Thermal conductivity detection relative molar response factors for halogenated compounds

Relative molar response (RMR) factors for the thermal conductivity detector have been determined for a number of halogenated compounds. The compounds investigated included seven gases, namely CHF3, CBrF3, CH3Cl, CHClF2, C2HClF4, C3F8 and C4F10, and seven liquids, 2,3-dichloro-1-propene, 1-chloro-2-methyl-1-propene, 1,1,1-trichloroethane, m-dichlorobenzene, 1-bromo-3-chloropropane, 1-bromo-3-chloro-2-methylpropane and 2-bromopropane. Experimentally determined RMR values for these compounds were compared to theoretical predictions to examine the suitability of a predictive technique for halogenated compounds. Good agreement with predicted values has been found between both experimental and literature data, indicating that the predictive technique is applicable for halogenated species. The accuracy of the predictive technique is excellent for low-molecular-mass halogenated compounds, with the accuracy decreasing for molecules with more carbon atoms, molecules with iodine atoms and unsaturated halocarbons. An analysis of the relative errors associated with gas chromatographic quantification using assumed and predicted RMR factors was also undertaken. The predictive technique was found to provide a good estimation of RMR factors for compounds with limited response data