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.
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.
purified terephthalic acid (PTA);4-carboxybenzaldehyde (4-CBA); p-Toluic acid (p-TOL);high performance liquid chromatography (HPLC)
The title and scope are in draft form and are under development within this ASTM Committee.
Citing ASTM Standards
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