AssayIndex
Cross-section

IGF-1 DES (1-3) impurity profile

Every named species the index has reported alongside IGF-1 DES (1-3), 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.

15 recordsmedian 99.12 %spec 95.0 %
Median total impurities 0.88% n=15
Median largest single 0.55% n=15
Worst single observed 1.19% n=15
Named species observed 4 / 4 n=4
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
full-length IGF-1 (+343 Da)+0.48+342.166100%0.090.89
disulfide-scrambled isomer+0.58mass-identical100%0.240.80
des(1-4) over-truncate (−87 Da)-0.36-87.032100%0.321.19
aggregated dimer+3.05+7365.719100%0.050.31

full-length IGF-1 (+343 Da)

Retention offset from the main peak
+0.48 min on RG-2
Mass difference
+342.166 Da
Reported in
15 of 15 records (100 %)
Level when reported
median 0.09 %, max 0.89 %
How it separates
Baseline-resolved on the reference method.

disulfide-scrambled isomer

Retention offset from the main peak
+0.58 min on RG-2
Mass difference
mass-identical — chromatography only
Reported in
15 of 15 records (100 %)
Level when reported
median 0.24 %, max 0.80 %
How it separates
Chromatography only. A gradient long enough to separate it; no mass spectrometer of any resolution will.

des(1-4) over-truncate (−87 Da)

Retention offset from the main peak
-0.36 min on RG-2
Mass difference
-87.032 Da
Reported in
15 of 15 records (100 %)
Level when reported
median 0.32 %, max 1.19 %
How it separates
Baseline-resolved on the reference method.

aggregated dimer

Retention offset from the main peak
+3.05 min on RG-2
Mass difference
+7365.719 Da
Reported in
15 of 15 records (100 %)
Level when reported
median 0.05 %, max 0.31 %
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.

  • disulfide scrambling
  • over-digestion to des(1-4) during production