Thursday, September 17, 2015

Are all ESI/MS instruments the same?

The second paper on my students Jaanus Liigand master’s thesis was published recently. During his master’s he effectively showed that ionization tendencies of analytes in ESI source are independent of the source design and mass analyser of the 
Altogether 15 compounds with varying properties were measured on 5 instruments (here and in Lyon) and two solvent systems. The statistical treatment (t-test and correlation analyses) results showed that there is no reason to expect large variations between analyte responses between instruments.
Importance of this work? (1) Relating ESI/MS responses with analyte properties is possible (we do not have to take into account source or instrument parameters). (2) Ionization efficiencys already available in the literature are universal and can be used by groups having different instrumentation. 
So to return to the original question, of course different instruments have different sensitivity and many of them may work under very different conditions (voltages, gas flow rates and temperatures) but the large picture for ESI/MS ionization stays the same.
Future perspective? Of course different solvent systems have different effect on ionization efficiencies (protonation, adduct formation, etc) and unfortunately scientist can still only generally predict and explain these effects.

No comments:

Post a Comment