u/first_hundred
Member #63. The c/coa rules were my idea and I regret nothing.
long-standing contributor · joined 19 Aug 2023
Comments — page 3 of 3
comment on [Lab] split one vial across VendorInvestigate and PeptideMeter — 97.2% and 98.4% in c/coa · 419 points · 1 year ago
Does the lot on the vial match the lot on the page?
comment on [Lab] split one vial across VendorInvestigate and PeptideMeter — 97.2% and 98.4% in c/coa · 358 points · 1 year ago
How to ask for a batch record without it turning into a negotiation.
One email, three requests: the batch-specific certificate for lot X, the method line behind it, and the storage condition the stability statement was written against. No preamble, no explanation of why you want it.
What comes back is the signal. A full document with the column and gradient printed on it, inside a day, tells you there is a real quality system behind the operation. That is the test I run before I order from anyone new, and it costs nothing.
comment on how much of what we believe about gradient actually comes from purity threads in c/hplc · 138 points · 1 year ago
Push back: a longer run is not automatically better resolution. You are trading peak width for time and the ratio is what matters.
comment on help me understand method development, I have read the wiki twice in c/hplc · 135 points · 2 years ago
system suitability before you believe any number on the run
comment on help me understand SURMOUNT, I have read the wiki twice in c/trialwatch · 288 points · 2 years ago
Intention-to-treat analyses everybody randomised regardless of what they did afterwards. Completer analyses only those who finished. The second is systematically more flattering and both are legitimate if labelled.
comment on [Discussion] the method development advice in here is 2 years out of date in c/hplc · 13 points · 2 years ago
What did system suitability look like on that sequence?
comment on [Question] purity — what am I missing here in c/coa · 119 points · 2 years ago
Your name and address edited out of the screenshot above. The batch details are untouched and should stay.
comment on [Lab] 16th independent test on ERP — 97.4% on a claimed 97.0%, and the trend is the interesting part in c/hplc · 194 points · 2 years ago
Area percent is the integrated area of your peak over the total integrated area at one wavelength on one gradient.
This is the whole methodological point of the board in one line.
comment on how much of what we believe about COA actually comes from area percent threads in c/coa · 71 points · 2 years ago
Removed — cropped document. Post the whole page or do not post it; the fields people crop are the fields that matter.
comment on integration — 17 things I got wrong before I got it right in c/hplc · 1 points · 2 years ago
Push back: a longer run is not automatically better resolution. You are trading peak width for time and the ratio is what matters.
comment on [Lab] 16th independent test on WXT — 99.3% on a claimed 98.5%, and the trend is the interesting part in c/coa · 17 points · 2 years ago
Left up and flaired Explainer. This is the answer we keep linking, written properly.
comment on [Question] COA — what am I missing here in c/coa · 198 points · 2 years ago
Your name and address edited out of the screenshot above. The batch details are untouched and should stay.