# Is organic carbon the same thing as organic compounds?

Are they the same thing or is there some minute difference? I have looked all over the web and you would think this would be a common question but I can't find any answer. If they are different then what is the difference?

Thanks

• Organic carbon is the carbon contained in organic compounds. – Ivan Neretin Mar 14 '16 at 7:47
• @IvanNeretin the context of this is for an emissions inventory so I don't think that is quite right – A. Student Mar 14 '16 at 8:07
• Context matters! Plants, animals and atmospheric CO2 are enriched in C-14 compared to e.g. coal deposits. "Organic carbon" might be interpreted as carbon-containing compounds with this particular isotope ratio. – MSalters Mar 14 '16 at 12:01

Organic compounds typically refers to particular, identified compounds and/or compound classes.

Organic carbon, ususally expressed as total organic carbon (TOC), is a relevant term in waste (water) management.

In this context the total carbon (TC) is expressed as the sum of total inorganic carbon (TIC) and total organic carbon (TOC).

TIC and TOC are often measured as the amount of $\ce{CO2}$ liberated from a sample.

UPDATE

While Ivan Netetin's remark on the broader context is certainly true, terms like TOC and COD (in German CSB), the chemical oxygen demand, play an important legal role in the question whether and under which conditions waste water may be submitted to the public sewer systems. This involves water directly from procdution processes, as as the elution of material from from landfills.

In Germany, this is specified in the Abwasserverordnung - AbwV. Here, §6(3) states

Ein nach dieser Verordnung einzuhaltender oder in der wasserrechtlichen Zulassung festgesetzter Wert für den Chemischen Sauerstoffbedarf (CSB) gilt unter Beachtung von Absatz 1 auch als eingehalten, wenn der vierfache Wert des gesamten organisch gebundenen Kohlenstoffs (TOC), bestimmt in Milligramm je Liter, diesen Wert nicht überschreitet.

Translated to non-legalese English, this means: Business-specific limits are considered to be met (= it is legal to submit the water to the sewer) if the fourfold TOC does not exceed the COD given by law.

• Well, it's not necessarily water, but also air and soil. Also, it's not necessarily waste. Organic (as well as inorganic) carbon is found pretty much everywhere, carbon cycle is a huge thing, and human activity is but a small part of it. – Ivan Neretin Mar 14 '16 at 8:43