Aliphatic amines in Chesapeake Bay sediments

Aliphatic amines were determined in sediments and sediment pore waters from several contrasting sites in Chesapeake Bay. The aliphatic amines diethylamine, sec-butylamine, n-propylamine, and i-propylamine were detected in a limited number of pore-water samples at concentrations generally less than ˜ 0.6 μM. The occurrence of these amines showed no obvious correlation to other sediment geochemical parameters. Whole sediment (HF/HCl-extractable) aliphatic amines were less than ˜ 0.8 nmol/gdw. Isoamylamine and 2-methylbutylamine were the only amines that could be detected and quantified in sediment extracts, although diethylamine was below our detection limit in selected samples. When compared to other measured nitrogen pools in the sediments, these observations suggested that aliphatic amines may not represent a significant fraction of the nitrogen that is remineralized in these sediments, although more detailed concentration and rate studies are needed to verify their role in sediment nitrogen cycling. These aliphatic amines also did not appear to represent a major component of the uncharacterized nitrogen in these sediments.