Abstract: An analytical method based on solid-phase microextraction (SPME) coupled with gas chromatography for the determination of organic impurities (2-methyl benzofuran and 2,4-diphenyl-4-methyl-1-pentene) in industrial phenol was developed. The SPME parameters such as extraction temperature, extraction time, and the desorption time were optimized. The optimized parameters were as follows: extraction temperature was 20 ℃, extraction time was 10 min, and desorption time was 30 s. The results demonstrated that the linearities of calibration curves were good in the ranges of 0.05~1.06 mg/L and 0.05~0.99 mg/L with the correlation coefficients of 0.990 and 0.992 for 2-methyl benzofuran and 2,4-diphenyl-4-methyl-1-pentene, respectively. The limits of detection (LODs) were 0.5 and 1.6 μg/L for 2-methyl benzofuran and 2,4-diphenyl-4-methyl-1-pentene, respectively. The relative recoveries were 104% and 113% for 2-methyl benzofuran and 2,4-diphenyl-4-methyl-1-pentene at the spiked level of 0.1 mg/L with triplicate determination. The method is simple, rapid and sensitive for the quantitative analysis of trace organic impurities in industrial phenol.

Key words: 2,4-diphenyl-4-methyl-1-pentene, 2-methyl benzofuran, gas chromatography, industrial phenol, solid-phase microextraction