Topic
Retention time
Page 5 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 5 of 15
void_volumeco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2025-07-28evidence_or_notsingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2025-07-29peak_splitretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2025-07-29impersonator_ipretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2025-07-31area_percentretention time is a hint#hplc-massspec · 2025-07-31fibre_firstbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2025-08-02void_volumehow do you tell co-elution from a clean single peak#hplc-massspec · 2025-08-02void_volumerelative retention time against a standard is comparable between labs. absolute minutes are not, n of 1 obviously#hplc-massspec · 2025-08-02void_volumeshallow gradient#hplc-massspec · 2025-08-02vienna_vialdo you trust an area percent from a shallow gradient#hplc-massspec · 2025-08-02nausea_windowthe retention time on this one is different from the last lot, problem#coa-reading · 2025-08-05pinch_not_stretchupdate on the earlier thing retention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2025-08-06van_isle_vialdoes retention time on its own tell you what the compound is#hplc-massspec · 2025-08-07van_isle_vialok so how do you tell co-elution from a clean single peak#hplc-massspec · 2025-08-07HPLC_Hankretention time is a hint#hplc-massspec · 2025-08-15salt_bridgesingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2025-08-16salt_bridgethe retention time on this one is different from the last lot, problem#coa-reading · 2025-08-17coa_or_copesingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2025-08-17monoisotopicbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column, take that with a pinch of salt#hplc-massspec · 2025-08-17two_ml_tworetention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2025-08-17lot_number_louretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2025-08-21dose_down_dararetention time is a hint#hplc-massspec · 2025-08-21border_force_bexdo 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 · 2025-08-21cat_on_the_trayslightly off topic but single wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2025-08-23cat_on_the_traythe retention time on this one is different from the last lot, problem#coa-reading · 2025-08-23gus_chartsshallow gradient#hplc-massspec · 2025-08-23gus_chartsbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2025-08-23ms_ms_mirathats co-elution#hplc-massspec · 2025-08-23a1c_lagretention time is a hint#hplc-massspec · 2025-08-23a1c_lagretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2025-08-23turnaround_tamretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2025-08-24adelaide_assayretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2025-08-26adelaide_assayshallow gradient#hplc-massspec · 2025-08-26mhra_unlicensedhow do you tell co-elution from a clean single peak#hplc-massspec · 2025-08-27logrotateco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2025-08-27mhra_unlicensedunrelated but baseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2025-08-27rotate_the_sitethe retention time on this one is different from the last lot, problem#coa-reading · 2025-08-30endotoxin_edrelative retention time against a standard is comparable between labs. absolute minutes are not#hplc-massspec · 2025-09-01identity_shiftthats co-elution#hplc-massspec · 2025-09-02void_volumethe retention time on this one is different from the last lot, problem#coa-reading · 2025-09-05evidence_or_notsingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2025-09-05fridge_thermoretention time is a hint#hplc-massspec · 2025-09-06non_scale_winbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column if the lab reports area percent…#hplc-massspec · 2025-09-06non_scale_winwhats a normal gradient for a peptide this size#hplc-massspec · 2025-09-06HPLC_Hankretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2025-09-06mag_citraterelative retention time against a standard is comparable between labs. absolute minutes are not#hplc-massspec · 2025-09-07alcohol_hitssingle wavelength detection can miss a co-eluting impurity that does not absorb there#coa-reading · 2025-09-09fasting_insulinthats co-elution#hplc-massspec · 2025-09-09fasting_insulinrelative retention time against a standard is comparable between labs. absolute minutes are not#hplc-massspec · 2025-09-09fake_trackingbaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column#hplc-massspec · 2025-09-09pbs_pipretention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily#hplc-massspec · 2025-09-09seven_five_sweetretention time is a hint#hplc-massspec · 2025-09-09ms_ms_miraretention time shifts between runs are normal. relative retention time is the number to compare#coa-reading · 2025-09-12vik_verifiesthe retention time on this one is different from the last lot, problem#coa-reading · 2025-09-14appetite_backdo you trust an area percent from a shallow gradient#hplc-massspec · 2025-09-14area_percentrelative retention time against a standard is comparable between labs. absolute minutes are not#hplc-massspec · 2025-09-14appetite_backthats co-elution#hplc-massspec · 2025-09-14ruo_onlyco-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2025-09-14ruo_onlybaseline drift on a gradient is normal. baseline drift on an isocratic hold is your column a dimer usually shows up late and…#hplc-massspec · 2025-09-14relabel_watchok so co-elution is the failure mode that a beautiful single peak is most likely to be hiding#hplc-massspec · 2025-09-16