AbstractSqualene was determined by HPLC using octadecylbenzene (ODB) as an internal standard. Squalene and ODB were monitored at 210nm. The retention times of squalene and ODB were 7.59 and 8.54min, respectively. Squalene was determined from the peak area ratios of squalene/ODB detected at 210nm. After treatment with 0.5M KOH containing ethanol at 90°C for 1h, squalene in the saponified lipid fraction was extracted using n-hexane. No interfering peak was observed. Linearity of this method was observed in the range 80–900 ng. ODB is useful as an internal standard for squalene determinations.