IGF-1 DES (1-3) impurity profile
Every named species the index has reported alongside IGF-1 DES (1-3), 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
1.47%
n=28
Median largest single
0.98%
n=28
Worst single observed
1.65%
n=28
Named species observed
4 / 4
n=4
| Named species | ΔRT (min) | Δ mass (Da) | Seen in | Median % area | Max % area |
|---|---|---|---|---|---|
| disulfide-scrambled isomer | +0.58 | mass-identical | 100% | 0.32 | 0.74 |
| des(1-4) over-truncate (−87 Da) | -0.36 | -87.032 | 100% | 0.19 | 1.09 |
| full-length IGF-1 (+343 Da) | +0.48 | +342.166 | 93% | 0.17 | 1.22 |
| aggregated dimer | +3.05 | +7365.719 | 89% | 0.21 | 1.65 |
disulfide-scrambled isomer
- Retention offset from the main peak
- +0.58 min on RG-2
- Mass difference
- mass-identical — chromatography only
- Reported in
- 28 of 28 records (100 %)
- Level when reported
- median 0.32 %, max 0.74 %
- Resolution requirement
- A gradient long enough to separate it. No mass spectrometer will.
des(1-4) over-truncate (−87 Da)
- Retention offset from the main peak
- -0.36 min on RG-2
- Mass difference
- -87.032 Da
- Reported in
- 28 of 28 records (100 %)
- Level when reported
- median 0.19 %, max 1.09 %
- Resolution requirement
- Baseline-resolved on the reference method.
full-length IGF-1 (+343 Da)
- Retention offset from the main peak
- +0.48 min on RG-2
- Mass difference
- +342.166 Da
- Reported in
- 26 of 28 records (93 %)
- Level when reported
- median 0.17 %, max 1.22 %
- Resolution requirement
- Baseline-resolved on the reference method.
aggregated dimer
- Retention offset from the main peak
- +3.05 min on RG-2
- Mass difference
- +7365.719 Da
- Reported in
- 25 of 28 records (89 %)
- Level when reported
- median 0.21 %, max 1.65 %
- 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 scrambling
- over-digestion to des(1-4) during production