This European Standard specifies a method for the routine determination for aqua regia soluble elements as listed in Annex A and recommends suitable analytical methods for the determination of the extracted elements from soil improvers and growing media. Materials containing more than 34 % (m/m) organic matter will require treatment with additional nitric acid (see note 8.1, note 3) with high solute concentrations in extract solutions, spectral interference's and background enhancement should be expected.