The Total Organic Carbon analyzer present at the GI facility is a TOC-L CPH/CPN analyzer (Shimadzu). More (pdf, 14 MB) information on the applications that can be carried out with this specific device. It is utilized to determine the Carbon-Nitrogen content in fluids and sludge.
TOC refers to a Total Organic Carbon analyzer, which utilizes a catalytic oxidation combustion technique at high temperature (the temperature raises up to 720 ºC), to convert organic carbon into CO2. The CO2 generated by oxidation is measured with a Non-dispersive Infra-Red (NDIR) sensor. By using special kits and (dilution) methods the device can be applied to determine the carbon concentration over an extremely broad range (theoretically from 4μg/L to 30 000mg/L), from pure drinking water to sea water with sludge. In addition, it is possible to indirectly determine the fraction of IC (= "inorganic carbon") arising from dissolved CO2 and acid salts containing carbon.
By means of a chemi-luminescence reaction also the nitrogen content can be determined in above mentioned samples. Shimadzu's TNM-1, the Total Nitrogen Module, can accurately measure nitrogen over a broad range: Total Nitrogen (TN) from 100ppb to 4000ppm. A nitrogen-containing sample is combusted to NO and NO2. The reaction products react with ozone to an excited state of NO2. When falling back to the ground level, energy is emitted as light. The nitrogen is measured with a chemi-luminescence detector.
General preparation/submission of samples
The sample flow line diameter is 0.5 mm. Therefore, , in order to prevent clogging, any particle larger than this size should be eliminated from the sample, for example by means of sedimentation.
Check well whether filtered (0.45µm) or unfiltered samples are required
Suspension should be first be treated with a ultra turrax to obtain as fine particles as possible. Discuss the procedure with Paul van der Ven.
Types of C or N analyses and corresponding sample submission
- TC = Total Carbon: all the carbon in the sample, consisting of both inorganic and organic carbon
TC samples: Unfiltered homogeneous (well mixed) samples
- TIC= Total Inorganic Carbon (often referred to as inorganic carbon IC): carbonate, bicarbonate, and dissolvedcarbon dioxide (CO2).
TIC samples: Unfiltered homogeneous (well mixed) samples
- TOC = Total Organic Carbon = TC - TIC: material derived from decaying vegetation, bacterial growth, and metabolic activities of living organisms or chemicals.)
TOC samples: Unfiltered homogeneous (well mixed) samples. Before the actual measurement, samples are acidified and purged to get rid of the TIC.
- NPOC = Non-Purgeable Organic Carbon (commonly referred to as TOC; organic carbon remaining in an acidified sample after purging the sample with gas. See here above)
- DOC = Dissolved Organic Carbon: TOC in a filtered sample.
DOC samples: samples filtered through 0.45 μm pores
- POC = Particulate Organic Carbon = SOC = Suspended Organic Carbon: Carbon present in particles larger than 0.5 mm (on our device)
No POC samples in our current setup
- TN = Total Nitrogen : all nitrogen present in the samples
TN samples: Unfiltered homogeneous (well mixed) samples
- TON = Total Organic Nitrogen: total nitrogen minus the NO3, NO2 and NH4 fraction (to determine on the auto-analyzers).
TON samples: Unfiltered homogeneous (well mixed) samples
- DON = Dissolved Organic Nitrogen: total nitrogen in a filtered sample minus the NO3, NO2 and NH4 fraction (to determine on the auto-analyzers).
DON samples: homogeneous (well mixed) samples filtered through 0.45µm pores.
Location of device
Paul van der Ven
Contact Paul van der Ven long time in advance to discuss the conditions to preparare samples and the details of the analysis methods.