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6 votes

Examples of compounds that are hard to ionise or which decompose easily upon ionisation in mass-spectrometer

In a sense, everything you put into a mass spectrometer decomposes; the (mass/charge ratio of the) fragments arecactually valuable in distinguishing different isomers. That being so, extensive ...
Oscar Lanzi's user avatar
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5 votes

Programs to view or convert unformatted Mass Spec data

A simple approach can rely on gnuplot, which is freely available at least for the Windows, Mac, and Linux operating system. It is not a dedicated MS program to simulate fragmentation patterns / ...
Buttonwood's user avatar
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4 votes

Are there LCMS compatible buffer systems available for the high pH range 12-14?

First off, as a comment implies you need the right column. Silica-based columns are not suitable for high $\pu{pH}$, even $\pu{pH }8$ can cause problems according to a now-deleted comment in the ...
Oscar Lanzi's user avatar
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4 votes
Accepted

Mass spectrum fragmentation of ethyl acetate

Although EI fragmentation process can often be highly energetic, and as commented can lead to multiple break ups from surplus energy, the highest intensity fragments usually arise from the lowest ...
PLD's user avatar
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3 votes

How to effectively replace DMSO with LC–MS-compatible solvent for the samples from a well plate?

The standard way to remove water and replace with volatile solvents for microscopy is with a dehydration series, e.g., replacing water with ethanol, and then ethanol with acetone. To more thoroughly ...
DrMoishe Pippik's user avatar
3 votes
Accepted

Why is there a [M-1]+ in lieu of a parent signal in the Mass Spectrometry of Primary Alcohol Chains?

One possibility (R = alkyl or hydrogen): $\ce{RCH2 –OH -> RCH=\overset{+}{O}H + H• + e^-},$ where the cation shown is stabilized by the oxygen donating an otherwise nonbonding electron pair to what ...
Oscar Lanzi's user avatar
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3 votes

Mass Spectrometry Resolving Power Normalization to Average Mass

$m / \Delta m$, or the reciprocal of the smallest discernible mass difference $\Delta m$ normalized to average mass $m$. Good question because the resolution in mass spectrometry and chromatography ...
ACR's user avatar
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1 vote
Accepted

How does a fragment with a m/z ratio of 94 form when benzoic acid breaks down?

A subtle hint may lie in the presence of the peak at $28$, which would likely represent carbon monoxide. Carboxylic acids decarboxykate to give $\ce{CO2}$, which can lose an oxygen atom under mass ...
Oscar Lanzi's user avatar
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1 vote

LC-MS/MS analysis of rosuvastatin in rat plasma two peaks

Analysis of biomolecules chromatography can be a challenging exercise because these biomolecules can stick to any fluidic path of the chromatograph if they want to. Just to make sure, is every ...
ACR's user avatar
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