| Identifier | a-L100-S |
|---|---|
| ¹H NMR, LA fraction | 100 % |
| SEC-RI, polystyrene-equivalent Mn | 16.5 ± 0.4 kDa |
| SEC-RI, polystyrene-equivalent Mw | 28.7 ± 0.6 kDa |
| SEC-RI, dispersity | 1.74 ± 0.01 |
Masashi Serizawa, Rick van den Hurk, Stefan van Berkel, Pieter van Delft, Bob W. J. Pirok, Ron A. H. Peters, Peter J. Schoenmakers, Andrea F. G. Gargano. “End-group-selective size-exclusion chromatography–mass spectrometry of poly(lactic acid) and poly(lactide-co-glycolide) polymers.” ChemRxiv (). https://doi.org/10.26434/chemrxiv.15007490/v1
Mobile-phase method-performance comparisons and the selected optimal composition were not retained
| Identifier | e-L100-M |
|---|---|
| ¹H NMR, LA fraction | 100 % |
| SEC-RI, polystyrene-equivalent Mn | 34.0 ± 1.0 kDa |
| SEC-RI, polystyrene-equivalent Mw | 60.3 ± 1.5 kDa |
| SEC-RI, dispersity | 1.77 ± 0.01 |
| Identifier | a-L100-M |
|---|---|
| ¹H NMR, LA fraction | 100 % |
| SEC-RI, polystyrene-equivalent Mn | 41.3 ± 0.3 kDa |
| SEC-RI, polystyrene-equivalent Mw | 69.7 ± 0.2 kDa |
| SEC-RI, dispersity | 1.69 ± 0.01 |
| Identifier | e-L100-S |
|---|---|
| Conventional SEC, Mn | 16.0 kDa |
| esSEC–MS, full BPC range | 0–20 min |
| esSEC–MS, non-acid-terminated region | 3.5–5.0 min |
| esSEC–MS, acid-terminated region | 15.0–17.0 min |
| Mass spectra extracted from the non-acid-terminated region | 4.1, 4.3, and 4.5 min |
| Mass spectra extracted from the acid-terminated region | 15.5, 15.7, and 15.9 min |
| Non-acid-terminated region assignments | Ester-terminated PLA and cyclic PLA |
| Acid-terminated region assignment | Acid-terminated PLA |
| Identifier | a-L100-S |
|---|---|
| Conventional SEC | New peak after reaction; product structure could not be assigned |
| esSEC–MS BPC, new peak | Between 4 and 5 min; dominates the chromatogram |
| New peak assignment | Non-acid-terminated product (cyclic PLA) |
| Later peak assignment | Starting polymer (acid-terminated PLA) |
| Mass spectrum extraction time | 4.5 min |
| Mass spectrum assignment | Cyclic PLA with characteristic ion series corresponding to non-acid-terminated species |
| Mass spectrum ion-series labels | C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18, and C19 |
| Identifier | e-L75-S |
|---|---|
| Initial composition | 75 % LA, 25 % GA |
| Ester-terminated PLGA fraction | 4.3 min; LA% 72.9 % |
| Cyclic PLGA fraction | 4.3 min; LA% 82.0 % |
| Identifier | e-L75-S |
|---|---|
| Acid-terminated PLGA fraction | 15.7 min; LA% 90.5 % |
| Ester-terminated PLGA fraction | 4.3 min; LA% 87.2 % |
| Cyclic PLGA fraction | 4.3 min; LA% 89.8 % |
| Acid-terminated species composition | Enriched in LA relative to the initial material |
| Ester-terminated species composition | Shifted toward higher LA fractions after degradation |