[stICP]

Hi,
I am starting working with ICP-OES and I have no experience in this field. I must determinate silver and gold in water for injection. I have no idea what the matrix is and what the approximate concentration of these elements in the sample is. Could you help me with this analysis because I haven’t done it before? Could you tell me how can I prepare the sample? Do I have to mineralize the sample? I know that the sample, the standard and the blind must have the same matrix. How can I do that? How can I determinate these elements in the sample? Should I use the axial or radial view on my system (ICP-OES iCAP 7400)- I know that the radial is the best for high concentrations and axial for low concentrations.
I’ll appreciate if someone can push me in the right direction or help me with this challenge (I am not a Chemist). I will appreciate any kind of help.

Thank you

[Corribus]

Your best solution may be to inquire with the instrument manufacturer, as they will have an application specialist on staff who can give you some advice.

As it happens we are doing ICP-OES on both silver and gold at the moment. If your test matrices are already in homogeneous solution, no digestion is required. You just have to acidify them (2-4% nitric as a matrix is typical), match them to your standard matrix, and pull into your instrument. Depending on your concentration, a dilution may be required, but Ag and Au are usually not concentrated, so this probably won't be an issue.

Take care about your internal standard. We found Yttrium to have a fairly significant interference with the strong silver line, so we are using Indium now with better results.

Using standard instrument parameters (no optimization) in axial mode, we get a detection limit for Ag at a few ppb, which is sufficient for our needs. Still working on the gold method, so I can't offer much advice. The general approach would be the same though.