Humic substances in the nitrogen cycle of polar waters. A comparison between the Arctic and Antarctic

LARA, RUBÉN JOSÉ; KATTNER, GERHARD

Humic substances in the global environment and implications on human health

Elsevier

Lugar: Amsterdam; Año: 1994; p. 799 - 804

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0pt; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> The contribution of humic substances to the dissolved nitrogen pool in Antarctic and Arctic waters is compared. Average dissolved organic nitrogen (DON) concentrations were similar in both regions (3-4 µM N). XAD-2 fractionation of dissolved organic matter showed that the hydrophobic acid fraction accounted for 20% of DON in the Antarctic (mean: 0.69 µM N) and 19% in the Arctic (mean: 0.77 µM N). The hydrophobic neutral fraction was 15% of DON in the Antartic (mean: 0.5 µM N) and 25% in the Arctic (mean: 1.0 µM N). The hydrophiIic fraction was ca. 60% of DON.