lower potassium sensitivity

What is your sample matrix? If the sample matrix is relatively clean, you could switch to "cool" plasma conditions, for example lower power and higher neb flow. This should improve the sensitivity for K.

Thank you, Tina, for your quick response. My matrix is digested fats samples diluted to 50X in 50% Nitric acid and 1% HCl. the calibration is done with only 2%HNO3 and 1%HCl. If we lower the power and higher the neb flow, then these changes will affect other elements of interest as well. note please that both boost and snout are ON during the analysis. is there another way to improve the K Without changing aforementioned parameters?

Thanks!

HB

It sounds like your acid matrix is different for your samples (50% nitric and 1% HCl) and standards (2% nitric and 1% HCl). I recommend you match the acid content and/or add an internal standard. The higher the acid concentration, the greater the suppression of the element intensity. 

I think it is chemical interference problem. Potassium is easily ionizable element, ambipolar diffusion will be established which result in K atoms or ions drawn away from central plasma. 

You could try to adjust the observation height (distance from torch and cone) to solve this problem.

Thank you, Tina and Steven, for your feedback.

indeed, I use an internal standard "Y" that shows a good recovery. diluting more the samples will lead to higher reporting limit for many elements of interests.

Steven- does the observation height mean viewing height? is so what is the optimum height for Potassium in aqueous matrix?

Thank you in advance for your assistance!

Best,

Hayat 

You can increase the replicate read time for K in your parameters. If this doesn't work for all of your elements, you can use "Multiple Condition" sets.