STUDIES ON THE METHODS OF ANALYSIS OF LOW-BOILING PHENOLS

Low-boiling phenols in low-temperature coal tar are important chemical raw materials. For the identification and determination of the individual phenol boiling below 210℃ in the low temperature coal tar, the methods of gas chromatography, liquid-liquid chromatography followed by ultra-violet analysis and fractional distillation followed by infrared analysis were evaluated and compared. For the same sample, the maximum deviation derived by these three methods was all within 2％. Although the first method was the most rapid one, but the last two gave more comprehensive results. For example, with the gas chromatography method, m-cresol, p-cresol and 2,6xylenol could not be separated, but with the last two methods the composition of each isomer could be determined.