gradient

three years of gradient threads, summarised so you do not have to read them, which sounds obvious until you try to state the evidence for it. Carryover from a previous…

we are measuring method development at the wrong time and calling it noise. I have gone back and forth on this for months. Why two honest labs report different numbers…

the LC-MS question that gets asked weekly, answered properly, which sounds obvious until you try to state the evidence for it. WWB sent me the column, the gradient and…

LC-MS confirmed identity but the UV purity is 94%. now what, and before anyone asks: same batch throughout, single submission, no cherry-picking between services. The…

LC-MS is doing more work than we give it credit for, and I am aware this is a minority view on this board. Why two honest labs report different numbers on the same…

reading gradient threads from 2024 and half of it aged badly. It is the sort of thing everyone half-believes and nobody writes down. Resolution between two peaks…

proposal — a flair for integration posts. Comments open, and the wording is genuinely up for discussion. UV response is not uniform across species. At 214nm you are…

is 98.1% actually fine or am I being sold a rounding error, and before anyone asks: same batch throughout, single submission, no cherry-picking between services. The…

reading chromatogram threads from 2024 and half of it aged badly — a position I have arrived at slowly and would like tested. Retention time shifted 0.4 minutes and I…

proposal — a flair for HPLC posts. This affects how posts get sorted and removed, so it belongs in the open. Chased a ghost peak for three weeks. It was the plumbing.…

Slightly embarrassed to be asking this, but: someone explain purity to me like I have not read a paper in years. Sent the same vial to Janoshik and VendorInvestigate.…

does integration actually matter or is it forum lore at this point. I am not trying to be the "source?" guy. I would just like a source. System suitability — repeat…

unpopular opinion: most of what gets said here about integration is guesswork. Not a hot take, just something I have not seen said plainly here. Chased a ghost peak for…

genuine question about method development that I am slightly embarrassed to ask. Searched first, found three threads that contradict each other, hence the post.…

HPLC — what am I missing here. I would rather ask a basic question now than get this wrong quietly for two months. Chased a ghost peak for three weeks. It was the…

Not naming the poster, the trace is in the thread below this one and they will know. The reported figure is 98.47%. The baseline in the attached trace drifts visibly…

does LC-MS actually matter or is it forum lore at this point. I am not trying to be the "source?" guy. I would just like a source. Gave the same trace to two people I…

the gradient rule is doing its job and people should stop complaining. Nothing about this affects the ranking maths, before anyone asks. Reading a trace posted here, in…

can we stop arguing about method development until somebody posts a number. I am not trying to be the "source?" guy. I would just like a source. System suitability —…

chromatogram is not what most of this community thinks it is. Two minutes of reading now saves an argument later. Started reporting my own integrations with the…

help me understand gradient, I have read the wiki twice, and I want the answer with the reasoning attached rather than just the conclusion. Why two honest labs report…

Right: split one vial across VendorInvestigate and PeptideMeter — 94.2% and 93.7%. I paid for this one myself, nobody sent me anything, and the receipts are in the…

The one-line version is the title: integration decisions change your number more than the sample does. The rest is why. Carryover from a previous high-concentration…

method development — 10 things I got wrong before I got it right. Change my mind, genuinely — I have no stake in being right about this. Bought a second-hand instrument…

Asking properly rather than in a comment on somebody else’s thread: gradient — what am I missing here. A shoulder that does not baseline-resolve cannot be quantified…