Reference Materials should be chosen based on the type of matrix you are testing. There is no point using brass alloys as a reference if you are a soils lab, or river water samples if you are testing pharmaceuticals.

The RM should be at least the same state of matter as your test matrix (liquid, gas or solid), and the same type of material eg, metal, plant soil, animal tissue, food, etc , and in an ideal world, as similar as possible; same alloy of metal, ocean water vs fresh , plant matter (leaf, grain, fruit) and so on.

That way, when you can get results for the RM that fall within the Uncertainty of Measurement on the RM certificate, you know you have a reasonable chance of having extracted the elements of interest from your samples at the same time.

The way you phrased your question suggests you are asking about the calibration solutions, which is a slightly different proposition. Eventually you will have to combine elements to examine interferences at the relevant wavelengths you choose in the ICPOES. Consult your sales representative to see what combinations of elements x concentrations are most useful to manage interferences in your instrument model.

You can always purchase premixed combinations from external providers with whatever combination of macro and micro elements are most signifcant for your studies.

Dear Matthew Wheal,

Thank you for your prompt response and consideration. There may be uncertainties in the question leading to some misunderstandings, but the point is the following:

We are currently in the procurement phase and we need to know what calibration solutions will be required to avoid possible interference.

What multi-element calibration solutions are required for the elements above? Do we need mono-elemental calibration solutions?

As you can see, the main point is to get a complete package of calibration solutions, since our sales representative cannot provide us properly.

Without knowing your particular sample type and expected concentrations, I would suggest getting a reasonably high concentration that can be diluted to your final working calibration. It is much harder (impossible?) to concentrate a 10 ppm stock up to 1000 ppm, but easy to dilute a 1000ppm stock to 10ppm.

If you can get several multi-mixes that would be good, but if you can only get one multi-mix and supplement it with mono-mix stocks that you combine yourself, then that will also suffice.

There are suppliers other than the manufacturers, try some of the larger scientific suppliers in your region. (I won't mention any names in this forum).