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c/hplc·submitted 1 year ago by u/medutest_mel

[Discussion] we are measuring LC-MS at the wrong time and calling it noise

Discussionbranch of 8 comments

I have had 23 orders now and I keep a table, so here is the honest summary rather than a vibe. Material has been consistent. Communication has not. Shipping has varied by about 12 days on nominally the same lane, which matters more in summer than in February. The independent number came back 96.8% against a claimed…

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8 comments, started 1 year ago
u/nora_lundgren30 points·1 year ago

two labs, two different baselines, two different purity numbers, both honest

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u/aksel_kjaer36 points·1 year ago

Injection volume and flow rate? Those affect resolution.

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[removed]17 points·1 year ago

[removed by moderator]

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u/medutest_melOP25 points·1 year ago

The related substances profile is way more interesting than the main peak %. A 98% with 3 peaks is different from a 98% that is one 34% impurity.

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u/medutest_melOP18 points·1 year ago

the gradient is doing the separation work, not the column alone

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u/santiago_villalobos12 points·1 year ago

You have restated the marketing copy. What is the actual substance here.

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u/enzo_petrescu12 points·1 year ago

area% and mass% are not the same and this whole post conflates them

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u/amara_haddad45 points·1 year ago

chromatogram or it did not happen

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