This method is for determining hydrogen fluoride (HF) in HF alkylation regenerator bottoms. The bottoms material can be either a single or 2-phase system, the upper phase in a 2-phase system is rich in organic material and contains little HF, while the lower phase is rich in HF. The lower phase may contain large concentrations of water when there is appreciable water present in any of the feed streams. This method is applicable to both types of samples.