This International Standard specifies a method for pretreatment of soil samples by freeze-drying for subsequent analysis. This International Standard is applicable to soil samples for subsequent determination of elements or organic compounds recognized as non-volatile under freeze-drying conditions. Generally, this International Standard can also be applied to samples from sludges and sediments. This method is also applicable as a first step for the determination of dry matter (or water) content, for instance in the case of samples with high water content.