Humic substance hydrolysates
"Bilding blocks"
The HS hydrolysates are probably the end members of the HS continuum, i.e. oxidation or hydrolysis products from humic substances. Further degradation, e.g. by oxidation, leads to the formation of free carboxylic acids. The proportion of HS hydrolysates in natural waters is 10 - 20 % (of all organic components).