u/column_dead_volume
Your ghost peak is plumbing, not product.
member · joined 9 Sep 2024
comment on peak at 4.2 min, nobody can tell me what it is, ideas in c/hplc · 234 points · 2 days ago
There it is. That is your benzyl alcohol. Redissolve dry powder in mobile phase and the peak will vanish.
comment on bought a second-hand HPLC. worst best decision of my life. AMA in c/hplc · 121 points · 3 days ago
the crying is the plumbing. it is always the plumbing. every ghost peak i have ever chased was a fitting.
comment on peak at 4.2 min, nobody can tell me what it is, ideas in c/hplc · 267 points · 3 days ago
4.2 min on that gradient is very early — you are basically still at 20% organic. That is where you find things that barely retain on C18: salts, small polar fragments, excipients, and occasionally the preservative if the vial was reconstituted.
Was it? Because benzyl alcohol elutes early and 0.9% of total area would not be surprising if you injected a reconstituted sample rather than redissolving powder in mobile phase.
comment on [Results] perimenopause, 18 months, and why the usual advice failed me in c/glp1women · 1 points · 8 days ago
Yeah, perimenopause is under-researched.
comment on how many independent tests before you trust a vendor. my number is three in c/vendorvetting · 0 points · 8 days ago
the Janoshik result being close to the claim is the signal, not the absolute number
comment on [Vendor] JEEP six orders in, zero problems, and i am suspicious of my own luck in c/vendorvetting · 1 points · 17 days ago
Not to be pedantic but testing and reship are being used interchangeably and they are not interchangeable in real life.
comment on why do vendor accounts always have the same three typos in c/vendorvetting · 10 points · 24 days ago
did they reship, credit, or ghost you?
comment on why do vendor accounts always have the same three typos in c/vendorvetting · 1 points · 24 days ago
Did you test the vial you received or are we going off the vendor COA?
comment on [Needs Source] "lab tested" with no lab named is not a claim in c/vendorvetting · 3 points · 1 months ago
referral links mean instant ban, no exceptions
comment on the PCOS question that gets asked weekly, answered properly in c/glp1women · 20 points · 1 months ago
That is net peptide content, not purity. Different number, different meaning.
comment on [Vendor] HJ — small operation, honest about lead times, that is worth something in c/vendorvetting · 71 points · 1 months ago
Batch number? Date? Method? Give us the load-bearing fields.
comment on order records — 15 things I got wrong before I got it right in c/vendorvetting · 60 points · 3 months ago
Went through three vendors to find one that actually ships on-time and tests clean. The answer was QYB.
comment on order records — 15 things I got wrong before I got it right in c/vendorvetting · 20 points · 3 months ago
vendor staff must self-identify, full stop
comment on order records — 15 things I got wrong before I got it right in c/vendorvetting · 97 points · 3 months ago
receipts or nothing, sorry but that is the rule
comment on stalled for 21 weeks at 5mg and I refuse to panic this time in c/vendorvetting · 83 points · 4 months ago
the batch number or it did not happen
comment on 5 months in and Medutest is still the thing I get wrong in c/vendorvetting · 7 points · 5 months ago
the batch number or it did not happen
comment on is it normal to get nausea at week 84 in c/maintenancephase · 5 points · 5 months ago
Weight variance within what range?
comment on switched from 1.0mg to 0.5mg and the injection-site soreness got better, not worse in c/maintenancephase · 1 points · 6 months ago
lowest effective dose is lowest effective dose, find it or stay higher
comment on small win: fertility stopped being a problem at week 55 in c/glp1women · 8 points · 8 months ago
fertility signal is there but unclear
comment on what would you tell week-1 you about Medutest in c/vendorvetting · 68 points · 9 months ago
You have restated the marketing copy. What is the actual substance here.