Problem with Au Stability in ICP-MS

Hi, I have a problem with Au stability in ICP-MS. I use 10% HCl. I get good calibration curves for other pgm's except for Au which increases with an increase in standards.

How can I overcome this? What's the best argon flow rate I could use? What is the best container for storage and rinsing solution?

Regards Tony

Au can be a real challenge.

We use 5-10% HCl for Au and store it in LDPE. When you mix Au with elements that were in nitric acid you may produce some nitrous oxides that can reduce Au to the metal. Try -first- just putting Au by itself in the 10% HCl and use a LDPE container or other suitable plastic container. You should get good calibration and stability. If this works then the problem may be coming from secondary reactions resulting from the other elements and matrices.

Serving you in chemistry,

Paul R. Gaines, Ph.D.
CEO of Inorganic Ventures & Fellow Chemist

DISCLAIMER: Advice offered by the chemists at Inorganic Ventures is intended for the individual posing the question. Feel free to contact us to verify whether these suggestions apply to your unique circumstances.