Organic nitrogen in sediments of the Peru upwelling region

In contrast, organic nitrogen in living organisms is overwhelmingly found in amino acids in proteins and peptides. Petroleum is the result of the maturation of the organic remains of organisms, so what causes the change in nitrogen functionality between organisms and oil, and when does it occur?

Using X-ray photoelectron spectroscopy (XPS) supported by elemental analysis, biochemical analysis, and pyrolysis-gas chromatography with atomic emission detection (py43C-AED) for nitrogen, surface sediments from the Peru upwelling region were shown to contain at least four different organic nitrogen-containing functional groups: amino, pyrrole, pyridine and (tentatively) quaternary nitrogen. The percent in amino groups is at most 40-45%, and possibly as little as 10-15%.