AssayIndex
Cross-section

Selank impurity profile

Every named species the index has reported alongside Selank, 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.

112 recordsmedian 99.13 %spec 99.0 %
Median total impurities 0.86% n=112
Median largest single 0.41% n=112
Worst single observed 1.40% n=112
Named species observed 4 / 4 n=4
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
tuftsin fragment (−417 Da)-0.62-417.23596%0.251.40
acetyl adduct (+42 Da)+0.34+42.01194%0.100.85
diketopiperazine (−18 Da)+0.18-18.01188%0.190.81
des-Thr (−101 Da)-0.26-101.04880%0.151.39

tuftsin fragment (−417 Da)

Retention offset from the main peak
-0.62 min on RG-2
Mass difference
-417.235 Da
Reported in
108 of 112 records (96 %)
Level when reported
median 0.25 %, max 1.40 %
Resolution requirement
Baseline-resolved on the reference method.

acetyl adduct (+42 Da)

Retention offset from the main peak
+0.34 min on RG-2
Mass difference
+42.011 Da
Reported in
105 of 112 records (94 %)
Level when reported
median 0.10 %, max 0.85 %
Resolution requirement
Baseline-resolved on the reference method.

diketopiperazine (−18 Da)

Retention offset from the main peak
+0.18 min on RG-2
Mass difference
-18.011 Da
Reported in
98 of 112 records (88 %)
Level when reported
median 0.19 %, max 0.81 %
Resolution requirement
Close-eluting — resolution below 1.2 is common and the peaks merge on short gradients.

des-Thr (−101 Da)

Retention offset from the main peak
-0.26 min on RG-2
Mass difference
-101.048 Da
Reported in
90 of 112 records (80 %)
Level when reported
median 0.15 %, max 1.39 %
Resolution requirement
Close-eluting — resolution below 1.2 is common and the peaks merge on short gradients.

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.

  • diketopiperazine formation from Pro-rich sequence
  • no oxidative liability