氟化氢（HF）烷基化的再生器底部通常是两相系统。下相相对富含HF，含量约30-40%；上层基本上是碳氢化合物，含有少量HF（约0-5%）。富HF下相的含水量通常小于10%，上相的含水量通常小于5%。该方法适用于两种样品中水分的测定。油中的不饱和物不会干扰水的滴定。

Regenerator bottoms from hydrogen fluoride (HF) alkylation are often 2-phase systems. The lower phase is relatively rich in HF, containing about 30-40%; and the upper phase is essentially hydrocarbon containing small concentrations (about 0-5%) of HF. The water content of the HF-rich lower phase is usually less than 10%, and that of the upper phase is usually less than 5%. This method is satisfactory for the determination of water in both types of samples. The unsaturates present in the oil do not interfere in the titration for water.