IGF-1 LR3 impurity profile
Every named species the index has reported alongside IGF-1 LR3, 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
1.72%
n=118
Median largest single
0.95%
n=118
Worst single observed
2.06%
n=118
Named species observed
5 / 5
n=5
| Named species | ΔRT (min) | Δ mass (Da) | Seen in | Median % area | Max % area |
|---|---|---|---|---|---|
| disulfide-scrambled isomer | +0.62 | mass-identical | 100% | 0.36 | 2.06 |
| truncated (1-70) | -1.94 | -1385.688 | 100% | 0.13 | 1.61 |
| aggregated dimer | +3.20 | +9105.241 | 100% | 0.13 | 1.33 |
| oxidised Met59 (+16 Da) | -0.72 | +15.995 | 98% | 0.22 | 1.75 |
| des-13-residue N-extension (native IGF-1) | -2.24 | -1441.712 | 97% | 0.19 | 1.70 |
disulfide-scrambled isomer
- Retention offset from the main peak
- +0.62 min on RG-2
- Mass difference
- mass-identical — chromatography only
- Reported in
- 118 of 118 records (100 %)
- Level when reported
- median 0.36 %, max 2.06 %
- How it separates
- Chromatography only. A gradient long enough to separate it; no mass spectrometer of any resolution will.
truncated (1-70)
- Retention offset from the main peak
- -1.94 min on RG-2
- Mass difference
- -1385.688 Da
- Reported in
- 118 of 118 records (100 %)
- Level when reported
- median 0.13 %, max 1.61 %
- How it separates
- Baseline-resolved on the reference method.
aggregated dimer
- Retention offset from the main peak
- +3.20 min on RG-2
- Mass difference
- +9105.241 Da
- Reported in
- 118 of 118 records (100 %)
- Level when reported
- median 0.13 %, max 1.33 %
- How it separates
- Baseline-resolved on the reference method.
oxidised Met59 (+16 Da)
- Retention offset from the main peak
- -0.72 min on RG-2
- Mass difference
- +15.995 Da
- Reported in
- 116 of 118 records (98 %)
- Level when reported
- median 0.22 %, max 1.75 %
- How it separates
- Baseline-resolved on the reference method.
des-13-residue N-extension (native IGF-1)
- Retention offset from the main peak
- -2.24 min on RG-2
- Mass difference
- -1441.712 Da
- Reported in
- 115 of 118 records (97 %)
- Level when reported
- median 0.19 %, max 1.70 %
- How it separates
- 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 — three disulfides, many wrong ways to pair them
- aggregation on freeze–thaw
- deamidation at multiple Asn