L. Lohse et al., Carbonate removal by acidification causes loss of nitrogenous compounds incontinental margin sediments, MAR CHEM, 69(3-4), 2000, pp. 193-201
This study reports on measurements of organic carbon (C-org) and total nitr
ogen (N-tot) in surface sediments originating from 6 transects along the no
rthwest European continental margin. After elimination of carbonates by an
acidification technique using sulphurous acid, both elements were analysed
in the same sediment sample using an elemental analyser. C-org and N-tot in
the sample were comparatively low, ranging between 1 and 10 mg C and 0.2 t
o 1 mg N g(-1) dry sediment. In a second analysis, the samples were analyse
d without acid addition, resulting in N-tot concentrations of 0-50% higher
compared to their acidified counterparts. As a consequence, molar C/N ratio
s derived from the analysis of C-org and N-tot in the acidified sample rang
ed between 6 to 11, while the N-tot separate analysis reduced C/N ratios to
6 to 8. It is suggested that the addition of sulphurous acid to eliminate
inorganic carbon volatilises nitrogenous organic matter. (C) 2000 Elsevier
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