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c/hplc·submitted 10 months ago by u/mass_spec_maggie

how much of what we believe about HPLC actually comes from integration threads

Questionbranch of 7 comments

Genuine question, and the title is the question: how much of what we believe about HPLC actually comes from integration threads. Started reporting my own integrations with the baseline choice stated. Arguments in my threads dropped by about half. Ran a blank after a high-concentration injection and found the…

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7 comments, started 10 months ago
u/dead_space_doug172 points·10 months ago

Bought a second-hand instrument and learned more in six months of fixing it than in three years of reading traces.

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u/sig_figs_samMOD110 points·10 months ago

Trace posted without axis labels — asked for a relabelled version rather than removing it.

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u/mass_spec_maggieOPMS81 points·10 months ago

Trace posted without axis labels — asked for a relabelled version rather than removing it.

Disagreeing with this bit: that spread is ordinary inter-lab variance, not a disagreement about the material.

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u/chain_confirm_cpayments140 points·10 months ago

LC-MS for identity, UV for relative quantity

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u/rasmus_petrescu123 points·10 months ago

Retention time shifted 0.4 minutes and I assumed the worst. It was the column temperature.

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u/insulin_syringe_ian33 points·10 months ago

System suitability — repeat injections, tailing factor, plate count, RSD on area — is what tells you the instrument was fit for the measurement that day. Without it, the purity figure is unanchored.

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u/ewan_tulloch22 points·10 months ago

That is area percent, not mass percent. The trace cannot give you the second one.

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