Faecal sterols determination in wastewater and surface water

A simplified method to detect faecal sterols, as an alternative assessment of environmental faecal pollution is proposed. The aim of this study is the development of a method to determine sterols in water samples avoiding sample filtration through glass fibre filter. The method is based on a liquid–liquid extraction and a final GC–FID determination. The quantified sterols are coprostanol and 24-ethylcoprostanol, while 5α-cholestane is used as internal standard. The recovery of coprostanol and 24-ethylcoprostanol in wastewater ranges from 90 to 100% and the detection limit is 1–2 μg l−1. Moreover the method proved to be useful for the sterols determination in surface water too.