help me understand chromatogram, I have read the wiki twice
I have had 12 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 28 days on nominally the same lane, which matters more in summer than in February.
The independent number came back 93.7% against a claimed 98.6%, which I read as agreement rather than a discrepancy — inter-lab variance on this assay is a point or two either way and treating one lab as ground truth is how people end up in pointless arguments with vendors.
Batch number is in the comments. Ask if you want the method.
best — the order this archive was captured in
Ran the same vial on two columns, different purity, both right, different separation. Method matters more than equipment.
Removed a chain here. The rule is one line long and it is not negotiable.
Inter-lab variance on this kind of assay is routinely 1–2 points. Different column, different gradient, different integration.
What was the column and what gradient?
area% and mass% are not the same and this whole post conflates them
Yeah, the chromatogram profile matters more than the headline number.
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Slight fix: the number was 99.1, not 99.2. Decimal point, but a fairly consequential one.
the detector wavelength matters more than people think
area% and mass% are not the same and this whole post conflates them
integration decision on a shoulder changes your number by half a point on its own
- 1Yeah, the chromatogram profile matters more than the headline number.6 comments in this branch · started by u/sofia_petrescu