Expert: Dr. Henry Boyter, Jr. - 10/16/2006

Question
Hello Sir,

I work as an environmental engineer.

My question is this:

I have been trying to conduct a experiment on the ability of wetland plants to absorb chromium.

I am using Chromium (III) Sulfate as a compound. The thing is that in the Journals I read, Chromium Sulfate concentration is given as 10 mg dm-3. I wanted to know the same concentration in mg/L or mg/ml or some unit that is understandable by the common people. I need help in converting the units to mg/L or mg/ml or any other understandable unit.

My second question is this. Plastic Vials is where I am going to collect my chromium Containing Samples. THe question Is Will the Plastic Vials made up of Polyethylene/Polyethene absorb the Chromium or is it ok to collect the Chromium Containing samples in Plastic Vials?

Thanks for your time and concern, as I will be waiting to hear back from you.

Regards
Manthan

Answer
1 cubic decimeter = 1 L

Chromium water samples are normally collected in HDPE (high density polyethylene).  The key is that the samples are immediately acidified to pH<2.  For another type of plastic or different storage conditions, you would have to run recovery samples.  The samples must be collected by the standards of the government body to which the results will be presented.

http://www.uga.edu/~sisbl/epatab1.html