This document describes the analytical procedures used to determine the content of C3A in the clinker starting from a chemical analysis on cement. The method can be applied to CEM type I and IV for the determination of the requirement of C3A@ as defined on EN 197?1. This document describes two methods@ traditional wet and XRF analysis (EN 196?2)@ which can be considered to be equivalent@ in the scope of this CEN/TR 17365@ for the determination of Al2O3@ Fe2O3 and SO3. The same methods are described in EN 196?2@ but for the scope of this document@ the X-ray fluorescence (XRF) is the preferred method to be used for the determination of Al2O3@ Fe2O3 and SO3.