Basic Training 4th Annual ICP Conference

16.2 ICP-MS Measurement

Resolution: Equal abundance

The resolution (R) required to resolve 75 As from 40 Ar 35 Cl is 7800:

Mass 75 As = 74.9215955 ; Mass 40 Ar 35 Cl = 74.931236 ; m M

=74.926414 ;

Δm = 0.0096438 R= 74.926414 ÷ 0.0096438 = 7769 or ≈ 7800 This is ~ 26 times greater than the current ‘low resolution’ ICP-MS systems.

16.3 ICP-MS Measurement

Resolu'on: Abundance Sensi'vity

• Having adjacent peaks at the same intensity is not a realis6c or typical situa6on. Therefore, the ability to measure a m/z peak at a low concentra6on adjacent to a high concentra6on m/z peak is a situa6on that must be considered. • This very important considera6on is referenced as Abundance Sensi6vity. The concern is that tailing from the larger peak into the smaller peak will occur, giving false high results for the smaller peak.