170135_inorganicventures_flipping

16.20 ICP-MS Measurement

Quan%ta%ve Analysis Measurement Techniques - Periodically check the performance of the ICP- MS during the analy:cal 'run

• I prefer to split the sample and spike half of the sample with a known low ppb addi:on of an assortment of analytes ranging from Mg to U. • ABer confirming the calibra:on by analyzing the standards, I like to use an analysis sequence of blank, sample, and sample + spike. • The spike recovery allows me to determine if space charge effects from the matrix element(s) have significantly lowered the analyte signal.

16.21 ICP-MS Measurement

Quan%ta%ve Analysis Measurement Techniques - Standard Addi*ons

• This approach is common with ICP-OES but it may give the analyst a false sense of security when using ICP-MS. It is a concern that this technique has earned such a 'good reputa*on' in view of the fact that it does not guarantee anything except a perfect matrix match. ICP- MS has many more poten*ally serious problems than matrix matching. • The same interference issues discussed above must come into considera*on if you choose to use standard addi*ons. For example, if you have a molecular MO interference before the addi*on and do not use an alternate mass or perform a correc*on, you will s*ll obtain a false high result. • Spend the *me to learn about the matrix and iden*fy poten*al interference issues. AHer you reach a high level of confidence in the iden*fica*on and correc*on for and/or elimina*on of interferences, then the standard addi*ons approach is a convenient way to 'match' a complicated matrix