Topic
Retention time
Page 15 of 15 — Why retention time is a hint and not a fingerprint, and what co-elution can hide behind a beautiful single peak.
Messages — page 15 of 15
abdo_two_inchretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2026-06-08cold_pack_carlasorry to jump in how do you tell co-elution from a clean single peak#hplc-massspec · 2026-06-08flint_fillsthe retention time on this one is different from the last lot, problem#coa-reading · 2026-06-09lisbon_lotsingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2026-06-09tga_noticesingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2026-06-10ten_of_tenretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2026-06-10nettle_notesretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2026-06-11per_mg_peteretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2026-06-12ms_ms_miradoes retention time on its own tell you what the compound is co-elution is the failure mode that a beautiful single peak is…#hplc-massspec · 2026-06-13ms_ms_mirathats co-elution#hplc-massspec · 2026-06-13site_itchretention time is a hint#hplc-massspec · 2026-06-13peak_splitrelative retention time against a standard is comparable between labs. absolute minutes are not#hplc-massspec · 2026-06-14peak_splitwhile im here do you trust an area percent from a shallow gradient#hplc-massspec · 2026-06-14area_percentthats co-elution#hplc-massspec · 2026-06-14abdo_two_inchthe retention time on this one is different from the last lot, problem#coa-reading · 2026-06-16cold_chain_cmdrretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2026-06-16mira_pinsco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-06-16mira_pinsretention time is a hint#hplc-massspec · 2026-06-16orfor_watchquick one do you trust an area percent from a shallow gradient#hplc-massspec · 2026-06-17olive_ordersthats co-elution#hplc-massspec · 2026-06-17olive_ordersco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-06-17factory_direct_fishallow gradient#hplc-massspec · 2026-06-17logrotateretention time shifts between runs are normal. relative retention time is the number to compare, not advice obviously i asked…#coa-reading · 2026-06-18ms_ms_miraretention time is a hint#hplc-massspec · 2026-06-18monoisotopicdo you trust an area percent from a shallow gradient if the number you are staring at is a third of what you expected, do the…#hplc-massspec · 2026-06-18coa_or_coperelative retention time against a standard is comparable between labs. absolute minutes are not#hplc-massspec · 2026-06-18coa_or_copecoming back to this co-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-06-18border_force_bexco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-06-19drawup_deerelative retention time against a standard is comparable between labs. absolute minutes are not, i have it written down…#hplc-massspec · 2026-06-19chaser_chrissingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2026-06-20related_substhats co-elution#hplc-massspec · 2026-06-20snac_and_waterdoes retention time on its own tell you what the compound is#hplc-massspec · 2026-06-20snac_and_waterbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2026-06-20tokyo_taperretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2026-06-21bea_reconstitutesthe retention time on this one is different from the last lot, problem#coa-reading · 2026-06-21bea_reconstitutessingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2026-06-21cat_on_the_trayretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily a dimer usually shows up…#hplc-massspec · 2026-06-23taper_tesssingle wavelength detection can miss a co-eluting impurity that does not absorb there, i think#coa-reading · 2026-06-24area_percentretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2026-06-24blank_runrelative retention time against a standard is comparable between labs. absolute minutes are not#hplc-massspec · 2026-06-26blank_runthats co-elution#hplc-massspec · 2026-06-26acetate_ashwhats a normal gradient for a peptide this size#hplc-massspec · 2026-06-26acetate_ashdo you trust an area percent from a shallow gradient#hplc-massspec · 2026-06-26half_life_halbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2026-06-26ghent_gradientco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-06-26assay_not_purityshallow gradient#hplc-massspec · 2026-06-26assay_not_purityretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2026-06-26charge_stateunrelated but retention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily monoisotopic…#hplc-massspec · 2026-06-27glucagon_armco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-06-27no_chargebackretention time is a hint#hplc-massspec · 2026-06-27shame_and_medsrelative retention time against a standard is comparable between labs. absolute minutes are not#hplc-massspec · 2026-06-27shame_and_medsbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2026-06-27no_chargebackshallow gradient#hplc-massspec · 2026-06-27ms_ms_mirahow do you tell co-elution from a clean single peak#hplc-massspec · 2026-06-27fasting_insulindoes retention time on its own tell you what the compound is#hplc-massspec · 2026-06-28fasting_insulinretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2026-06-28otto_swirlsretention time is a hint#hplc-massspec · 2026-06-28fasting_insulinwhile im here how do you tell co-elution from a clean single peak#hplc-massspec · 2026-06-28fasting_insulinshallow gradient#hplc-massspec · 2026-06-28logrotateretention time is a hint#hplc-massspec · 2026-06-30