1.1 ,This test method covers the determination of aluminum, chromium, cobalt, titanium, iron, manganese, molybdenum, sodium and nickel in purified terephthalic acid (PAT) by graphite furnace atomic absorption (GFAA) spectrometry. It is applicable to PAT samples containing sodium, chromium, cobalt, titanium, manganese, molybdenum and nickel over 0.004 mg/kg, and iron and aluminum over 0.054 mg/kg.