AssayIndex
Cross-section

Glucagon impurity profile

Every named species the index has reported alongside Glucagon, how often, at what level, and what its presence implies about the synthesis or the handling. Reporting threshold is 0.05 % area; anything below it is invisible to this page and is silently added to the main peak.

15 recordsmedian 99.20 %spec 98.0 %
Median total impurities 0.80% n=15
Median largest single 0.48% n=15
Worst single observed 0.83% n=15
Named species observed 4 / 4 n=4
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
Met27 sulfoxide (+16 Da)-0.79+15.995100%0.340.79
deamidated Asn28 (+1 Da)-0.36+0.984100%0.170.83
des-His1 (−137 Da)-0.94-137.059100%0.140.23
glucagon fibril-derived aggregate+2.61mass-identical100%0.110.76

Met27 sulfoxide (+16 Da)

Retention offset from the main peak
-0.79 min on RG-2
Mass difference
+15.995 Da
Reported in
15 of 15 records (100 %)
Level when reported
median 0.34 %, max 0.79 %
How it separates
Baseline-resolved on the reference method.

deamidated Asn28 (+1 Da)

Retention offset from the main peak
-0.36 min on RG-2
Mass difference
+0.984 Da
Reported in
15 of 15 records (100 %)
Level when reported
median 0.17 %, max 0.83 %
How it separates
Baseline-resolved on the reference method.

des-His1 (−137 Da)

Retention offset from the main peak
-0.94 min on RG-2
Mass difference
-137.059 Da
Reported in
15 of 15 records (100 %)
Level when reported
median 0.14 %, max 0.23 %
How it separates
Baseline-resolved on the reference method.

glucagon fibril-derived aggregate

Retention offset from the main peak
+2.61 min on RG-2
Mass difference
mass-identical — chromatography only
Reported in
15 of 15 records (100 %)
Level when reported
median 0.11 %, max 0.76 %
How it separates
Chromatography only. A gradient long enough to separate it; no mass spectrometer of any resolution will.

Degradation pathways

Degradants are a handling finding rather than a synthesis finding. A lot that shipped clean and arrived oxidised tells you about the courier, not the chemist.

  • fibrillation within hours at acidic pH and room temperature — the classic instability
  • Met27 oxidation
  • Asn28 deamidation