AssayIndex
Cross-section

Vilon impurity profile

Every named species the index has reported alongside Vilon, 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.

11 recordsmedian 99.15 %spec 99.0 %
Median total impurities 0.85% n=11
Median largest single 0.43% n=11
Worst single observed 0.79% n=11
Named species observed 4 / 4 n=4
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
free lysine (−129 Da)-0.24-129.043100%0.090.34
free glutamic acid (−128 Da)-0.30-128.095100%0.230.65
diketopiperazine (−18 Da)+0.10-18.011100%0.130.79
Lys-Glu-Lys tripeptide (+128 Da)+0.14+128.095100%0.120.22

free lysine (−129 Da)

Retention offset from the main peak
-0.24 min on RG-2
Mass difference
-129.043 Da
Reported in
11 of 11 records (100 %)
Level when reported
median 0.09 %, max 0.34 %
Resolution requirement
Close-eluting — resolution below 1.2 is common and the peaks merge on short gradients.

free glutamic acid (−128 Da)

Retention offset from the main peak
-0.30 min on RG-2
Mass difference
-128.095 Da
Reported in
11 of 11 records (100 %)
Level when reported
median 0.23 %, max 0.65 %
Resolution requirement
Baseline-resolved on the reference method.

diketopiperazine (−18 Da)

Retention offset from the main peak
+0.10 min on RG-2
Mass difference
-18.011 Da
Reported in
11 of 11 records (100 %)
Level when reported
median 0.13 %, max 0.79 %
Resolution requirement
Close-eluting — resolution below 1.2 is common and the peaks merge on short gradients.

Lys-Glu-Lys tripeptide (+128 Da)

Retention offset from the main peak
+0.14 min on RG-2
Mass difference
+128.095 Da
Reported in
11 of 11 records (100 %)
Level when reported
median 0.12 %, max 0.22 %
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
  • hydrolysis to free amino acids