2.3.6. Monomers composition
Neutral sugars were released by Saeman hydrolysis (Selvendran
et al., 1979) and analysed as their alditol acetates by
gas-liquid chromatography, using a Carlo Erba GC 6000
Vega with a split injector (split ratio 1:50) and an FID detector.
The injector and detector temperatures were 220 and 230
°C, respectively. A DB-225 column (30 m length, 0.25 mm
I.D., and 0.15 μm film thickness) (J&W) was used with H2 as
the carrier gas and a temperature programme between 220 (4
min) and 230 °C (6.5 min), at a rate of 25 °C min–1. Uronic
acids were determined colorimetrically by a modification
(Coimbra et al., 1996) of the method of Blumenkrantz and
Asboe-Hansen (1973).