ASTM D2269 Test Method for Evaluation of White Mineral Oils by Ultraviolet Absorption
8. Procedure
8.1 Transfer 25 mL of the mineral oil and 25 mL of hexane to a separatory funnel and mix. Add 5.0 mL of dimethyl sulfoxide and shake the mixture vigorously for at least 1 min. Allow to stand until the lower layer is clear.
8.2 Transfer the lower layer to a separatory funnel, add 2 mL of hexane and shake the mixture vigorously. Allow to stand until the lower layer is clear. Draw off the lower layer, designated as mineral oil extract, into a 1-cm cell.
8.3 Add 5.0 mL of dimethyl sulfoxide to 25 mL of hexane in a separatory funnel. Shake vigorously for at least 1 min and allow to stand until the lower layer is clear. Draw off this layer, designated as solvent control, into a 1-cm cell.
8.4 Determine the absorbance of the mineral oil extract compared to the solvent control through the range 260 to 350 nm inclusive.
