Cu in KN18 KE12 Lipari

[Ben Buse]

Hi

Has anyone measured Cu in KN18, KE12 or Lipari? Or know of measured values - inc ICPMS, wet chem etc

I seem to be getting the following

KN18 none (-1ppm +/- 3 ppm)
Lipari 20 ppm (+/- 4 ppm)
KE12 none (-7 ppm +/- 3 ppm)

And wondered how compared?

Thanks

ps important not to mount in brass (as SF)