L. Mansuy et al., Characterization of humic substances in highly polluted river sediments bypyrolysis methylation-gas chromatography-mass spectrometry, ORG GEOCHEM, 32(2), 2001, pp. 223-231
Humic substances were extracted from two sediment cores sampled in a river
on the outskirts of a large city (Deule near Lille, France) and in its high
ly polluted oxbow-lake. Humic acids (HA) were characterized by infrared spe
ctroscopy and in situ pyrolysis/methylation-gas chromatography-mass spectro
metry. The main results are the substantial aliphaticity of HA in the oxbow
-lake at all depths, mainly due to the presence of a lipid fraction associa
ted with the HA structure. The abundance of sterols in this fraction implie
s that lipids could originate from the accumulation of sewage in the oxbow-
lake. Humic acids of the Deule sediments show a different trend; their evol
ution is characterized by a decrease of the pollutant inputs with increasin
g depth. The results demonstrate the efficiency of Py-GC-MS in identifying
the different organic contributions to HA and in distinguishing natural fro
m anthropogenic sources. (C) 2001 Elsevier Science Ltd. All rights reserved
.