Hello,
I am performing compositional analysis of biochar (using ICP-OES), I've used digestion in using Nitric Acid (HNO3) and Hydrofluoric Acid (HF).
The extract that I've obtained is not transparent (charged with pigments), as is shown in the picture below.
In literature, they used the same method, or replacing Hydrofluoric Acid with Perchloric Acid (HClO4), some others used biochar ash for digestion.
- How should the digestion be done in a biochar case?
- For those solutions, what can we do for make them less dark?
Any comment or insight would be appreciated!!