1.1 ,This test method covers the determination of the purity of isophorone. This method also determines the impurities of the material in concentration level less than 0.5 mass ,%, which may include mesityl oxide (MSO), mesityl oxide-isomer, mesitylene, trimethyl cyclohexenone (TMCH), phorone, phorone-isomer, xylitone, and tetralone.