AssayIndex
Cross-section

Leuprolide impurity profile

Every named species the index has reported alongside Leuprolide, 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.

29 recordsmedian 99.28 %spec 98.5 %
Median total impurities 0.72% n=29
Median largest single 0.34% n=29
Worst single observed 1.01% n=29
Named species observed 4 / 4 n=4
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
des-ethylamide (+1 Da)+0.24-27.047100%0.120.35
oxidised Trp (+16 Da)-0.32+15.99597%0.101.01
ring-opened pGlu (+18 Da)-0.46+18.01197%0.160.63
[L-Leu6]-diastereomer-0.18mass-identical93%0.130.41

des-ethylamide (+1 Da)

Retention offset from the main peak
+0.24 min on RG-2
Mass difference
-27.047 Da
Reported in
29 of 29 records (100 %)
Level when reported
median 0.12 %, max 0.35 %
How it separates
Close-eluting on the reference method, and merged with the main peak on a short gradient. The index prints the resolution figure for such a pair and applies no criterion to it — where the two are not separated, what matters is that the integration convention is stated.

oxidised Trp (+16 Da)

Retention offset from the main peak
-0.32 min on RG-2
Mass difference
+15.995 Da
Reported in
28 of 29 records (97 %)
Level when reported
median 0.10 %, max 1.01 %
How it separates
Baseline-resolved on the reference method.

ring-opened pGlu (+18 Da)

Retention offset from the main peak
-0.46 min on RG-2
Mass difference
+18.011 Da
Reported in
28 of 29 records (97 %)
Level when reported
median 0.16 %, max 0.63 %
How it separates
Baseline-resolved on the reference method.

[L-Leu6]-diastereomer

Retention offset from the main peak
-0.18 min on RG-2
Mass difference
mass-identical — chromatography only
Reported in
27 of 29 records (93 %)
Level when reported
median 0.13 %, max 0.41 %
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.

  • ethylamide hydrolysis
  • pGlu ring opening
  • Trp oxidation