples. The hyphenation of the HILIC separation with a tandem mass spectrometer was also studied and the problems encountered with negative electrospray ionization under HILIC separation conditions are discussed.
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece.
authors.forename: Spyros
authors.initials: S
authors.lastname: Drivelos
authors.forename: Marilena E
authors.initials: ME
authors.lastname: Dasenaki
authors.forename: Nikolaos S
authors.initials: NS
authors.lastname: Thomaidis
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000032:analysis; D001205:Ascorbic Acid / Q000032:analysis*; D002138:Calibration; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D005399:Fishes; D057230:Limit of Detection; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry
chemical_list: D000975:Antioxidants; C005056:isoascorbic acid; D001205:Ascorbic Acid