The reported figure derives from the plate count and the retention gap, via the pharmacopoeial form with the sum of both peak widths in the denominator. It is a calculated quantity, not a measured one, and it inherits the plate count's uncertainty.
valley_drop
Integration geometry. Valley-to-valley on unresolved shoulders, drop-line on resolved ones.
Section 1
Contribution
Comments technically on records submitted by others. Annotations are signed and are not moderated for agreement.
Records submitted
0
n=0
Annotations
261
n=261
Median purity submitted
suppressed
n=0
n<3 — see individual records
Suppliers covered
0
n=0
This handle has submitted no records. Annotators comment on other people's submissions and are not required to submit.
Section 2
Annotations
Signed technical comments on records. The index does not moderate annotations for agreement with its own arithmetic, and several of these disagree with it. Where a handle has made the same point on several records, one instance is shown and the rest are reachable from the records themselves.
Valley height relative to the smaller peak is the practical criterion an operator uses, and it is not on the report. Resolution is a proxy for it and an imperfect one on asymmetric pairs.
Integration on this trace is unambiguous: C18 diacid regioisomer at 1.77 % is baseline-resolved from the main peak, so 96.32 % is a measurement rather than a boundary decision.
Nothing on this record is flagged for resolution and nothing will be. The figure exists so the reader can weight the purity number, which is its only purpose.
native GRF (1-29) (−59 Da) at 1.07 % elutes close enough to the main peak that drop-line and valley-to-valley will not agree. The index prints the resolution figure and applies no criterion to it — how close the nearest impurity sits is a property of the compound and the gradient, not of the system. What matters is that the convention used is stated.
[D-Aib8]-diastereomer at 0.10 % elutes close enough to the main peak that drop-line and valley-to-valley will not agree. The index prints the resolution figure and applies no criterion to it — how close the nearest impurity sits is a property of the compound and the gradient, not of the system. What matters is that the convention used is stated.
C-terminal free acid (+1 Da) at 0.07 % elutes close enough to the main peak that drop-line and valley-to-valley will not agree. The index prints the resolution figure and applies no criterion to it — how close the nearest impurity sits is a property of the compound and the gradient, not of the system. What matters is that the convention used is stated.
Purity at 99.66 % and water at 4.42 %: the two numbers are independent and both are needed. Excellent chromatography on a wet cake still yields less peptide per vial than the label implies.
The index's position is that the integration convention must be stated, not that any particular convention must be used. Both are defensible; only one can be reported and it should be named.
des-Lys (−128 Da) at 0.09 % elutes close enough to the main peak that drop-line and valley-to-valley will not agree. The index prints the resolution figure and applies no criterion to it — how close the nearest impurity sits is a property of the compound and the gradient, not of the system. What matters is that the convention used is stated.
Largest single impurity is C-terminal free acid (+1 Da) at 0.12 % area, and it is the only named peak above 0.1 %. The integration is unambiguous and 99.71 % can be taken at face value.
hydrolysed maleimide (+18 Da) at 0.90 % elutes close enough to the main peak that drop-line and valley-to-valley will not agree. The index prints the resolution figure and applies no criterion to it — how close the nearest impurity sits is a property of the compound and the gradient, not of the system. What matters is that the convention used is stated.
Showing 12 distinct comments of 261 annotations by this handle.