170135_inorganicventures_flipping

16.4 ICP-MS Measurement

Resolu'on: Abundance Sensi'vity

• For the quadruple mass filter, the abundance sensi6vi6es for adjacent peaks on the low and high mass are not equal. • This is because the peaks are asymmetric and tend to tail more on the low mass side. • If we have a high concentra6on element with a peak intensity of I h at mass M and want to measure a low concentra6on element with a peak intensity of I L-1 on the low (M-1) mass side or I L+1 on the high (M+1) mass side, the ra6os I L-1 /Ih and I L+1 / I h , are referred to as the low-mass abundance sensi6vity and high-mass abundance sensi6vity, respec6vely.

16.5 ICP-MS Measurement

Resolu'on: Abundance Sensi'vity

• Typical low-mass abundance sensi3vity = 5 x 10-6 • Typical high-mass abundance sensi3vity, = 5 x 10-7

• This means the concentra3ons will be measured to be ~ 0.5 ng/g on the low-mass side and ~ 0.05 ng/g on the high-mass side, adjacent to a mass with a concentra3on of 100 μg/g. • If you are working at dilu3on factors of 10 or greater this translates into significant errors.