Hi Myra ... I have a lot of questions! Do you have an AAS available? Can you
give a more detailed report concerning what the matrix (metal and polymer) is,
how it was treated to dissolve the hex. chrome, etc. Also, you did not say
exactly how you treated the extracted sample - what was the final pH, etc. Did
you run a standard curve for hex. chrome? If so what was the maximum
concentration that can be used to give a straight line? Did you use UV or VIS
determination?
I recommend that you first make a 6 point standard hex. chrome curve (including
zero) utilizing the solution that was used for extraction initially. [e.g., 0,
2, 4, 8, 16,and 32 mg/l hex. chrome.] Note: The hex chrome 1000 mg/l standard
solution can be stabilized for a long time by adding NaOH solution to maintain
an alkaline pH of about 9.5 - 10 and keeping it in a polypropylene container.
I will get back to you soon.
John Morico