Total Organic Carbon Analyser

The Shimadzu TOC-V CPN  Dissolved Carbon and Nitrogen Analyser

Location: 1.25a | Member of staff: Dr Steve Boult or Mr Alastair Bewsher

 

The Shimadzu TOC-V CPN Dissolved Carbon and Nitrogen Analyser is used to measure dissolved Carbon and Nitrogen in water samples. Total Carbon (TC) and Total Inorganic Carbon (TIC) can be measured. By subtracting the TIC value from the TC value, the Total Organic Carbon (TOC) can be calculated. Nitrogen can be determined in the same sample as Total N.

Please note: Total N (TN) methodology is still under development

Approx. 15mL of filtered, unacidified sample is required for each analysis. A batch of 25 samples for TOC analysis will take around 9 hours to complete. This includes standards which are analysed as ‘unknowns’ during the run to monitor stability.

Total Carbon (TC) is measured by injecting the sample into the sample port. The port is connected directly to a furnace which is heated to (680°C) All the carbon in the sample is converted to carbon dioxide and is carried in a stream of high purity air to an infra-red detector. The detector produces a signal which is directly proportional to the concentration of carbon dioxide.

Inorganic Carbon (IC) is measured by injecting the sample into the (IC) port. The sample comes into contact with a highly acidic quartz medium. Any inorganic carbon such as carbonate reacts with the acid to produce carbon dioxide. The carbon dioxide is then detected in the same way as previously.

Total Nitrogen (TN) is measured by introducing the sample to a furnace (720°C). The TN in the sample decomposes to Nitrogen Monoxide and is detected by a Chemiluminescence Gas Analyser.

The TOC-V CPN can be used over a range of sensitivities. Typically, a concentration range of 1-300mg/L Carbon can be detected (using the auto-dilution) Calibration is required at the beginning of each session. A minimum of three Calibration standards is recommended for a TC and IC analysis. Typically, the range of concentrations is 1-50mg/L Carbon.

It is expected that the TN Calibration and concentration ranges will be similar to that of TC.

All the data from the analysis is stored on the TOC-V CPN computer and can be converted to a variety of formats (such as Excel).


 
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