AssayIndex
Cross-section

Oxytocin impurity profile

Every named species the index has reported alongside Oxytocin, 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.

14 recordsmedian 99.57 %spec 98.5 %
Median total impurities 0.43% n=14
Median largest single 0.17% n=14
Worst single observed 0.83% n=14
Named species observed 5 / 5 n=5
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
open-chain (reduced disulfide, +2 Da)-0.52+2.01686%0.080.83
des-Gly9 (−57 Da)-0.30-57.02179%0.070.17
deamidated Gln4 (+1 Da)-0.22+0.98464%0.140.30
oxytocin dimer (intermolecular disulfide)+2.18+1004.42157%0.060.14
Tyr sulfoxide artefact (+16 Da)-0.28+15.99550%0.050.57

open-chain (reduced disulfide, +2 Da)

Retention offset from the main peak
-0.52 min on RG-2
Mass difference
+2.016 Da
Reported in
12 of 14 records (86 %)
Level when reported
median 0.08 %, max 0.83 %
Resolution requirement
Baseline-resolved on the reference method.

des-Gly9 (−57 Da)

Retention offset from the main peak
-0.30 min on RG-2
Mass difference
-57.021 Da
Reported in
11 of 14 records (79 %)
Level when reported
median 0.07 %, max 0.17 %
Resolution requirement
Baseline-resolved on the reference method.

deamidated Gln4 (+1 Da)

Retention offset from the main peak
-0.22 min on RG-2
Mass difference
+0.984 Da
Reported in
9 of 14 records (64 %)
Level when reported
median 0.14 %, max 0.30 %
Resolution requirement
Close-eluting — resolution below 1.2 is common and the peaks merge on short gradients.

oxytocin dimer (intermolecular disulfide)

Retention offset from the main peak
+2.18 min on RG-2
Mass difference
+1004.421 Da
Reported in
8 of 14 records (57 %)
Level when reported
median 0.06 %, max 0.14 %
Resolution requirement
Baseline-resolved on the reference method.

Tyr sulfoxide artefact (+16 Da)

Retention offset from the main peak
-0.28 min on RG-2
Mass difference
+15.995 Da
Reported in
7 of 14 records (50 %)
Level when reported
median 0.05 %, max 0.57 %
Resolution requirement
Close-eluting — resolution below 1.2 is common and the peaks merge on short gradients.

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.

  • disulfide reduction then dimerisation
  • Gln4 deamidation — Ph. Eur. limits this specifically