Effects Of The Divinylbenzene

Agric. Biol. Chem., 53 (12), 3193-3201, 1989
Effects of the Divinylbenzene Content and Ionic Form of
Cation-exchange Resin on the Chromatographic
Separation of Maltooligosaccharides
Shuji Adachi, Tatsuo Watanabe and Masahiro Kohashi
School of Food and Nutritional Sciences, University of Shizuoka,
395 Yada, Shizuoka 422, Japan
Received May 29, 1989
The distribution coefficients ofmaltooligosaccharides with degrees of polymerization (d.p.) of 1 to
7 on cation-exchange resins (Amberlites HFS-471X and CG-60) with various divinylbenzene (DVB)
contents and alkali-ion forms were determined by the moment analysis of elution curves of the
saccharides. The distribution coefficients were largely dependent on both the DVBcontent and the ionic
form, as well as on d.p. The resin with thehigher DVBcontent gave the smaller coefficient. As the
radius of the hydrated ion became larger, the distribution coefficient wasreduced. The resin-phase
diffusion and axial dispersion coefficients were also determined for maltooligosaccharides with d.p. of 1
to 3. Regardless of the DVBcontent and the ionic form, the resin-phase diffusion coefficient was
correlated with the moleculardiffusivity of each solute by a parallel pore model with a tortuosity factor
of 4.0. The mixing lengths of flow for Amberlites HFS-471Xand CG-60 were 1.9 and 1.5 times as long
as their mean diameters, respectively. Byusing the parameters evaluated, the effects of some operating
variables on the resolution of maltooligosaccharides with d.p. of i and /+ 1 (/= 1 to 6) are discussed.
Gel chromatographicseparation of maltooligosaccharides
has been reported for acrylamide
gels1* and hydrophilic polyvinyl gels2'3)
with small diameters. Although these fine gels
exhibited high resolution, they may be unsuitable
for the separation of saccharides on a
large scale because of their high cost and large
pressure drop. Ion-exchange resins of various
ionic forms have been tested and used forhighperformance
liquid chromatographic analyses
of sugars.4~6) Since these studies have been
performed for analytical purposes, the values
of parameters necessary to predict the elution
profiles under any operating conditions are
not available.
This paper deals with the chromatographic
separation of maltooligosaccharides with degrees
of polymerization (d.p.) of 1 to 7 by
cation-exchange resins witha relatively large
diameter. The distribution coefficients of the
saccharides with d.p. of 1 to 7 to the resins
were determined, and the effects of the divinylbenzene
(DVB)content and alkali-ion form on
the coefficients were examined. The resin-
3193
phase diffusion and axial dispersion coefficients
were also determined for the saccharides
with d.p. of 1 to 3. From these
evaluatedparameters, the effects of some
operating variables on the resolution of saccharides
with d.p. ofi and /+1(7=1 to 6) are
discussed.
Materials and Methods
Ion-exchange resins. Strongly acidic cation-exchange
resins possessing sulphonate groups were used. Amberlite
HFS-471X with different DVBcontents (2, 4, 6 and 8%)
was used in the sodium ion form. Amberlite CG-60.with a
DVBcontent of6% wasused to examine the effect of ionic
form. The resins were kindly presented by Japan Organo
Co. Ltd., and were conditioned to the desired form
according to the standard method.7)
Solutes. Glucose and maltose were purchased from
Kanto Chemicals and Nakarai Chemicals, respectively.
Other maltooligosaccharides were products of Hayashibara
Biochemicals. Dextran T-500 (Pharmacia LKB) with
aweight-average molecular weight of 5.1 x 105 was used
to determine the bed voidage.
3194 S. Adachi, T. Watanabe and M. Kohashi
Properties of ion-exchange resins. The apparent density,
pp, of the resins was measured pycnometrically. The water
regain, Wr, which is defined as the weight of water held in
the wet resin per unit weight of dry resin, was determined
from the difference in weight between...