AssayIndex
Cross-section

PEG-MGF impurity profile

Every named species the index has reported alongside PEG-MGF, 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 97.92 %spec 92.0 %
Median total impurities 2.08% n=35
Median largest single 1.34% n=35
Worst single observed 2.91% n=35
Named species observed 4 / 4 n=4
Named speciesΔRT (min)Δ mass (Da)Seen inMedian % areaMax % area
free MGF (unconjugated)-5.62-5007.488100%0.441.00
di-PEGylated species+1.85+5000.000100%0.382.91
free mPEG+2.42-2886.512100%0.431.48
hydrolysed linker-0.72+18.011100%0.272.42

free MGF (unconjugated)

Retention offset from the main peak
-5.62 min on RG-2
Mass difference
-5007.488 Da
Reported in
35 of 35 records (100 %)
Level when reported
median 0.44 %, max 1.00 %
Resolution requirement
Baseline-resolved on the reference method.

di-PEGylated species

Retention offset from the main peak
+1.85 min on RG-2
Mass difference
+5000.000 Da
Reported in
35 of 35 records (100 %)
Level when reported
median 0.38 %, max 2.91 %
Resolution requirement
Baseline-resolved on the reference method.

free mPEG

Retention offset from the main peak
+2.42 min on RG-2
Mass difference
-2886.512 Da
Reported in
35 of 35 records (100 %)
Level when reported
median 0.43 %, max 1.48 %
Resolution requirement
Baseline-resolved on the reference method.

hydrolysed linker

Retention offset from the main peak
-0.72 min on RG-2
Mass difference
+18.011 Da
Reported in
35 of 35 records (100 %)
Level when reported
median 0.27 %, max 2.42 %
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.

  • linker hydrolysis releasing free MGF
  • PEG chain oxidation on prolonged air exposure