# The Thermodynamics of Chromatography - Other Thermodynamic Methods that are Used for Studying Chromatographic Systems > Optimum Operating Conditions for Chiral Separations in Liquid Chromatography > Page 67

Dead Volume = 2.785 ml

**Table 5
Retention Data for (S)– 4-Benzyl-2-Oxazolidinone**

Ethanol v/v |
V'_{B} (5˚C) |
V'_{B} (15˚C) |
V'_{B} (25˚C) |
V'_{B} (35˚C) |
V'_{B }(45˚C) |

10 % | 50.49 ml | 42.59 ml | 34.60 ml | 30.79 ml | 26.04 ml |

20 % | 22.61 ml | 18.75 ml | 15.39 ml | 13.00 ml | 11.45 ml |

30 % | 13.35 ml | 11.28 ml | 9.63 ml | 8.20 ml | 7.14 ml |

40 % | 9.51 ml | 7.85 ml | 6.46 ml | 5.52 ml | 4.90 ml |

50 % | 6.36 ml | 5.51 ml | 4.06 ml | 4.05 ml | 3.44 ml |

Dead Volume = 2.785 ml

The retention volume and the dead volume were measured in duplicate at 0.1, 0.2, 0.3, 0.4 and 0.5 volume fractions of ethanol in hexane and at temperatures of 5˚C, 15˚C, 25˚C, 35˚C and 45˚C respectively. The corrected retention volume was taken as the difference between the retention volume of the solute and the retention volume of the peak obtained for pure ethanol, for each solvent mixture. The retention data for each enantiomer, (S) and (R) 4-benzyl-2-oxazolidinone (taken as the average for each pair of measurements) at each temperature and for each solvent mixture is shown in tables 4 and 5.