Simultaneous determination of ascorbic and dehydroascorbic acids in vegetables and fruits by liquid chromatography with tandem-mass spectrometry

This work describes an analytical method using liquid chromatography coupled with tandem-mass spectrometry (LC-MS/MS) with triple quadrupole in selective reaction monitoring mode for the simultaneous determination of ascorbic acid (AA) and dehydroascorbic acid (DHAA) in pepper, tomato, orange and lemon. The negative ion mode of ESI and MS/MS transitions of m/z 173 -> 143 and m/z 173 -> 71 were used for AA and m/z 175 -> 115 and m/z 175 -> 87 for DHAA. All the validation parameters were found to be within the range of acceptance for both compounds. Different matrix effects were observed in the studied vegetables and samples were quantified by the standard addition approach. The proposed method was suitable for simultaneously determining AA and DHAA with no need for oxidation/reduction or derivatisation steps. The main advantages of this method are its simplicity (little sample preparation), speed (total analysis time does not exceed 5 min) and excellent sensitivity (limits of detection (LODs) of 13 and 11 ng/ml for AA and DHAA, respectively). (C) 2011 Elsevier Ltd. All rights reserved.