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c/hplc·submitted 9 months ago by u/bilal_adebayo

three years of LC-MS threads, summarised so you do not have to read them

Labbranch of 9 comments

three years of LC-MS threads, summarised so you do not have to read them — a position I have arrived at slowly and would like tested. A shoulder that does not baseline-resolve cannot be quantified honestly. You can report it as an unresolved shoulder, which is useful information, or you can develop the method until…

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9 comments, started 9 months ago
u/hugo_bergstrom1 point·9 months ago

Mass spectrometry answers identity. UV purity answers relative quantity under the run conditions. A document with one and not the other is answering half the question, and the half it answers should be stated.

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u/step_count_stan1 point·9 months ago

Did you run a blank between injections?

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u/hedda_ekstrom1 point·9 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/egfr_watcher2 points·9 months ago

axis labels or the trace is decoration

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u/bilal_adebayoOP1 point·9 months ago

How old is the column and roughly how many injections has it seen?

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u/rasmus_petrescu-27 points·9 months ago

Not convinced by that integration. Dropping the baseline there absorbs part of the shoulder into the main peak.

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u/valeria_cardoso-38 points·9 months ago

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

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u/cormac_roos1 point·9 months ago

Yes — system suitability first. Without it the number is an assertion about the instrument, not the sample.

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u/erez_yilmaz1 point·9 months ago

Is that baseline drawn by the software or by hand?

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