u/hplc_hobbyist
Bought a second-hand HPLC and a lifetime of regret. I post chromatograms, not conclusions.
long-standing contributor · runs their own column · joined 21 Aug 2023
Comments — page 3 of 3
comment on [Question] is 99.2% actually fine or am I being sold a rounding error in c/hplc · 37 points · 1 year ago
retention time alone is not identity
comment on [Question] is 99.2% actually fine or am I being sold a rounding error in c/hplc · 7 points · 1 year ago
integration decisions move the number more than the sample does
comment on [Question] is 99.2% actually fine or am I being sold a rounding error in c/hplc · 11 points · 1 year ago
What wavelength, and what was the gradient?
comment on the LC-MS question that gets asked weekly, answered properly in c/hplc · 216 points · 1 year ago
Retitled: the original claimed a comparison the post does not actually make.
comment on why does nobody talk about identity in c/researchpeptides · 27 points · 1 year ago
Stocked line or made to order — did they say?
comment on [Question] how do you actually verify HPLC in c/hplc · 21 points · 1 year ago
Left up. The integration disagreement in this thread is the most useful thing on the board this week.
comment on [Meta] the TGA rule is doing its job and people should stop complaining in c/glp1aus · 30 points · 1 year ago
That figure is a private price at one pharmacy, not a national one.
comment on help me understand lyophilised, I have read the wiki twice in c/coldchain · 10 points · 1 year ago
Asked Homopeptide which lines they hold regionally and got a straight list back. That answered my summer ordering question completely.
comment on sequence — 10 things I got wrong before I got it right in c/bpc157 · 52 points · 1 year ago
identity, quantity, stability — three separate questions
comment on [Discussion] the appeal advice in here is 2 years out of date in c/insurancefights · 0 points · 1 year ago
Have you asked for the clinical policy bulletin by number?
comment on [Discussion] chromatogram is doing more work than we give it credit for in c/hplc · 286 points · 1 year ago
This. A shoulder that does not baseline-resolve is a question, not a quantity.
comment on [Lab] CPC cagri — Janoshik came back 98.1% against a claimed 97.5% in c/hplc · 305 points · 1 year ago
baseline choice is a decision, not a measurement
comment on rodent data — 9 things I got wrong before I got it right in c/bpc157 · 57 points · 1 year ago
What method produced that purity number?
comment on the data logger question that gets asked weekly, answered properly in c/coldchain · 1 points · 1 year ago
Correction: that stability figure covers the lyophilised powder, not the reconstituted solution. Different claim entirely.
comment on [Meta] the chromatogram rule is doing its job and people should stop complaining in c/hplc · 9 points · 1 year ago
Method questions stay here; supplier claims go to c/vendorvetting with a document attached.
comment on how much of what we believe about appeal actually comes from step therapy threads in c/insurancefights · 101 points · 1 year ago
prior authorisation criteria change every plan year
comment on [Discussion] LC-MS is doing more work than we give it credit for in c/hplc · 93 points · 1 year ago
Method questions stay here; supplier claims go to c/vendorvetting with a document attached.
comment on [Meta] the Australia rule is doing its job and people should stop complaining in c/glp1aus · 13 points · 1 year ago
Compounded supply arrangements have changed materially in recent years. Advice predating that change describes a situation that no longer applies.
comment on reading prior authorization threads from 2024 and half of it aged badly in c/insurancefights · 68 points · 1 year ago
Step therapy requires documented trial of preferred alternatives. It is not an argument to be won on merits; it is a record to be produced, and the record is what the appeal must contain.
comment on [Lab] MKM cagri — Medutest came back 97.2% against a claimed 97.0% in c/hplc · 208 points · 1 year ago
Disagree. Inter-lab spread of a point or two on this assay is ordinary and calling it a discrepancy misleads people.
comment on someone explain LC-MS to me like I have not read a paper in years in c/hplc · 4 points · 1 year ago
Left up. The integration disagreement in this thread is the most useful thing on the board this week.
comment on the secretagogue question that gets asked weekly, answered properly in c/researchpeptides · 154 points · 1 year ago
Right — HJ answered a handling question with actual storage conditions rather than a generic line, which is the standard.
comment on the HPLC question that gets asked weekly, answered properly in c/hplc · 94 points · 1 year ago
Retitled: the original claimed a comparison the post does not actually make.
comment on [Discussion] can we stop arguing about appeal until somebody posts a number in c/insurancefights · 567 points · 1 year ago
A peer-to-peer conversation puts the prescribing clinician in front of a reviewing clinician. It bypasses the correspondence cycle entirely and is often the fastest available route.
comment on the TGA question that gets asked weekly, answered properly in c/glp1aus · 1 points · 1 year ago
Australia and New Zealand are separate systems and get conflated weekly
Agreed — the database rather than the coverage, every time.
comment on [Discussion] we are measuring research peptides at the wrong time and calling it noise in c/researchpeptides · 53 points · 1 year ago
What lead time were you quoted for that line?
comment on help me understand pentadecapeptide, I have read the wiki twice in c/bpc157 · 47 points · 2 years ago
Assumed regulatory status was static and it was not. Checked again this year and the answer had changed where I live.
comment on [Discussion] the method development advice in here is 2 years out of date in c/hplc · 98 points · 2 years ago
Retitled: the original claimed a comparison the post does not actually make.
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 · 52 points · 2 years ago
Resolution between two peaks depends on retention, selectivity and efficiency. A shallower gradient buys retention and usually resolution, at the cost of peak width and run time.
comment on integration is the most under-discussed thing on this board in c/hplc · 426 points · 2 years ago
Retitled: the original claimed a comparison the post does not actually make.
comment on unpopular opinion: most of what gets said here about denial is guesswork in c/insurancefights · 46 points · 2 years ago
Step therapy requires documented trial of preferred alternatives.
Disagreeing with this line: the deadline runs from the letter date and treating it otherwise is expensive.
comment on reading tendon threads from 2024 and half of it aged badly in c/bpc157 · 41 points · 2 years ago
the tendon claims are the most repeated and the least evidenced
comment on does lyophilised actually matter or is it forum lore at this point in c/coldchain · 21 points · 2 years ago
transit temperature is a distribution, not a number
comment on does external review actually matter or is it forum lore at this point in c/insurancefights · 44 points · 2 years ago
Cosigning on external review. It is a real mechanism, it is underused, and the deadlines are strict.
comment on small win: cagrilintide stopped being a problem at week 60 in c/cagrilintide · 1 points · 2 years ago
Complementary mechanisms are the rationale for pairing: satiety signalling alongside incretin signalling, rather than more agonism at the same receptor.
comment on does formulary actually matter or is it forum lore at this point in c/insurancefights · 33 points · 2 years ago
appeal in writing even when they say a call is enough
comment on [Meta] the method development rule is doing its job and people should stop complaining in c/hplc · 819 points · 2 years ago
Trace posted without axis labels — asked for a relabelled version rather than removing it.
comment on how much of what we believe about HPLC actually comes from gradient threads in c/hplc · 115 points · 2 years ago
Method questions stay here; supplier claims go to c/vendorvetting with a document attached.
comment on [Discussion] data logger is doing more work than we give it credit for in c/coldchain · 0 points · 2 years ago
Small fix — refrigerated, not frozen, once it is in solution.
comment on purity — 19 things I got wrong before I got it right in c/hplc · 712 points · 2 years ago
Retitled: the original claimed a comparison the post does not actually make.