described by the clapeyron clausius equation as it should be noted however that in practice deviations from equations 1 2 and 3 may be expected because of inter molecular forces therefore these relationships should be used only for guidance equations 1 2 and 3 may be combined to give equations 4 or 5 which relate the predicted vapor pressure p 0 for a component in a saturated mixture to temperature t as follows p 0 u2032 is the predicted vapor pressure for the second compound because compound concentration and hence chromatographic peak area is proportional to the vapor pressure equation 7 also applies to the peak area ratio as described more fully below fig3 shows chromatograms of the n dodecane and naphthalene test mix thermostatted over a range of temperatures the experimental conditions are given in table 1 fig4 shows a plot of area ratio naphthalene n dodecane to give a positive slope versus set temperature in u00b0 c the non smoothness in the plot may be caused by errors in the measurement or may be a true indication of varying vial temperature readings were taken with different vials in different carousel positions and at different times thus solving equation 8 for t the temperature of the vial can be.