AssayIndex
Cross-section

Desmopressin impurity profile

Every named species the index has reported alongside Desmopressin, 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.

33 recordsmedian 99.46 %spec 98.5 %
Median total impurities 0.54% n=33
Median largest single 0.31% n=33
Worst single observed 1.06% n=33
Named species observed 4 / 4 n=4
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
[L-Arg8]-diastereomer (vasopressin-like)-0.18mass-identical97%0.080.36
open-chain (reduced disulfide, +2 Da)-0.54+2.01691%0.101.06
desmopressin dimer+2.24+1066.41185%0.120.43
des-amino artefact (+16 Da)-0.30+15.99582%0.081.01

[L-Arg8]-diastereomer (vasopressin-like)

Retention offset from the main peak
-0.18 min on RG-2
Mass difference
mass-identical — chromatography only
Reported in
32 of 33 records (97 %)
Level when reported
median 0.08 %, max 0.36 %
Resolution requirement
A gradient long enough to separate it. No mass spectrometer will.

open-chain (reduced disulfide, +2 Da)

Retention offset from the main peak
-0.54 min on RG-2
Mass difference
+2.016 Da
Reported in
30 of 33 records (91 %)
Level when reported
median 0.10 %, max 1.06 %
Resolution requirement
Baseline-resolved on the reference method.

desmopressin dimer

Retention offset from the main peak
+2.24 min on RG-2
Mass difference
+1066.411 Da
Reported in
28 of 33 records (85 %)
Level when reported
median 0.12 %, max 0.43 %
Resolution requirement
Baseline-resolved on the reference method.

des-amino artefact (+16 Da)

Retention offset from the main peak
-0.30 min on RG-2
Mass difference
+15.995 Da
Reported in
27 of 33 records (82 %)
Level when reported
median 0.08 %, max 1.01 %
Resolution requirement
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.

  • disulfide reduction
  • epimerisation at Arg8