Bioequivalence and Bioavailability Forum

Dear Compliance,

If you change between two different principles of ion source (e.g. ESI and APCI): matrix effects will be totally different. The principle of ionisation is totally different between ESI (ionisation in the liquid phase, then evaporation of ions into the gas phase) and APCI (evaporation, then ionisation in the gas phase). APCI is far less sensitive to matrix effects. In APCI you sometimes have ion enhancement, not just ion suppression (enhancement is not frequent in ESI).

If you change between two different types, with the same principle (between 2 ESI sources, or 2 APCI sources, for instance between an API 3000 and an API 4000, or between Sciex and Micromass): you can still get differences in matrix effects, due to differences in the geometry of the source, in the capillary, shape of the spray, design of the cone... For one molecule you can have a strong ion suppression with one source, and less problems with the other; for the next molecule it may be the other way ! It is very difficult to predict.

So to summarise:

❝ Kindly let me have some idea about how the change in ion source affect the matrix effect?

You have to try and see !

Regards
Ohlbe