Analytica Chimica Acta 398 (1999) 111–122
Degradation of cellulosic materials under the alkaline conditions of a
cementitious repository for low and intermediate level radioactive waste
Part I: Identification of degradation products
M.A. Glaus
a,∗
, L.R. van Loon
a
, S. Achatz
1, b
, A. Chodura
2, b,c
, K. Fischer
b,c
a
Waste Management Laboratory, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
b
University of Trier, Department of Inorganic and Analytical Chemistry, Universitätsring 15, D-54286 Trier, Germany
c
GSF-National Research Center for Environment and Health, Institute of Ecological Chemistry, Ingolstaedter Landstr. 1, D-85764
Neuherberg, Germany
Received 10 December 1998; received in revised form 15 April 1999; accepted 26 April 1999
Abstract
In order to assess the potential role of cellulose degradation products as metal-binding chelates in a repository for radioactive
waste, different cellulosic materials (pure cellulose, cotton, tissues and recycling paper) were degraded under the chemical
conditions of cement pore water (pH 13.3). The degradation products formed were characterised using different separation
techniques (HPIEC, HPAEC, GC-MS, MS/MS) and by high resolution
1
H-NMR spectroscopy. The main degradation products
of pure cellulose are the diastereomeric -isosaccharinic acid (-ISA) and -isosaccharinic acid (-ISA), which accounted
for ∼80% of total dissolved organic carbon formed. Minor components are short chain aliphatic acids such as formic acid,
acetic acid, lactic acid and threonic acid comprising less than 10% of total dissolved organic carbon. The degradation of the
other cellulosic materials resulted in lower amounts of -ISA and -ISA and in higher yields of small organic acids (acetic
acid) and of unidentified compounds. The combination of the different MS and NMR techniques unequivocally shows the
structural identity of -ISA. ©1999 Elsevier Science B.V. All rights reserved.
Keywords: Cellulose degradation; Characterisation; Isosaccharinic acid; Ion exclusion chromatography; GC-MS;
1
H-NMR
1. Introduction
The effect of organic substances on the mobil-
ity of radionuclides must be investigated as part of
∗
Corresponding author. Tel.: +41-56-310-22-93; fax: +41-56-
310-22-05
E-mail address: martin.glaus@psi.ch (M.A. Glaus)
1
Present address: GSF-National Research Center for Environ-
ment and Health, Institute of Ecological Chemistry, Ingolstaedter
Landstr. 1, D-85764 Neuherberg, Germany.
2
Present address: Sakosta GmbH, Schnickstr. 22, D-60314 Frank-
furt, Germany.
safety assessment of a deep underground reposi-
tory for radioactive waste [1]. The identification of
strong ligands present either in the waste or formed
from waste materials by chemical transformations,
is an important task in this context [2]. Strongly
complexing ligands interact with radionuclides caus-
ing desorption from the engineered barrier system
of the repository. The mobility of the radionuclides
might thereby be increased compared to a situation
in which no ligands are present, so that a faster
transport of the radionuclides to the biosphere could
occur.
0003-2670/99/$ – see front matter ©1999 Elsevier Science B.V. All rights reserved.
PII:S0003-2670(99)00371-2