Lead in soil sample...
by gasj101010 on 11/24/05 at 00:49:48
I recenlty had a 1g soil sample read via ICP analysis for heavy metal concentrations. I received the results back in ppm. First, note the sample was digested in nitric acid and hydrogen peroxide (and deionized water was added as well)... So the results were run form a soultion not the soil itself. I am not sure if that matters in terms of converting??? But I found that there was 1.79702ppm lead content in the analysis. The EPA suggests that there should be no more than 400mg/kg in the soil. Can anyone help getting from ppm to mg/kg? And do I need to know the density of anything in this sample to figure this out? I did read on one conversion site that I was suppose to convert ppm (units given) to mg/kg (units wanted) by multiplying by 1? But it can't be as easy as multiplying by one in this case as clearly there isn't just 1.79702 mg/kg lead in my soil. Any help would be appreciated! Thanks!!!
Re: Lead in soil sample...
by Robert Fogt on 11/25/05 at 02:19:41
1 mg/kg is indeed 1 ppm
Though the case you bring up is that your lab results are 1.79702 mg of lead per kg of solution. While the EPA is listing a max of 400 mg of lead per kg of soil.
The easiest and safest way may be to contact the lab company, who certainly would have been asked that exact same question before.
If that fails, you could find out the density of the solution then compare that to the density of the soil.
Then again, maybe the EPA used the same type of analysis for their readings and it is 400 mg of lead per kg of solution.