When you are running the P/A tuning solution on the 7900 ICP-MS do you select all the masses in the P/A tune solution or do you just use the masses form the method that you are using.
The p/a tuning applies for the elements in the method that could be run above the pulse measurement. So if only the elements in the method are selected in the p/a tuning it should be enough. Running more elements, beside the elements of intrest, in the p/a adjustment makes the quality in general not beter. The p/a factor adjustment in the batch, that run automatically the p/a factor, is also a very good, automated and fast tool to adjust the p/a factor for the elements of intrest.