Correlations of Henry's law gas-solid virial coefficients and chromatographic retention times for hydrocarbons and halocarbons adsorbed on carbopack C carbon

Second gas-solid virial coefficients were determined at 403.5 +/- 0.5 K for 6 adsorbates, including butane, chloroform, trichlorofluoromethane (Freon 11), bromochloromethane, 1-chloro-2-methylpropane, and dibromodifluorometha ne. For another 11 adsorbates, including dichlorodifluoromethane (Freon 12) , chlorodifluoromethane (Freon 22), methyl chloride, methylene chloride, pr opane, n-pentane, n-hexane, carbon tetrachloride, 1,2-dichloropropane, buty l chloride, and cyclohexane, B-2s was measured over a range of temperatures between 308 and 494 K. These values were found using gas-solid chromatogra phy with Carbopack C (Supelco Inc.), a graphitized carbon black powder, as the adsorbent. We find that both the In B-2s values and the gas-solid inter action energies are effectively correlated with adsorbate-calculated molar refractivity, r(2) = 0.947 and r(2) = 0.964, respectively. Dipole moment al one provides a nearly random correlation of In B-2s and, if used with molar refractivity, gives r(2) = 0.970 for the 17 hydrocarbon and alkyl halide ( halocarbon) adsorbates. A theoretical equation was developed that predicts a quantitative structure retention relationship (QSRR) used to correlate In B-2s values with molar refractivity. B-2s values are directly proportional to the retention times of the adsorbates. Using one-surface and two-surfac e models, a calculation of the surface area of the Carbopack C for each of the 17 adsorbates provided a check on the consistency of the analysis as th e adsorbate was varied. (C) 1999 Academic Press.