This 4-part procedure is for the plant and laboratory sampling of liquid hydrogen fluoride streams and the analysis of these for acidity, water and acid-soluble oil. The method is applicable to fresh acid and alkylation process system acid. The acid-soluble oil determination is also applicable to regenerator bottoms samples. However, acidity and water determinations on regenerator bottoms samples must be conducted according to UOP Methods 379 and 382, respectively.