This test method covers the determination of the 4-carboxybenzaldehyde (4-CBA) and p-Toluic acid (p-TOL) in purified terephthalic acid (PTA) for industrial use by high performance liquid chromatography (HPLC). Purified terephthalic acid containing 4-carboxybenzaldehyde and p-Toluic acid at concentrations above 3 mg/kg and 10 mg/kg respectively can be detected by this test method.
Keywordspurified terephthalic acid (PTA);4-carboxybenzaldehyde (4-CBA); p-Toluic acid (p-TOL);high performance liquid chromatography (HPLC)
The presence of 4-CBA and P-Tol in PTA product needs to be well controlled, since the two impurities may affect the poly-condensation of terephthalic acid and ethylene glycol. The HPLC method will be adopted by PTA producers, consumers for quality control and trade.
The title and scope are in draft form and are under development within this ASTM Committee.Back to Top
Draft Under Development