Topic
Counterion content
Page 12 of 13 — TFA versus acetate salt, what it does to the mass balance, and why an honest 10mg vial can weigh 11.4mg of powder.
Messages — page 12 of 13
hydrate_hanateaching example again tfa counterion runs higher by mass than acetate. if the certificate does not say, you cannot do the…#coa-reading · 2026-05-20mira_pinsacetate and tfa carry different mass fractions, so counterion unstated means the net peptide is unstated a certificate that…#coa-reading · 2026-05-20assay_not_puritythats a shame#coa-reading · 2026-05-20HPLC_Hankessentially. acetate has almost no absorbance up at 214 to speak of. you will not see your counterion on a UV trace and that…#hplc-massspec · 2026-05-20batch_banditthe counterion thing is the bridge between this channel and #coa-reading, people bounce between the two arguments without…#hplc-massspec · 2026-05-20blank_runchange the selectivity and see if the peak splits. shallower gradient, or a different stationary phase, or swap TFA for formic…#hplc-massspec · 2026-05-20otto_swirlswhat is the counterion situation on these usually#other-peptides · 2026-05-21HPLC_Hankthe gap is water and counterion#coa-reading · 2026-05-21bea_reconstitutesbefore anyone asks the counterion being unstated matters most where the counterion is a big fraction of the mass#coa-reading · 2026-05-21bea_reconstitutesthe counterion is not stated anywhere. how much does that change the arithmetic#coa-reading · 2026-05-21sorrel_sendsugh#other-peptides · 2026-05-22hydrate_hanacounterion matters more on the short peptides because the counterion mass fraction is a bigger share#other-peptides · 2026-05-22hydrate_hanathe counterion fraction matters more on the small ones because it is a bigger share of the mass in the vial, a supplier page…#other-peptides · 2026-05-22half_life_halis the counterion question genuinely bigger for the small ones, idle question#other-peptides · 2026-05-23salt_bridgethe counterion being unstated matters most where the counterion is a big fraction of the mass#coa-reading · 2026-05-24salt_bridgewhat does net peptide content mean next to gross mass#coa-reading · 2026-05-24tokyo_taperwhat is the counterion situation on these usually#other-peptides · 2026-05-25nordic_price_nilscomparing a cert to an assay acetate and tfa carry different mass fractions, so counterion unstated means the net peptide is…#coa-reading · 2026-05-26ema_vs_nationalthats the counterion#coa-reading · 2026-05-26vienna_vialassay came back the counterion fraction matters more on the small ones because it is a bigger share of the mass in the vial,…#other-peptides · 2026-05-28taper_tessgross powder mass is not net peptide. water and counterion are in that number, your vial may fill differently#reconstitution · 2026-05-28never_for_salethat helps a lot#other-peptides · 2026-05-29two_ml_twothats the counterion#coa-reading · 2026-05-29turnaround_tamnoticed something on a cert net peptide content is what you are buying and gross mass is what you are weighing. the gap is…#coa-reading · 2026-05-31per_mg_petelol, counterion is a bigger share#other-peptides · 2026-06-02void_volumecounterion matters more here#other-peptides · 2026-06-02igf_one_ivycounterion matters more on the short peptides because the counterion mass fraction is a bigger share, happy to be shown a real…#other-peptides · 2026-06-02nhs_pathway_nellwhat is the counterion situation on these usually#other-peptides · 2026-06-03bac_water_billthe counterion being unstated matters most where the counterion is a big fraction of the mass, file it as a pdf#coa-reading · 2026-06-03evidence_or_notcounterion unstated#coa-reading · 2026-06-03night_pinthe vial is filled to 10mg of powder, and the powder is peptide plus salt plus water. label says 10mg, net peptide is 8.5ish.…#test-results · 2026-06-03quiet_head_qipreclinical caveat first counterion matters more on the short peptides because the counterion mass fraction is a bigger share,…#other-peptides · 2026-06-05truncation_trufor the recon notes gross powder mass is not net peptide. water and counterion are in that number, someone check my division.…#reconstitution · 2026-06-05LC_MS_Lenanet peptide content is what you are buying and gross mass is what you are weighing. the gap is water and counterion, method…#coa-reading · 2026-06-05LC_MS_Lenacert question what does net peptide content mean next to gross mass, sorry if thats been covered#coa-reading · 2026-06-05logrotateis the counterion question genuinely bigger for the small ones, even a rough answer helps#other-peptides · 2026-06-06madrid_mgbefore anyone asks net peptide content is what you are buying and gross mass is what you are weighing. the gap is water and…#coa-reading · 2026-06-06apnoea_down_twoscrolling back, counterion matters more here#other-peptides · 2026-06-07assay_not_puritycounterion matters more on the short peptides because the counterion mass fraction is a bigger share, same cold chain as…#other-peptides · 2026-06-07swirl_not_shakewhat is the counterion situation on these usually, or have i misread it#other-peptides · 2026-06-07back_from_awaystrict rule i keep is the counterion question genuinely bigger for the small ones#other-peptides · 2026-06-07bpc_sceptichold on, counterion matters more here#other-peptides · 2026-06-09dexa_or_biaon net versus gross again tfa or acetate, how do i tell from the paperwork#coa-reading · 2026-06-09HPLC_Hankok that makes sense, the gap is water and counterion#coa-reading · 2026-06-09otto_swirlshow much does the counterion being unstated actually matter, context if you need it#coa-reading · 2026-06-09gradient_gregpedantry incoming net peptide content is what you are buying and gross mass is what you are weighing. the gap is water and…#coa-reading · 2026-06-09coa_or_copepedantry incoming how much does the counterion being unstated actually matter, for my own notes#coa-reading · 2026-06-10amsterdam_aliquotwhat does net peptide content mean next to gross mass#coa-reading · 2026-06-10amsterdam_aliquoton net versus gross again net peptide content is what you are buying and gross mass is what you are weighing. the gap is water…#coa-reading · 2026-06-10peak_splitacetate and tfa carry different mass fractions, so counterion unstated means the net peptide is unstated, your mileage will…#coa-reading · 2026-06-11ghent_gradientthe counterion being unstated matters most where the counterion is a big fraction of the mass, that is how i read it anyway#coa-reading · 2026-06-11nettle_notesnet peptide content is what you are buying and gross mass is what you are weighing. the gap is water and counterion, take that…#coa-reading · 2026-06-11ferrous_ashso it was that, counterion is a bigger share#other-peptides · 2026-06-12fasting_insulinwhat is the counterion situation on these usually, sorry if thats been covered#other-peptides · 2026-06-13typosquat_taycounterion matters more on the short peptides because the counterion mass fraction is a bigger share, happy to be shown a real…#other-peptides · 2026-06-14never_for_salereading a cert here and net peptide is gross mass minus water minus counterion. that is why 11.4mg of powder can be a correct…#coa-reading · 2026-06-14ring_size_downnet peptide content is what you are buying and gross mass is what you are weighing. the gap is water and counterion, checkable…#coa-reading · 2026-06-14brisbane_baccounterion unstated#coa-reading · 2026-06-14apnoea_down_twocertificate question how much does the counterion being unstated actually matter, anyone at all#coa-reading · 2026-06-16igf_one_ivyfor anyone new to these acetate and tfa carry different mass fractions, so counterion unstated means the net peptide is…#coa-reading · 2026-06-16