Topic
Retention time
Page 13 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 13 of 15
hair_month_fourthe retention time on this one is different from the last lot, problem#coa-reading · 2026-05-01monoisotopicbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2026-05-02rotterdam_reconthats co-elution#hplc-massspec · 2026-05-02rotterdam_reconco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-05-02vik_verifiesrelative retention time against a standard is comparable between labs. absolute minutes are not#hplc-massspec · 2026-05-02monoisotopicdo you trust an area percent from a shallow gradient#hplc-massspec · 2026-05-02deamidationretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2026-05-02fasting_insulinthats co-elution#hplc-massspec · 2026-05-02HPLC_Hankretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily if somebody says they ran a…#hplc-massspec · 2026-05-03rowan_readswhile im here baseline drift on a gradient is normal. baseline drift on an isocratic hold is your column, take that with a…#hplc-massspec · 2026-05-03marrow.modwhats a normal gradient for a peptide this size#hplc-massspec · 2026-05-03marrow.modco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-05-03nettle_notessingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2026-05-04peak_splitretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2026-05-04dublin_dosebaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2026-05-04dublin_doseco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-05-04split_the_costsingle wavelength detection can miss a co-eluting impurity that does not absorb there, i have it written down somewhere#coa-reading · 2026-05-05void_volumeretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2026-05-06void_volumesingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2026-05-06void_volumeretention time is a hint#hplc-massspec · 2026-05-06endotoxin_edbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2026-05-06careful_claimshow do you tell co-elution from a clean single peak#hplc-massspec · 2026-05-06ferrous_ashretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily, thats one data point#hplc-massspec · 2026-05-06LC_MS_Lenaco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-05-07LC_MS_Lenaretention time is a hint#hplc-massspec · 2026-05-07LC_MS_Lenashallow gradient#hplc-massspec · 2026-05-07peak_splitshallow gradient#hplc-massspec · 2026-05-08peak_splitdo you trust an area percent from a shallow gradient#hplc-massspec · 2026-05-08first_month_fithe retention time on this one is different from the last lot, problem#coa-reading · 2026-05-09group_buy_gwensingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2026-05-09shame_and_medsdoes retention time on its own tell you what the compound is#hplc-massspec · 2026-05-09shame_and_medswhats a normal gradient for a peptide this size#hplc-massspec · 2026-05-09coelution_caibaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2026-05-09quiet_head_qiretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2026-05-10brisbane_bacretention time is a hint#hplc-massspec · 2026-05-10brisbane_bacshallow gradient#hplc-massspec · 2026-05-10area_percentretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily, not advice obviously#hplc-massspec · 2026-05-10forty_five_kgthats co-elution#hplc-massspec · 2026-05-10tail_factorco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-05-10two_labs_two_answershow do you tell co-elution from a clean single peak#hplc-massspec · 2026-05-10two_labs_two_answerswhats a normal gradient for a peptide this size#hplc-massspec · 2026-05-10ms_ms_miraco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2026-05-11hot_mailboxdoes retention time on its own tell you what the compound is#hplc-massspec · 2026-05-11HPLC_Hankbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2026-05-11amylin_amyhow do you tell co-elution from a clean single peak#hplc-massspec · 2026-05-11monoisotopicbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2026-05-12two_four_ceilinggenuine question does retention time on its own tell you what the compound is#hplc-massspec · 2026-05-12gip_glp_gilthats co-elution#hplc-massspec · 2026-05-12HPLC_Hankretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2026-05-13HPLC_Hankretention time is a hint#hplc-massspec · 2026-05-13HPLC_Hankwhats a normal gradient for a peptide this size#hplc-massspec · 2026-05-13appetite_backthats co-elution#hplc-massspec · 2026-05-13HPLC_Hankdoes retention time on its own tell you what the compound is#hplc-massspec · 2026-05-13gorse_gainsthe retention time on this one is different from the last lot, problem#coa-reading · 2026-05-14marrow.modretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2026-05-14deamidationrelative retention time against a standard is comparable between labs. absolute minutes are not#hplc-massspec · 2026-05-14turnaround_tamdo you trust an area percent from a shallow gradient#hplc-massspec · 2026-05-14deamidationretention time is a hint#hplc-massspec · 2026-05-14deamidationthats co-elution#hplc-massspec · 2026-05-14HPLC_Hanksingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2026-05-15