Analysis of carbon, sulfur and nitrogen often provide significant characteristics to environmental samples.
Dissolved carbon can be determined using a Shimadzu TOC-5050A Total Organic Carbon Analyzer. Analysis is based on ignition of micro liter volumes of the sample at 700 °C into carbon dioxide that is measured on line by dedicated infra-red cell. The following forms of carbon can be analyzed:
- Total dissolved inorganic carbon
- Total dissolved carbon
- Total non-purgable carbon
- Other forms of carbon such as total dissolved organic and purgable carbon are obtainable by difference.
Nitrogen species in aqueous samples can be measured as:
- Total Kjeldahl N (TKN)
- Ammonia N (NH4-N)
- Nitrite N (NO2-N)
- Nitrate N (NO3-N)
Nitrogen species are mostly determined by spectrophotometric methods or by ion chromatography.
Sulfur compounds are usually measured as:
- Sulfide by spectrophotometric methods
- Sulfite, thiosulfate and sulfate by ion chromatography
- Persulfate by redox reactions