Liquid chromatography coupled to mass spectrometry: separation and identification in one run, and the method of choice when you need to know not just how much impurity there is but what it is.
Details up front: KP · retatrutide. I can parse the result. I am less sure what it licenses me to conclude. I have deliberately not looked at anyone else’s…
For reference: QYB · Hunan Aslsen Technology. I am trying to choose between two options that are usually discussed as though only one exists. I am not optimising for…
What I have: 96.4% · Janoshik · 98.8%. Before I write this off, I want to check whether it is a known failure mode. I have the lot number, the certificate and the…
I have been quoted roughly four times the price of a purity-plus-identity panel for something described as "tryptic digest with LC-MS/MS peptide mapping and sequence…
The recurring point in this tag is that stereoisomers and sequence isomers are invisible to mass spectrometry. I accept that for intact mass. What I want to know is…
Conditions: 97.6% · tirzepatide. Please show the division. I want to check my own against yours. I would like the general form as well as the specific number, so I…
What I am working with: dulaglutide · sampling plan. I have read the primary source rather than the summary, which has left me with more questions. I understand the…
Vendor listings say "sterile" and "sterile filtered" more or less interchangeably, and I have started to suspect these words are doing no work at all. I would like to…
Numbers first: SWB · a quantified content assay. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the…
Conditions: HJ · Guangzhou JEEP Biotechnology. I would like the axes of comparison first and the recommendation second. I have tried the first option and it works;…
The deconvolved mass spectrum on a tirzepatide report shows the expected 4813.5 peak plus three satellites I do not understand: one at 4795.5, one at 4814.5 that…
I have two third-party reports in front of me. Both say "identity confirmed by ESI-MS" and both include a spectrum, but the spectra look nothing like the single clean…
I received a mapping report on tirzepatide. It states "sequence coverage: 100%" in bold at the top, and then the fragment table has exactly two entries in it.…
Conditions: a quantified content assay · tirzepatide. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in view and I…
HPLC purity, identity confirmation and quantified content on the vial you actually hold. Reports arrive with the chromatogram attached, not just a number.
Submit a sampleFounded 1998. ISO 9001 and cGMP certified, 1,500+ staff and 200+ patents. The synthesis house behind a great many of the vials that get sent out for testing - batch-specific documentation with every order.
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