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Investigation of photochemical reaction products of glucose formed during direct UV detection in CE
Author(s) -
Schmid Thomas,
Himmelsbach Markus,
Buchberger Wolfgang W.
Publication year - 2016
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201500283
Subject(s) - chemistry , irradiation , aldehyde , photochemistry , chromatography , organic chemistry , catalysis , physics , nuclear physics
In CE, saccharides are accessible to direct UV detection due to a photochemical reaction in the detection window of the separation capillary resulting in the formation of UV absorbing substances. Employing a CE method that allows long in‐capillary irradiation with subsequent UV and MS detection, the present study could identify several reaction products of glucose. Among these were UV absorbing substances so far unknown to be formed during direct UV detection with the chemical formulas C 4 H 6 O 2 , C 5 H 6 O 4 , C 5 H 8 O 3, and C 6 H 8 O 5 . Investigations of the impact of the irradiation time revealed differences between these reaction products suggesting differing reaction mechanisms especially for the smallest products. More detailed information could be obtained by experiments with isotope‐labeled substrates performed to determine the parts of glucose that are converted to the particular reaction products. In addition, structural formulas for the reaction products were suggested based on HPLC‐MS/MS measurements of off‐line irradiated glucose solutions which revealed the existence of functional groups such as carboxylic acid or aldehyde groups.