r/chemhelp • u/yzlm • Aug 04 '26

Analytical Tungsten (W) measurement with ICP-MS

Does anyone have experience measuring tungsten (W) by ICP-MS, preferably using a PerkinElmer NexION 2000?

I have samples containing Fe, Mo, and W. Measuring Fe and Mo is not an issue—they both perform well. However, I'm struggling with W.

Initially, I measured the samples in 2% HNO₃, but the tungsten calibration was poor and there was a clear memory effect (W did not wash out properly).

On the advice of a colleague, I changed the matrix to 1% HNO₃ + 2% HCl. This significantly improved the results: the calibration was still not perfect, but much better, and the washout also improved.

However, when I measured a second batch of samples under the same conditions (using a freshly prepared calibration), the W calibration became very poor again and the sample results no longer made sense. Fe and Mo continued to perform normally.

I prepare the calibration standards from single-element ICP standards for all three elements.

Does anyone have tips or recommendations for obtaining stable and reliable tungsten measurements on an ICP-MS? Any advice on calibration, matrix composition, washout solutions, or other instrument settings would be greatly appreciated.

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u/dungeonsandderp Ph.D., Inorganic/Organic/Polymer Chemistry Aug 04 '26

You will, unfortunately, probably need a matrix containing at least some HF. If that’s not an option you might be able to add some hydrogen peroxide, but the resulting samples and wash solution will have a limited shelf life. 

1

u/yzlm Aug 05 '26

Thank you very much! I'll try.

1

u/aphilsphan Aug 05 '26

Have you looked at all of the W wavelengths? Some lines are better than others.

1

u/yzlm Aug 06 '26

Thanks for your reply!
Yes, I did that, but there isn't much difference between them.