Micro-Dumas combustion analysis for total carbon and total nitrogen in solid-phase samples (plant tissue, soils, sediments, etc.) is based on transformation to gas phase by extremely rapid and complete flash combustion of the sample material. More details of the process are at Micro-Dumas Overview.
Sample prep considerations
Plant samples must be oven-dried, ball-milled to less than 250 um particle size and weighed (~3 mg, with ug digits significant) into 5 x 5 mm tin capsules before combustion. Poor precision can often be traced to inadequate grinding that leaves fibrous matter or visible granules in the sample. Sample prep for total-C/total-N analysis is here. Clients may send us unprocessed samples (e.g. litterbag contents) or may provide any of the above processing themselves at a major reduction in price.