The following carbohydrates have been analyzed: glucose,
galactose, raffinose, fructose, mannitol, sorbitol, lactose,
maltose, cellobiose, and sucrose. Food carbohydrates are
characterized by a wide range of chemical reactivity and
molecular size. Because carbohydrates do not possess
chromophores or fluorophores, they cannot be detected
with UV-visible or fluorescence techniques. Nowadays,
however, refractive index detection can be used to detect
concentrations in the low parts per million (ppm) range and
above, whereas electrochemical detection is used in the
analysis of sugars in the low parts per billion (ppb) range.