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.

206 recordsmedian 99.54 %spec 99.0 %
Median total impurities 0.46% n=206
Median largest single 0.25% n=206
Worst single observed 1.11% n=206
Named species observed 4 / 4 n=4
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
[D-Trp]-epimer-0.12mass-identical93%0.080.95
oxidised Trp (+16 Da)-0.34+15.99591%0.130.89
des-Lys (−128 Da)-0.22-128.09588%0.061.11
bis-oxidised Trp (+32 Da)-0.58+31.99084%0.071.03

[D-Trp]-epimer

Retention offset from the main peak
-0.12 min on RG-2
Mass difference
mass-identical — chromatography only
Reported in
192 of 206 records (93 %)
Level when reported
median 0.08 %, max 0.95 %
How it separates
Chromatography only. A gradient long enough to separate it; no mass spectrometer of any resolution will.

oxidised Trp (+16 Da)

Retention offset from the main peak
-0.34 min on RG-2
Mass difference
+15.995 Da
Reported in
187 of 206 records (91 %)
Level when reported
median 0.13 %, max 0.89 %
How it separates
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
181 of 206 records (88 %)
Level when reported
median 0.06 %, max 1.11 %
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.

bis-oxidised Trp (+32 Da)

Retention offset from the main peak
-0.58 min on RG-2
Mass difference
+31.990 Da
Reported in
174 of 206 records (84 %)
Level when reported
median 0.07 %, max 1.03 %
How it separates
Baseline-resolved on the reference method.

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