ASTM D6144-17

1.1This test method covers the determination of the purity of AMS (α-methylstyrene) by gas chromatography. Calibration of the gas chromatography system is done by the external standard calibration technique.

1.2This test method has been found applicable to the measurement of impurities such as cumene, 3-methyl-2-cyclopentene-1-one, n-propylbenzene, tert-butylbenzene, sec-butylbenzene, cis-2-phenyl-2-butene, acetophenone, 1-phenyl-1-butene, 2-phenyl-2-propanol, trans-2-phenyl-2-butene, m-cymene, p-cymene, and phenol, which are common to the manufacturing process of AMS. The method has also been found applicable for the determination of para-tertiary-butylcatechol typically added as a stabilizer to AMS. The impurities in AMS can be analyzed over a range of 5 to 800 mg/kg by this method. (See Table 1.) The limit of quantitation for these these impurities averages 4 mg/kg, while the limit of detection averages 1.2 mg/kg. (See Table 1.)