[lanrete]

Hi,

I recently bought some Pt cups for my lab for sample evaporation to carry out metallic impurity analysis on the ICP-MS.

However no matter how long i soak the cups in conc HNO3, i am still getting 80-100ppt of metallic impurities from the Pt cups.

Are there any other ways to leach the cups so that i get <10ppt of metallic impurities?

[DevaDevil]

what sample do you evaporate?

and if you dont want any metallic impurities, why use Pt cups? Why not Teflon or KEL-F? (If your temperature needs to be extremely high, I can understand, as these plastics would degrade)

So maybe find a different material that is suited.
Otherwise, you may to live with impurities and take a blank measurement as baseline of it (as the impurities will be a standard error, present in all measurements)