This document specifies a reference method for the determination of free sterols/stanols and steryl/stanol esters (0,1 % to 97 % mass fraction) in foods and dietary supplements containing added phytosterols and in phytosterol food additive concentrates. Milk and milk products (or fat coming from milk and milk products) are excluded from the scope of this document. This method does not apply to matrices that contain rice bran oil at concentrations of more than 20 % due to possible interferences in the gas chromatogram.