#hplc-massspec 2024-05-25

Saturday9 messages2 participantstimes are UTC

Highlights from this day

retention_time — semaglutide is about 4113.6 Da. [M+2H]2+ lands near 2057.8, [M+3H]3+ near 1372.2 18:30
retention_time — a certificate with a number and no chromatogram is asking you to trust the integration you cannot see 18:31
retention_time — baseline drift on a gradient is normal. baseline drift on an isocratic hold is your column 18:37
retention_time — relative retention time against a standard is comparable between labs. absolute minutes are not 18:38

retention_time 18:30

semaglutide is about 4113.6 Da. [M+2H]2+ lands near 2057.8, [M+3H]3+ near 1372.2

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a certificate with a number and no chromatogram is asking you to trust the integration you cannot see

does ms/ms actually prove identity or just make it very likely

LC_MS_Lenalab18:34

do the arithmetic

retention_time 18:37

baseline drift on a gradient is normal. baseline drift on an isocratic hold is your column

relative retention time against a standard is comparable between labs. absolute minutes are not

weights-monthly.csv

585 rows · not retained in the public archive

sorry to jump in tirzepatide is about 4813.5 Da, so 2+ is near 2407.8 and 3+ near 1605.5

thats the solvent peak

peak   RRT    area%    note
  1   0.42     0.31    solvent front
  2   0.88     0.44    related substance
  3   1.00    98.72    main
  4   1.14     0.53    related substance

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oxidation is about plus 15.99 Da and is usually methionine or tryptophan