2.6. Identity confirmation by MS

For identity confirmation, the MS provides m/z values of ions formed from the analyte molecules and relative abundancies of the ions. Validation guidelines by SANTE/SANCO [ref 4] and European Commission Decision 2002/657/EC [ref 5] are the most specific with respect to using MS data for identity confirmation and are recommended by the authors of this course. In the rest of this chapter we rely on these two validation guidelines.
For comparison, reference mass spectra should be recorded on the same instrument and using the same operating mode as used for the sample analysis. Preferably, reference spectra should be recorded within the same analysis batch as the samples.
Recommendations for choosing good diagnostic (characteristic) ions:

• The quasimolecular ion should be involved in identification.
• High m/z (m/z > 100) ions are more specific than low m/z ions.
• Product ions which lose (eg H₂O or NH₃) are of little diagnostic value.
• The choice of diagnostic ions depends on matrix interferences.

The usage of principles outlined in this section is illustrated in section 2.7.

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Identity confirmation by MS

http://www.uttv.ee/naita?id=23688

https://www.youtube.com/watch?v=G2IISK_yM0s

The usage of principles outlined in the above video are illustrated in section 2.7.