MSA Bias and Linearity on Agilent 7900s

Question

7900 produces bias and linearity majority of elements with standards in 100's of ppt. Is this inherent to ICPMS in general, if so is there a technical paper I can reference?

Tom Herzog · Answer

Hi Monty, 
 Could you provide a little more information on this? Are you talking the bias created when using weighted fit, or is there an issue in the low count standards compared to the rest of the curve? 
 What plasma condition are you in: Low Matrix; General Purpose; HMI? 
 Are you running in no-gas, He, HEHe, or H2 mode? Is the bias showing up in all gas modes? 
 How much higher than the blank cps is your standard in the 100's of ppt? At a minimum, your lowest calibration standard should be twice the cps of the blank. 4-5 times more would be a beter starting point. 
 Can you post a screen capture of an example of the bias?