Analytics · Mass spectrometry

Second pass at: MALDI versus ESI for a quick identity check

Analytics › Mass spectrometry MALDI-TOF mass error (ppm) high-resolution MS counter-ion content LC-MS charge states

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Solved by k.okafor in post #3

Tandem mass spectrometry with fragmentation gives sequence information that intact mass cannot. It is the analysis that would actually confirm identity, and it is rarely supplied. Written in the hope of being told what I have missed.

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m.almeidaTL228 Aug 2025#1

Second pass at: MALDI versus ESI for a quick identity check Writing it up because I had to work it out twice and would rather nobody else did.

Something about MALDI versus ESI does not reconcile and I would like a second pair of eyes before I decide which half is wrong.

Two sources, both reputable, giving figures that cannot both be right unless they are measuring different quantities. My suspicion is that they are, and I cannot see how.

3 likes 11mo

LeitermanTL3Regular14 Nov 2025#2

Building on the opening post rather than restating it.

Tandem mass spectrometry: MS/MS fragments the molecular ion and uses fragment masses to confirm identity and detect modifications. A simple identity confirmation by LC-MS does not address post-translational modifications or impurities with the same or very close mass.

0 likes 8mo

k.okaforTL2 Solution9 Jan 2026#3

Tandem mass spectrometry with fragmentation gives sequence information that intact mass cannot. It is the analysis that would actually confirm identity, and it is rarely supplied.

Written in the hope of being told what I have missed.

16 likes 7mo

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