The reductive amination of monosaccharides with 8-aminopyrene-1,3,6-tr
isulfonate (APTS) in seven different organic acids including the commo
nly used acetic acid was investigated by capillary electrophoresis (CE
) with laser-induced fluorescence (LIF) detection. The correlation bet
ween the yields of the saccharide-APTS adducts and pK(a) of the organi
c acid catalyst is consistent with general acid catalysis of the rate-
determining step of the reductive amination reaction. Derivatization i
n the presence of organic acids of higher strength than acetic acid pr
oduced substantially higher yields of APTS-sugar adducts, an effect wh
ich is more pronounced for N-acetylamino sugars. Optimum yields were o
btained using citric acid as a catalyst. Conversion of a few nanomoles
of neutral saccharides to the APTS derivatives is achieved at 75 degr
ees C in less than 60 min.