Nitrogen natural organics

Obviously, it is actually the total organic mass consisting of carbon, hydrogen, oxygen, nitrogen, etc. within the solid phase that acts to sorb the chemical of interest (i.e., the fom in kg om kg-1 solid). Natural organic matter is typically made up of about half carbon (40 to 60% carbon) hence, fom approximately equals 2-f and these two metrics are reasonably correlated. 

Cocaine is the most potent naturally occurring stimulant. It is found as an alkaloid (nitrogen-containing organic base) in the leaves of the Erythroxylon coca trees in the Andes Mountains. Coca leaves contain 0.5-1.8% cocaine (benzoylmethylecgonine or BZ) that can be refined to nearly 100% purity. Research indicates that the plant produces cocaine to kill insects that prey on it. In humans, it is a central nervous system (CNS) stimulant. 

Psilocybin is a naturally occurring hallucinogen. It exerts neurotoxic effects similar to LSD and has a chemical structure similar to the neurotransmitter serotonin in the human brain. Psilocybin is found as an indole alkaloid (nitrogen-containing organic base) in the fungal (Protista) kingdom. Often it is accompanied by the related alkaloids, psilocin, baeocystin, and norbaeocystin. 

Berwick, L., Greenwood, P., Kagi, R., and Croue, J. P. (2007). Thermal release of nitrogen organics from natural organic matter using micro scale sealed vessel pyrolysis. Org. Geochem. 38,1073-1090. 

The Michaelis-Menten equation is often employed in soil-water systems to describe kinetics of ion uptake by plant roots and microbial cells, as well as microbial degradation-transformation of organics (e.g., pesticides, industrial organics, nitrogen, sulfur, and natural organics) and oxidation or reduction of metals or metalloids. Derivation of the Michaelis-Menten equation(s) is demonstrated below. 

Nasholm, T., Ekblad, A., Nordin, A. et al. (1998). Boreal forest plants take up organic nitrogen. Nature, 392, 914-16. 

Starch, as ordinarily prepared either in the laboratory or commercially, requires very little additional purification. It is one of the few natural organic substances that can be obtained readily in a high state of purity. A typical analysis of a standard grade of commercial corn starch shows that it contains, on a dry basis, approximately 99.0% starch, 0.05-0.07% nitrogen, 0.02% phosphorus, 0.08-0.10% ash, and 0.5-1.0% fatty substance. Normally, the starch contains 10-12% moisture. The fatty material and a part of the phosphorus can be removed by extraction with 85% methanol - - or by extraction with ethanol containing a small amount of nitric acid, although the latter treatment may cause some degradation of the starch. 

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