I want to determine TOC and TKN of solid samples. In our analyzer we can analyze only liquid samples. What is the procedure to hydrolyze/digest the sample?
Which acid and its concentration can be used for sample preparation?
I would consult with Harris first but there are other resources online you can find. Usually it's something like 25 mL concentrated sulfuric acid with 1 g solid sample. Usually 7 g or so of potassium sulfate is added along with ~0.8 g CuSO4*5H2O as a catalyst. Then you heat around 350-400 C for 60 min if you're using some sort of bomb apparatus. This is well written in the literature so you should be able to find some kind of procedure for your analysis. You'll want to test in on a standard first to ensure you get 100% recovery then you can apply it to your sample. Hope that helps!
For total Kjeldhal nitrogen the solid sample can first be digested with concentrated sulphurica acid addding a tablet of CuSO4 as catalyst. Digesters are available, for example, u may procure block digester from FOSS or any other availble in the market
Kjeldhal Total nitrogen Method and standard
https://www.ecn.nl/docs/society/horizontal/hor16_nutrient.pdf
http://uwlab.soils.wisc.edu/files/procedures/dnr_totaln.pdf
I hope that can helping you. Thank you have a good day.
Mohamed Adel Ghorab
Dear Selvan..For Total Kjeldahl Nitrogen (TKN) determination you can go through this protocol ...(attachments: IS 7219; Kjeldahl method for protein estimation, Handbook of Kjeldahl ...and FSSAI Lab Manual-1: Milk and milk products ) here all methods on liquid/solid products are explained
There is another document " IDF Bulletin- Comprehensive review of scientific literature on nitrogen protein conversion factor ".., so these will provide u sufficient information.
- Badges
- Science method
- Similar topics
- Chemistry
- General Biochemistry
- Biochemical Techniques
- Analytical Chemistry