We have been seeing a very high background for silver during analysis. Instrument is a Agilent 7500 ICP-MS with chemstation. The instrument has has a lot of troubleshooting/maintenance and some of the things done include general cleaning ( nebulizer, spray chamber, torch, cones), also put in service new cones, new torch , new o-ring, torch box was replaced, RF generator swapped out a month or so ago (separate issue), thoroughly cleaned the lenses, spent countless hours tuning trying to maximize sensitivity and keep the background low. All the other elements are fine. evening attempted calibrating and analyzing in cool plasma (~ 600 W) versus HOT (1600W). We also have a 7900 series we are planning to swap over to soon and not seeing the same issues. Where could the silver be coming from.