For a BS3882 we need to calculate total nitrogen as a percentage of the mass.

We get results by extracting nitrogen 10g of soil in 100ml digestion.

To get from Xmg/l to mg/kg we x10 which I believe right as we take the digestion solution to be a 1:1 l:kg density wise

I am just confused by how to go from 10Xmg/L to the percentage.

Using 1mg/l as an example we get a concentration of 10mg/kg in 10grams of soil

Is it a simple conversion to 10mg in 1000mg giving the percentage as 0.1%