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HP

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

9,621post karma
11,536comment karma
8submissions
122comments

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

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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

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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?

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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.

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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?

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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.

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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.

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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.

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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

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comment on [Discussion] the appeal advice in here is 2 years out of date in c/insurancefights · 0 points · 1 year ago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?

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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.

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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

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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?

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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.

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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.

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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

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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?

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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.

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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.

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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.

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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.

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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.

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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

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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

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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.

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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.

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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

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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.

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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.

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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.

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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.

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