GLPHubglpresearchhub.com
Read-only archive. GLP Research Hub is a static community record — nothing here is for sale, no account is needed, and no vote you cast is counted. Why?
Single comment threadYou are looking at one branch of [Lab] HJ cagri — Janoshik came back 97.5% against a claimed 97.0% — 53 comments in the full submission. View in context.
6.1k
c/hplc·submitted 11 months ago by u/ignacio_vanhecke

[Lab] HJ cagri — Janoshik came back 97.5% against a claimed 97.0%

Labbranch of 7 comments

HJ cagri — Janoshik came back 97.5% against a claimed 97.0%, and before anyone asks: same batch throughout, single submission, no cherry-picking between services. The numbers the title promised, since a headline without them is worthless: 97.5% and 97.0%. Everything below is context for those. Sent the same vial to…

Read the full submission and all 53 comments →

This branch

7 comments, started 11 months ago
u/ewan_marchand662 points·11 months ago

Mass spectrometry answers identity. UV purity answers relative quantity under the run conditions. A document with one and not the other is answering half the question, and the half it answers should be stated.

replysharereportpermalink
u/honest_syringe_pls372 points·11 months ago

Did you run a blank between injections?

replysharereportpermalink
u/runa_cabrera253 points·11 months ago

That is area percent, not mass percent. The trace cannot give you the second one.

replysharereportpermalink
u/ignacio_vanheckeOP447 points·11 months ago·edited

Chased a ghost peak for three weeks. It was the plumbing. It is always the plumbing.

replysharereportpermalink
u/ignacio_vanheckeOP281 points·11 months ago·edited

HJ sent me the column, the gradient and the theoretical mass without being asked. That is a short list and they are on it.

replysharereportpermalink
[deleted]186 points·11 months ago

[deleted]

replysharereportpermalink
u/runa_cabrera91 points·11 months ago

report the method or do not report the number

replysharereportpermalink

← back to the whole thread

About c/hplc

The analytical deep end: RP-HPLC methods, gradient design, integration decisions, LC-MS confirmation, amino-acid analysis, water content, and why two labs can report 98.1% and 96.4% on the same vial and both be right. Post the chromatogram, not the summary line.

32kmembers
130submissions
Sep 2023created
submissions / month, last year
Sponsored

PeptideMeter Analytics

Independent testing plus vendor-level trend data. Community-funded, unaffiliated.

peptidemeter.com
More in c/hplc
c/hplc rules
  1. Chromatogram or it did not happen. Axis labels included.
  2. State the method: column, gradient, detection wavelength, injection volume.
  3. Area% is not mass%. Posts that conflate them get a correction flair, not a removal.
  4. Independent community. Nobody here sells anything, and anyone who tries is banned.
  5. Not medical advice. Describe what you did; never prescribe to a stranger.
  6. Claims need evidence. Batch numbers, dated screenshots, independent test reports, or a citation.
  7. No referral links, discount codes or affiliate URLs. Permanent ban, no appeal.
  8. No contact handles, wallet addresses or tracking numbers — they identify people.
  9. Be recognisably decent. Disagree hard, insult nobody.
Full rules and how they are enforced →
Moderators
u/sig_figs_samu/hplc_hobbyistu/peak_area_peteu/mass_spec_maggie
Volunteers. Unpaid, unaffiliated, and reachable through modmail only.
Before you read on

Several compounds discussed on GLP Research Hub are sold for research use only and are not approved for human use anywhere. Nothing here is medical advice and none of it is written by your clinician. If a post reads like an instruction, treat it as a description of what one stranger did.

Full disclaimer →