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
0.55%
n=65
Median largest single
0.24%
n=65
Worst single observed
1.03%
n=65
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 | 91% | 0.13 | 1.03 |
| acetyl adduct (+42 Da) | +0.40 | +42.011 | 88% | 0.09 | 0.74 |
| des-Gln truncate (−128 Da) | -0.30 | -128.059 | 82% | 0.11 | 0.67 |
| [D-Ser]-diastereomer | -0.12 | mass-identical | 77% | 0.10 | 0.55 |
deamidated (+1 Da)
- Retention offset from the main peak
- -0.22 min on RG-2
- Mass difference
- +0.984 Da
- Reported in
- 59 of 65 records (91 %)
- Level when reported
- median 0.13 %, max 1.03 %
- Resolution requirement
- Close-eluting — resolution below 1.2 is common and the peaks merge on short gradients.
acetyl adduct (+42 Da)
- Retention offset from the main peak
- +0.40 min on RG-2
- Mass difference
- +42.011 Da
- Reported in
- 57 of 65 records (88 %)
- Level when reported
- median 0.09 %, max 0.74 %
- Resolution requirement
- 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
- 53 of 65 records (82 %)
- Level when reported
- median 0.11 %, max 0.67 %
- Resolution requirement
- 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
- 50 of 65 records (77 %)
- Level when reported
- median 0.10 %, max 0.55 %
- 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.
- Asn/Gln deamidation
- no oxidative liability