1.1 This test method covers the determination of thiophene in refined benzene in the range from 0.5 mg/kg to 5.0 mg/kg. The range of the test method may be extended by modifying the sample injection volume, split ratios, calibration range, or sample dilution with thiophene-free solvent.1.2 This test method has been found applicable to benzene characteristic of the type described in Specifications D 2359 and D 4734 and may be applicable to other types or grades of benzene only after the