Chemical Forums

Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: Ithakaz on February 21, 2019, 04:30:08 PM

Title: Question about HF on ICP-OES
Post by: Ithakaz on February 21, 2019, 04:30:08 PM

When we determine the composition of metal alloys using ICP-OES that require HF to digest, is it necessary to use the HF-Resistant sample introduction if we are not testing for Si, B or Na?

 Would this cause any damage to the quartz Spray Chamber or torch?

On a related note, for the compositional analysis of AuSn alloys, would a digestion by the use of HBF4 by preferred to an Aqua Regia digestion, due to concerns of Sn stability in Nitric Acid?

Thirdly, would the use of HBF4 also require the use of the HF-Resistant Sample Introduction if we are not testing for Si, B, or Na?

Any thoughts on the use of HBF4 instead of HF when digesting elements that normally require HF?

Title: Re: Question about HF on ICP-OES
Post by: Corribus on February 22, 2019, 08:13:36 AM

Partial answer: if you're using high concentrations of HF, this absolutely can damage instrument hardware. You would preferably need specialized introduction hardware that has glass free parts (e.g., Teflon torch and spray chamber). This requirement is relaxed for HBF4 digestates, which are milder. We frequently do HBF4 digestions and do not swap out the introduction hardware.

Title: Re: Question about HF on ICP-OES
Post by: Ithakaz on February 22, 2019, 10:32:30 AM

Thanks for your response!

The amount of HF would be around 0.04 mL in a 10 mL sample by the time its introduced into the instrument.