McReynolds constants of GC stationary phases
How much higher the retention index of five probes is on a phase than on squalane: benzene (X′), 1-butanol (Y′), 2-pentanone (Z′), 1-nitropropane (U′) and pyridine (S′). The larger the sum, the more polar the phase. The chromatogram simulator places non-alkanes with these values.
| Squalane | reference (nonpolar) | 0 | 0 | 0 | 0 | 0 | 0 |
|---|---|---|---|---|---|---|---|
| OV-101 | Dimethylpolysiloxane (nonpolar) | 17 | 57 | 45 | 67 | 43 | 229 |
| OV-17 | 50 % phenyl methylpolysiloxane (mid-polar) | 119 | 158 | 162 | 243 | 202 | 884 |
| Carbowax 20M | Polyethylene glycol (polar) | 322 | 536 | 368 | 572 | 510 | 2308 |
Probe indices on squalane (120 °C): benzene 653, 1-butanol 590, 2-pentanone 627, 1-nitropropane 652, pyridine 699. OV-101 corresponds to DB-1/HP-1-type dimethylpolysiloxane, OV-17 to 50 % phenyl methylpolysiloxane and Carbowax 20M to polyethylene glycol (WAX-type). Retention indices shift slightly with temperature.