Nickel Issues ICP-MS 7800

Hello,

I see calibration level 1(1ppb) have a calculated concentration of -0.183 ppb, so the calibration isn't oke. maybe your calibration blank is contaminated or have you used a different batch acid for the blank.

Lines 3-5 (blank, blank, 1/100ppb) make me think there is a contamination issue.

Check the cps of Ni on those first 4 blanks. If you see a downward trend, that could be an indication of a Nickel contamination somewhere in the instrument that is washing out. If they are all relatively equal, the blank solution itself may be contaminated.

It's most likely that this Ni contamination is caused by the Ni (plated) cones. Especially the skimmer cone could cause this. This contamination level is higher if the carbon content in the matrix is higher or the concentration of acid is higher. If an new skimmer (or skimmer and sample) cone is used then the cps in the blank (contamination level) is dropping. If it's not possible to get rid of the carbon or high acid concentrations and the contamination is to high then is good to use the Pt tipped cones with the brass skimmer base.

Cheers,

Edgar

Sometimes I have this problem too even after cleaning the cone. 

Try to clean the cone with citranox chemical detergent and aluminium powder. Before running samples, conditioning your cone with 50mg/L Ca in 1% HNO3 then rining 1% HNO3 around 20mins.

Hope it is helpful.