Effect of the Carrier Gas on the Sensitivity of a Thermal-conductivity Detector in Gas Chromatography

Response of Thermal-Conductivity Cells in Gas Chromatography

“…For mixtures with helium, the factor is large because K-, is larger than K^; for mixtures with nitrogen or ethane, the factor is small because K2 is close to Ki. Thus, carrier gases of high thermal conductivity are preferred for maximum sensitivity in the detection of organic vapors (27). Because the conductivity of methanol is closer to that of the carrier gases, the factors for methanol mixtures are lower than for those with the hydrocarbons.…”

Gas Chromatography

“…Ray (182,183) demonstrated that carrier gases of low thermal conductivity offered highest sensitivity. This conclusion was challenged by a number of workers (68,78,195,203,236) who pointed out that for a constant wire temperature, carrier gases of hieh conductivity (helium) gave greater sensitivity with relatively constant response.…”