This method is for determining sodium in petroleum distillatefractions, No. 2 fuel oil and lighter, over a concentration rangeof 0.03 ppm to about 1 wt-%. Sodium in samples may result, forexample, from entrainment of aqueous droplets from a causticwashing operation or may be present as an oil-soluble salt.Analyses can be made for: (a) total sodium, which includessuspended alkali plus oil-soluble salts, and (b) oil-soluble sodiumsalts.

The sodium content of the heavier distillates, whole crude, orresidual oils should be determined by means of a wet-ashingtechnique, such as described in UOP Method 391.