ARA-290 impurity profile
Every named species the index has reported alongside ARA-290, 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
0.58%
n=91
Median largest single
0.28%
n=91
Worst single observed
1.58%
n=91
Named species observed
4 / 4
n=4
| Named species | ΔRT (min) | Δ mass (Da) | Seen in | Median % area | Max % area |
|---|---|---|---|---|---|
| deamidated (+1 Da) | -0.22 | +0.984 | 93% | 0.10 | 1.58 |
| acetyl adduct (+42 Da) | +0.40 | +42.011 | 90% | 0.08 | 0.71 |
| des-Gln truncate (−128 Da) | -0.30 | -128.059 | 89% | 0.13 | 0.64 |
| [D-Ser]-diastereomer | -0.12 | mass-identical | 87% | 0.08 | 0.47 |
deamidated (+1 Da)
- Retention offset from the main peak
- -0.22 min on RG-2
- Mass difference
- +0.984 Da
- Reported in
- 85 of 91 records (93 %)
- Level when reported
- median 0.10 %, max 1.58 %
- 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.
acetyl adduct (+42 Da)
- Retention offset from the main peak
- +0.40 min on RG-2
- Mass difference
- +42.011 Da
- Reported in
- 82 of 91 records (90 %)
- Level when reported
- median 0.08 %, max 0.71 %
- How it separates
- Baseline-resolved on the reference method.
des-Gln truncate (−128 Da)
- Retention offset from the main peak
- -0.30 min on RG-2
- Mass difference
- -128.059 Da
- Reported in
- 81 of 91 records (89 %)
- Level when reported
- median 0.13 %, max 0.64 %
- How it separates
- Baseline-resolved on the reference method.
[D-Ser]-diastereomer
- Retention offset from the main peak
- -0.12 min on RG-2
- Mass difference
- mass-identical — chromatography only
- Reported in
- 79 of 91 records (87 %)
- Level when reported
- median 0.08 %, max 0.47 %
- 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.
- Asn/Gln deamidation
- no oxidative liability