Semax impurity profile
Every named species the index has reported alongside Semax, 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
0.54%
n=216
Median largest single
0.31%
n=216
Worst single observed
1.35%
n=216
Named species observed
4 / 4
n=4
| Named species | ΔRT (min) | Δ mass (Da) | Seen in | Median % area | Max % area |
|---|---|---|---|---|---|
| Met1 sulfoxide (+16 Da) | -0.36 | +15.995 | 95% | 0.16 | 1.04 |
| des-Met (−131 Da) | +0.20 | -131.040 | 92% | 0.08 | 0.87 |
| diketopiperazine (−18 Da) | +0.16 | -18.011 | 88% | 0.12 | 1.35 |
| N-acetyl semax (+42 Da) | +0.42 | +42.011 | 87% | 0.11 | 0.91 |
Met1 sulfoxide (+16 Da)
- Retention offset from the main peak
- -0.36 min on RG-2
- Mass difference
- +15.995 Da
- Reported in
- 205 of 216 records (95 %)
- Level when reported
- median 0.16 %, max 1.04 %
- How it separates
- Baseline-resolved on the reference method.
des-Met (−131 Da)
- Retention offset from the main peak
- +0.20 min on RG-2
- Mass difference
- -131.040 Da
- Reported in
- 198 of 216 records (92 %)
- Level when reported
- median 0.08 %, max 0.87 %
- 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.
diketopiperazine (−18 Da)
- Retention offset from the main peak
- +0.16 min on RG-2
- Mass difference
- -18.011 Da
- Reported in
- 191 of 216 records (88 %)
- Level when reported
- median 0.12 %, max 1.35 %
- 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.
N-acetyl semax (+42 Da)
- Retention offset from the main peak
- +0.42 min on RG-2
- Mass difference
- +42.011 Da
- Reported in
- 187 of 216 records (87 %)
- Level when reported
- median 0.11 %, max 0.91 %
- 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.
- Met1 oxidation — an N-terminal methionine on a hygroscopic cake is a bad combination
- diketopiperazine formation