FprEN 17768

Organic and organo-mineral fertilizers - Digestion by aqua regia for subsequent determination of elements

Publication date:   Oct 29, 2026

Scope

This document specifies the procedure for digestion of different organic and organo-mineral fertilizers with aqua regia to enable a subsequent determination of arsenic (As), cadmium (Cd), copper (Cu), chromium (Cr), lead (Pb), nickel (Ni), boron (B), cobalt (Co), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn), mercury (Hg), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca), sulfur (S) and sodium (Na).
This document is applicable to the component materials “by-products”, when used as components of fertilizing products, as well as fertilizing product blends, where the blend is a mix of at least two of the following components: fertilizers, liming materials, soil improvers, growing media, inhibitors, plant bi-ostimulants, and where the following category: organic fertilizers, organo-mineral fertilizers is the highest % in the blend by mass or volume, or in the case of liquid form by dry mass. If the organic ferti-lizer or the organo-mineral fertilizer is not the highest % in the blend, the European Standard for the highest % of the blend applies. In case a fertilizing product blend is composed of components in equal quantity, the user decides which standard to apply.
NOTE 1 Variations in analytical methods for fertilizing product blends can lead to differing results as some components or matrix interactions can affect the outcome. Validation procedures have shown that developed standard methods are robust and reliable across diverse product compositions, but possible interferences and unexpected results when analysing fertilizing product blends are possible.
The digests are suitable for analysis using EN 17770 [11] and EN 17769 [10].
This document is applicable and validated for several types of matrices as indicated in Annex A of FprEN 17770:2026 [11].
NOTE 2 Digests prepared by the procedure given in this document can also be applied for determination of other elements.
NOTE 3 Alternatively, inductively coupled plasma mass spectrometry (ICP-MS) can be used for the measure-ment if the user proves that the method gives the same results.

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