Thanks very much for your suggestions. As per tech support from thermo
fisher, I did full detector set up and calibration and improved and meet
the criteria. Initially the background was around 3 cps it improved to 0.8
Once again thanks all.
On Wed, Jun 27, 2018 at 9:45 AM John Morrison <[log in to unmask]> wrote:
> Hello Prasad,
> How many counts are you seeing at 4.5 and 220?
> If it's a couple of counts then it maybe a tuning issue.
> When did this issue start? Can you revert back to a tune file that gave
> you good background?
> Old cones, even though cleaned, can sometimes give you elevated background
> It's also worth running a Detector Cross Calibration to ensure the
> Discriminator is set correctly.
> John Morrison
> Ionflight LLC
> Ionflight Office Tel: 617-337-5243
> Mobile: 508-821-6333
> Email: [log in to unmask]
> -----Original Message-----
> From: PLASMACHEM-L: Analytical Chem.(ICP's, DCP's, MIP's). <
> [log in to unmask]> On Behalf Of Prasad Lavisetty
> Sent: Tuesday, June 26, 2018 9:10 PM
> To: [log in to unmask]
> Subject: High Background at 4.5 and 220 mass
> We have Thermo IcapQ ICPMS, recently we are facing problems with high
> background at mass 4.5 and 220. The performance at both standard and KED
> modes are failing in background (both mass 4.5 and 220). I cleaned the
> cones, nebulizer and spray chamber. I didn't touch the torch and lens.
> Still the performance is not meeting criteria. Can anybody suggest to solve
> this problem.
> Any suggestions greatly appreciated.
> Prasad Lavisetty
> Scientist, Teva pharmaceuticals, Inc.
> Weston, FL