<p>If the "C" stands for carbon,  then the "unit" doesn't conform to the SI standard, which states that units should not contain extraneous information. That information should instead be in the name of the relevant quantity. See <a href="http://physics.nist.gov/Pubs/SP811/sec07.html" rel="nofollow">http://physics.nist.gov/Pubs/SP811/sec07.html</a> for more information. </p>

CC BY-SA 3.0
2014-06-30T03:54:31.233Z
The litre isn't an SI unit either. SI units of volume are based on lengths cubed. The correct SI unit would be `g/m3 carbon (in water!)`. `mg/dm3` is also a common substiute for `mg/L` in laboratory work because a m3 of water just seems an absurdly large quantity. As they've already broken another guideline of the referenced style guide, it's not surprising that they chose something that scans better in English `mg C L-1` over the slightly less natural `mgL-1 C (in H2O)`. Note also that their ordering avoids the need to laboriously point out that we're talking about litres of water, not carbon
Level River St
CC BY-SA 3.0
2014-06-30T06:57:03.417Z
@steveverrill I think kg/m³ would actually be the strict SI formulation, since the kg is the base unit of mass in SI (despite having a prefix!). In any case, it's pretty common in my experience for publications to deviate from strict SI.
Pont
CC BY-SA 3.0
2014-06-30T02:36:32.210Z
2014-06-30T02:36:32.210Z
Steve Emmerson
<p>Given the subject matter of the paper, I'd assume that it stands for carbon, and the whole expression refers to milligrams of carbon (or organic carbon) per litre of lake water.</p>

CC BY-SA 3.0
2014-06-29T19:08:44.973Z
2014-06-29T19:08:44.973Z
Pont
<p>Could somebody tell me what the "C" signifies in the unit mg C L<sup>-1</sup>? I was wondering if it stood for concentration but it seems redundant as litres are mentioned. Thanks.</p>

<p>The paper which uses the unit is "Dissolved Organic Carbon Thresholds Affect Mercury Bioaccumulation in Arctic Lakes" by French et al. 2014.</p>

CC BY-SA 3.0
2014-06-30T00:01:32.947Z
Likely they are specifying carbon in units milligram per liter.
casey
<hydrology><terminology>
Meaning of the C in the unit "mg C L-1"
Bprodz
# Meaning of the C in the unit "mg C L-1"

(Asked by: username_0 on 2014-06-29)

Could somebody tell me what the "C" signifies in the unit mg C L-1? I was wondering if it stood for concentration but it seems redundant as litres are mentioned. Thanks.

The paper which uses the unit is "Dissolved Organic Carbon Thresholds Affect Mercury Bioaccumulation in Arctic Lakes" by French et al. 2014.

**Tags:** hydrology, terminology

> **Comments:**
> **username_1**: Likely they are specifying carbon in units milligram per liter.  

---

## 2 answers

### Answer by username_4 on 2014-06-29. Score: 11 | Accepted answer

Given the subject matter of the paper, I'd assume that it stands for carbon, and the whole expression refers to milligrams of carbon (or organic carbon) per litre of lake water.


---

### Answer by username_2 on 2014-06-30. Score: 3

If the "C" stands for carbon, then the "unit" doesn't conform to the SI standard, which states that units should not contain extraneous information. That information should instead be in the name of the relevant quantity. See <http://physics.nist.gov/Pubs/SP811/sec07.html> for more information.

> **Comments:**
> **username_3**: The litre isn't an SI unit either. SI units of volume are based on lengths cubed. The correct SI unit would be `g/m3 carbon (in water!)`. `mg/dm3` is also a common substiute for `mg/L` in laboratory work because a m3 of water just seems an absurdly large quantity. As they've already broken another guideline of the referenced style guide, it's not surprising that they chose something that scans better in English `mg C L-1` over the slightly less natural `mgL-1 C (in H2O)`. Note also that their ordering avoids the need to laboriously point out that we're talking about litres of water, not carbon  
> **username_4**: @steveverrill I think kg/m³ would actually be the strict SI formulation, since the kg is the base unit of mass in SI (despite having a prefix!). In any case, it's pretty common in my experience for publications to deviate from strict SI.  

---

