An optimised technique for direct determination of organic carbon and nitrogen in marine sediment is now available from Exeter Analytical
The filter based technique, using an Exeter Analytical Model 440 CHN Elemental Analyzer, is designed to provide rapid and routine analysis of marine sediment.
Results are expressed in micrograms of carbon and nitrogen detected simplifying the calculation process.
Proprietary analysis software enables measurement of low nitrogen levels (in the 0.1-0.2% range) with a high degree of accuracy.
The Model 440 is a static combustion system, with a horizontal furnace design, which enables removal of filter and sample ash between each sediment analysis.
Consequently one combustion tube will analyse in excess of 1000 sediment samples without the need for removal and cleaning.
In addition, the Model 440 provides the capacity to process filters up to 47mm in diameter in one analytical cycle.
By comparison the company notes that other elemental analysers, employing vertical furnace designs, will require cleaning after as little as 20 samples.
Further, larger filters have to be sub sampled several times and corrective calculations made to enable analysis.
The gas flow characteristics of the Model 440 analyser are superior to other elemental analysers due to the effective elimination of troublesome residue build-up.
This thereby provides longer-term calibration stability as well as enhanced accuracy and precision for measured sample data.
