Sodium and Potassium are used as reaction catalysts in the production of biodiesel. If not removed from the finished product, Sodium and Potassium may be present as abrasive solids or soluble metallic soaps. Sodium and Potassium may have the same effects as Calcium and Magnesium. Sodium and Potassium analysis is performed in accordance with EN 14538.
ASTM D6751 Requirement: a maximum of 5ppm (wt/wt) combined sodium and potassium content.