Influence of analyte overloading on retention in gas-liquid chromatography: a molecular simulation view
Wick, CD; Siepmann, JI; Schures, MR
| HERO ID | 4865185 |
|---|---|
| In Press | No |
| Year | 2002 |
| Title | Influence of analyte overloading on retention in gas-liquid chromatography: a molecular simulation view |
| Authors | Wick, CD; Siepmann, JI; Schures, MR |
| Journal | Analytical Chemistry |
| Volume | 74 |
| Issue | 1 |
| Page Numbers | 37-44 |
| Abstract | In an attempt to elucidate the molecular basis for concentration (isotherm) effects on retention in gas-liquid chromatography, configurational-bias Monte Carlo simulations in the Gibbs ensemble were carried out to investigate changes in analyte partitioning caused by overloading a model chromatographic system with either an alkane or an alcohol. Squalane was used as the stationary-phase material, and the analytes included n-pentane, n-hexane, n-heptane, 1 -butanol, and 1-pentanol. Three systems were studied that differed in the mobile-phase composition: (i) a helium vapor, (ii) a n-hexane vapor, and (iii) a 1-pentanol-saturated helium vapor. While the amount of helium that partitions into the stationary phase is very small, both n-hexane and 1-pentanol partition strongly into and thereby swell the stationary phase. Although the swelling of the stationary phase leads to a reduction in the partition coefficients for the alkane solutes for both the n-hexane- and 1-pentanol-swollen stationary phases, the effects on the alcohol solutes differ markedly. Whereas saturation by n-hexane causes a decrease of the alcohol partition contants (to an extent similar to that for the alkane solutes), the saturation by 1-pentanol causes a dramatic increase of the alcohol partition coefficients; e.g., the Kovats index of 1-butanol increases by more than 150 Kovats units. The formation of hydrogen-bonded alcohol aggregates in the liquid phase is the microscopic origin for the dramatic effect of 1-pentanol saturation on the retention of alcohols. |
| Doi | 10.1021/ac0108717 |
| Pmid | 11795813 |
| Wosid | WOS:000173086200012 |
| Is Certified Translation | No |
| Dupe Override | No |
| Comments | Scopus URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-0036140159&doi=10.1021%2fac0108717&partnerID=40&md5=35335a8dd0ac3ae2914d8dfe8ad6ffa2 |
| Is Public | Yes |
| Language Text | English |