GHRP-2 impurity profile
Every named species the index has reported alongside GHRP-2, 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.
Median total impurities
0.78%
n=97
Median largest single
0.38%
n=97
Worst single observed
1.40%
n=97
Named species observed
4 / 4
n=4
| Named species | ΔRT (min) | Δ mass (Da) | Seen in | Median % area | Max % area |
|---|---|---|---|---|---|
| oxidised Trp (+16 Da) | -0.36 | +15.995 | 97% | 0.19 | 1.40 |
| C-terminal free acid (+1 Da) | +0.16 | +0.984 | 96% | 0.12 | 1.02 |
| des-Lys (−128 Da) | -0.24 | -128.095 | 95% | 0.11 | 0.88 |
| [D-2-Nal]-epimer | -0.14 | mass-identical | 94% | 0.13 | 0.92 |
oxidised Trp (+16 Da)
- Retention offset from the main peak
- -0.36 min on RG-2
- Mass difference
- +15.995 Da
- Reported in
- 94 of 97 records (97 %)
- Level when reported
- median 0.19 %, max 1.40 %
- Resolution requirement
- Baseline-resolved on the reference method.
C-terminal free acid (+1 Da)
- Retention offset from the main peak
- +0.16 min on RG-2
- Mass difference
- +0.984 Da
- Reported in
- 93 of 97 records (96 %)
- Level when reported
- median 0.12 %, max 1.02 %
- Resolution requirement
- Close-eluting — resolution below 1.2 is common and the peaks merge on short gradients.
des-Lys (−128 Da)
- Retention offset from the main peak
- -0.24 min on RG-2
- Mass difference
- -128.095 Da
- Reported in
- 92 of 97 records (95 %)
- Level when reported
- median 0.11 %, max 0.88 %
- Resolution requirement
- Close-eluting — resolution below 1.2 is common and the peaks merge on short gradients.
[D-2-Nal]-epimer
- Retention offset from the main peak
- -0.14 min on RG-2
- Mass difference
- mass-identical — chromatography only
- Reported in
- 91 of 97 records (94 %)
- Level when reported
- median 0.13 %, max 0.92 %
- Resolution requirement
- A gradient long enough to separate it. No mass spectrometer 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.
- Trp oxidation
- C-terminal amide hydrolysis