AssayIndex
Cross-section

Liraglutide impurity profile

Every named species the index has reported alongside Liraglutide, 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.

88 recordsmedian 99.00 %spec 97.5 %
Median total impurities 1.00% n=88
Median largest single 0.52% n=88
Worst single observed 2.04% n=88
Named species observed 6 / 6 n=6
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
des-palmitoyl liraglutide (−238 Da)-3.44-238.23095%0.201.56
γ-Glu regioisomer+0.41mass-identical92%0.061.20
deamidated (Asn→Asp, +1 Da)-0.48+0.98483%0.141.44
palmitoyl bis-adduct (+238 Da)+2.88+238.23082%0.092.04
des-His1 truncate (−137 Da)-1.02-137.05980%0.070.92
liraglutide dimer+3.15+3748.96372%0.050.79

des-palmitoyl liraglutide (−238 Da)

Retention offset from the main peak
-3.44 min on RG-2
Mass difference
-238.230 Da
Reported in
84 of 88 records (95 %)
Level when reported
median 0.20 %, max 1.56 %
How it separates
Baseline-resolved on the reference method.

γ-Glu regioisomer

Retention offset from the main peak
+0.41 min on RG-2
Mass difference
mass-identical — chromatography only
Reported in
81 of 88 records (92 %)
Level when reported
median 0.06 %, max 1.20 %
How it separates
Chromatography only. A gradient long enough to separate it; no mass spectrometer of any resolution will.

deamidated (Asn→Asp, +1 Da)

Retention offset from the main peak
-0.48 min on RG-2
Mass difference
+0.984 Da
Reported in
73 of 88 records (83 %)
Level when reported
median 0.14 %, max 1.44 %
How it separates
Baseline-resolved on the reference method.

palmitoyl bis-adduct (+238 Da)

Retention offset from the main peak
+2.88 min on RG-2
Mass difference
+238.230 Da
Reported in
72 of 88 records (82 %)
Level when reported
median 0.09 %, max 2.04 %
How it separates
Baseline-resolved on the reference method.

des-His1 truncate (−137 Da)

Retention offset from the main peak
-1.02 min on RG-2
Mass difference
-137.059 Da
Reported in
70 of 88 records (80 %)
Level when reported
median 0.07 %, max 0.92 %
How it separates
Baseline-resolved on the reference method.

liraglutide dimer

Retention offset from the main peak
+3.15 min on RG-2
Mass difference
+3748.963 Da
Reported in
63 of 88 records (72 %)
Level when reported
median 0.05 %, max 0.79 %
How it separates
Baseline-resolved on the reference method.

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.

  • palmitoyl amide hydrolysis under alkaline conditions
  • fibrillation at the isoelectric point (pH ≈ 4.6) — avoid acidic reconstitution