AssayIndex
Cross-section

Dihexa impurity profile

Every named species the index has reported alongside Dihexa, 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.

35 recordsmedian 99.84 %spec 98.5 %
Median total impurities 0.16% n=35
Median largest single 0.11% n=35
Worst single observed 0.52% n=35
Named species observed 4 / 4 n=4
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
des-hexanoyl (−98 Da)-2.42-98.07497%0.060.45
free acid (+1 Da)+0.26+0.98477%0.060.47
[D-Ile]-epimer-0.14mass-identical77%0.040.18
hexanoyl bis-adduct (+98 Da)+2.30+98.07454%0.060.52

des-hexanoyl (−98 Da)

Retention offset from the main peak
-2.42 min on RG-2
Mass difference
-98.074 Da
Reported in
34 of 35 records (97 %)
Level when reported
median 0.06 %, max 0.45 %
Resolution requirement
Baseline-resolved on the reference method.

free acid (+1 Da)

Retention offset from the main peak
+0.26 min on RG-2
Mass difference
+0.984 Da
Reported in
27 of 35 records (77 %)
Level when reported
median 0.06 %, max 0.47 %
Resolution requirement
Close-eluting — resolution below 1.2 is common and the peaks merge on short gradients.

[D-Ile]-epimer

Retention offset from the main peak
-0.14 min on RG-2
Mass difference
mass-identical — chromatography only
Reported in
27 of 35 records (77 %)
Level when reported
median 0.04 %, max 0.18 %
Resolution requirement
A gradient long enough to separate it. No mass spectrometer will.

hexanoyl bis-adduct (+98 Da)

Retention offset from the main peak
+2.30 min on RG-2
Mass difference
+98.074 Da
Reported in
19 of 35 records (54 %)
Level when reported
median 0.06 %, max 0.52 %
Resolution requirement
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.

  • hexanoyl amide hydrolysis
  • C-terminal amide hydrolysis