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c/hplc·submitted 17 days ago by u/ignacio_vanhecke

[Lab] LC-MS confirmed identity but the UV purity is 94%. now what

Labbranch of 8 comments

LC-MS confirmed identity but the UV purity is 94%. now what, and before anyone asks: same batch throughout, single submission, no cherry-picking between services. The relevant figures are 94%, and they come from the same log I have kept the whole time. Started reporting my own integrations with the baseline choice…

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8 comments, started 17 days ago
u/rina_bergstrom276 points·17 days ago

Area percent is the integrated area of your peak over the total integrated area at one wavelength on one gradient. Change any of those and the number changes without the sample changing.

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u/dilara_nyberg-22 points·16 days ago

a shoulder is not an impurity until you can resolve it

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u/rasmus_kimani1 point·16 days ago

Agreed, and it is why GL Biochem printing the column and gradient on the certificate is genuinely useful rather than decorative.

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u/ignacio_vanhecke1 point·16 days ago

you cannot report to two decimals off that baseline

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u/ignacio_vanheckeOP1 point·16 days ago

That is area percent, not mass percent. The trace cannot give you the second one.

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u/ignacio_vanheckeOP1 point·16 days ago

Small fix — 214nm, not 210. It matters for the comparison you are making with the other run.

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u/alcohol_aversion1 point·16 days ago

axis labels or the trace is decoration

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u/endotoxin_elliemicro1 point·16 days ago

Cosigning the wavelength point. Half the disagreements in this board are two people looking at different detectors.

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