Determination of Main Products of Direct Hydroalkylation of Benzene by Gas Chromatography

A gas chromatographic analysis method for the products from direct hydroalkylation of benzene has been established. The chromatographic conditions were as follows: AT.FFAP column (50 m×0.32 mm×0.50 μm), hydrogen flame detector, split ratio: 50∶1, injector temperature: 180 ℃, detector temperature: 200 ℃, column temperature programmed: initial temperature was kept at 80 ℃ for 4 min, then heated to 180 ℃ at 15 ℃/min and kept for 8 min. The injection volume was 0.2 μL. Under these conditions, methyl cyclopentane, cyclohexane, cyclohexene, benzene, cyclohexylbenzene and dicyclohexylbenzene were effectively separated, and the detection limits were 1.4×10^-7, 1.4×10^-7, 1.4×10^-7, 1.6×10^-7, 2.7×10^-7 and 5.3×10^-6 mg/L, respectively, the limits of detection and quantification were low. The linear relationship of all substances was good. The correlation coefficient r was above 0.996. The method is simple and accurate, and can be used for the determination direct hydroalkylation of benzene of the reaction products.