This method is for determining hydrogen fluoride (HF) in HFalkylation regenerator bottoms. The bottoms material can be eithera single or 2-phase system; the upper phase in a 2-phase system isrich in organic material and contains little HF, while the lowerphase is rich in HF. The lower phase may contain largeconcentrations of water when there is appreciable water present inany of the feed streams. This method is applicable to both types ofsamples.