AssayIndex
Cross-section

GHRP-6 impurity profile

Every named species the index has reported alongside GHRP-6, 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.

169 recordsmedian 99.65 %spec 99.0 %
Median total impurities 0.35% n=169
Median largest single 0.19% n=169
Worst single observed 1.46% n=169
Named species observed 4 / 4 n=4
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
[D-Trp]-epimer-0.12mass-identical93%0.061.46
oxidised Trp (+16 Da)-0.34+15.99585%0.090.88
bis-oxidised Trp (+32 Da)-0.58+31.99076%0.061.35
des-Lys (−128 Da)-0.22-128.09565%0.091.09

[D-Trp]-epimer

Retention offset from the main peak
-0.12 min on RG-2
Mass difference
mass-identical — chromatography only
Reported in
157 of 169 records (93 %)
Level when reported
median 0.06 %, max 1.46 %
Resolution requirement
A gradient long enough to separate it. No mass spectrometer will.

oxidised Trp (+16 Da)

Retention offset from the main peak
-0.34 min on RG-2
Mass difference
+15.995 Da
Reported in
144 of 169 records (85 %)
Level when reported
median 0.09 %, max 0.88 %
Resolution requirement
Baseline-resolved on the reference method.

bis-oxidised Trp (+32 Da)

Retention offset from the main peak
-0.58 min on RG-2
Mass difference
+31.990 Da
Reported in
129 of 169 records (76 %)
Level when reported
median 0.06 %, max 1.35 %
Resolution requirement
Baseline-resolved on the reference method.

des-Lys (−128 Da)

Retention offset from the main peak
-0.22 min on RG-2
Mass difference
-128.095 Da
Reported in
110 of 169 records (65 %)
Level when reported
median 0.09 %, max 1.09 %
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.

  • double Trp oxidation — GHRP-6 has two, and both go
  • C-terminal amide hydrolysis