I've spent 12 weeks collecting 74 public COAs from 9 vendors. I log lab name, batch ID, test date, HPLC purity, mass spec, and whether the PDF is editable.
So far 28/74 lack a batch ID, 17/74 list a lab that doesn't show up on the accreditation registry, and 11/74 have purity above 99.5% but no chromatogram. I'm not naming vendors. Is this just normal sloppy marketing, or a useful red-flag score? What fields do you track?
Check PDF author fields. Swapped logos often keep old metadata.
I took your PDF metadata tip and checked 12 files. Six had author names from a totally different vendor, three had no producer at all. Now I log author, creator, and mod date. Quietly fascinating. Batch IDs still missing on the same old flyers.
Metadata is the receipt nobody meant to leave.
I track: lab, batch, test date, HPLC, MS, chromatogram attached, accreditation match, PDF author, and vendor SKU. 74 COAs is a solid sample. 38% missing batch ID feels less like sloppy marketing and more like a pattern worth scoring.
I only count a batch ID if it matches something on the vendor site or invoice. Otherwise it's just a sticker. My log has a column for 'verifiable?' and it's depressing how empty it gets.
Accreditation registry mismatches are my biggest pause. Labs move, rename, or get acquired, so I note the search date. If the lab isn't listed then and there, I tag it. No drama, just dates.
Editable PDFs with swapped logos are exactly why I screenshot the COA and hash the file. If the metadata changes later, I want to know. Twelve weeks in, my folder is messy but honest.
Matches what I found — 38% missing batch IDs seems to be the norm here, not the exception.
I logged the boring axis instead — test date versus the day it landed on my porch — and over 23 orders across 9 months the median lag was 5 months, with an ugly outlier at 14. That lag tells you more about a vendor's actual cadence than a missing field does, because a COA can be perfectly formatted and still describe a batch that was gone before you ordered.
Weirdest part of my own sheet: the three vendors with the cleanest, prettiest COAs were the ones whose "same bach ID" numbers drifted between orders — 99.2% in March, 98.1% by July, same batch, same lab name. So I flipped from scoring vendors to scoring batch-level consistency, and my tier list rearranged completely.
Curious whether your 74 include repeat batches from the same vendor, because that's where I'd expect the real tells to hide.
I started logging the COA’s sample receipt date vs. release date, not just test date. A few had a 6-week gap, which made me wonder if the vial was from an older run.
I also check whether the batch ID format actually matches the vial label—some COAs use order numbers that look like batches but aren’t. Did you track method/SOP numbers? That’s been my quickest “generic template” tell. I do it in 30 seconds between snack refills, just a phone note.
I started logging a different column: whether the COA separates “purity” from “peptide content.” A 99.5% area peak can still be mostly salts/water by mass, and most of the PDFs I’ve seen don’t break that out.
3am spreadsheet brain here: new column idea — check the PDF metadata (creator, mod date) against the test date. i pulled 20 COAs for my own sheet and 9 had mod dates weeks after the test date, plus 4 chromatograms were just pasted jpegs, not embedded data.
also started scanning the QR/verify link: if it doesn't resolve to that exact batch id, it's basically decorative. did you log whether the mass spec has annotated peaks or just a screenshot? that's where i keep finding fluff.
I'm one week in and still googling COA, y'all are amazing 😅
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