If the nearest impurity carries an aromatic residue the parent lacks, dual-wavelength detection separates them without any chromatographic change at all. Cheap and underused.
lambda_280
Aromatic-selective detection for oxidation-product assignment.
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
56
n=56
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.
Aromatic-selective detection at 280 nm would identify whether des-AEEA semaglutide (−145 Da) carries the chromophore. That distinguishes a truncation from a modification in about ten minutes of instrument time.
Aromatic-selective detection at 280 nm would identify whether des-Gln truncate (−128 Da) carries the chromophore. That distinguishes a truncation from a modification in about ten minutes of instrument time.
Aromatic-selective detection at 280 nm would identify whether oxidised Trp (+16 Da) carries the chromophore. That distinguishes a truncation from a modification in about ten minutes of instrument time.
98.18 % on L-Glutathione (reduced) is below the index specification for the class. The interesting part is the distribution: γ-Glu-Cys (−57 Da) at 0.95 % is doing most of the work, and that species is a synthesis artefact rather than a degradation product. This is a process observation about lot WXT-2512-P2820, not a storage one.
Aromatic-selective detection at 280 nm would identify whether [D-Trp]-epimer carries the chromophore. That distinguishes a truncation from a modification in about ten minutes of instrument time.
97.98 % on MOTS-c is below the index specification for the class. The interesting part is the distribution: Met1 sulfoxide (+16 Da) at 0.89 % is doing most of the work, and that species is a synthesis artefact rather than a degradation product. This is a process observation about lot WXT-2512-K3109, not a storage one.
Aromatic-selective detection at 280 nm would identify whether N-acetyl semax free acid (+1 Da) carries the chromophore. That distinguishes a truncation from a modification in about ten minutes of instrument time.
98.49 % on Gonadorelin is below the index specification for the class. The interesting part is the distribution: oxidised Trp (+16 Da) at 0.76 % is doing most of the work, and that species is a synthesis artefact rather than a degradation product. This is a process observation about lot BCH-2510-F4167, not a storage one.
The record is published in full, including the impurity table that explains it. A number below specification with a named impurity profile beside it is more useful than a number above specification with nothing beside it.
Aromatic-selective detection at 280 nm would identify whether diketopiperazine (−18 Da) carries the chromophore. That distinguishes a truncation from a modification in about ten minutes of instrument time.
Aromatic-selective detection at 280 nm would identify whether aspartimide (−18 Da) carries the chromophore. That distinguishes a truncation from a modification in about ten minutes of instrument time.
Showing 12 distinct comments of 56 annotations by this handle.