prEN 17768

SLOVENSKI STANDARD
01-marec-2026
Organska in organsko-mineralna gnojila - Razklop z zlatotopko za določanje
elementov
Organic and organo-mineral fertilizers - Digestion by aqua regia for subsequent
determination of elements
Organische und organisch-mineralische Düngemittel - Aufschluss durch Königswasser
zur anschließenden Bestimmung der Elemente
Engrais organiques et organo-minéraux - Digestion à l’eau régale pour le dosage
ultérieur des éléments
Ta slovenski standard je istoveten z: prEN 17768
ICS:
65.080 Gnojila Fertilizers
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2026
ICS 65.080 Will supersede CEN/TS 17768:2022
English Version
Organic and organo-mineral fertilizers - Digestion by aqua
regia for subsequent determination of elements
Engrais organiques et organo-minéraux - Digestion à Organische und organisch-mineralische Düngemittel -
l'eau régale pour le dosage ultérieur des éléments Aufschluss durch Königswasser zur anschließenden
Bestimmung der Elemente
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 260.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17768:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 6
4 Principle . 6
5 Sampling and sample preparation . 6
6 Reagents . 6
7 Apparatus . 7
8 Procedure. 7
8.1 General . 7
8.2 Sample digestion . 7
8.3 Sample pre-concentration . 8
8.4 Blank test solution . 8
9 Test report . 8
Annex A (informative) Adjustment to different digestion procedures and measurement
apparatuses . 9
Bibliography . 11

European foreword
This document (prEN 17768:2026) has been prepared by Technical Committee CEN/TC 260 “Fertilizers
and liming materials”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede CEN/TS 17768:2022.
CEN/TS 17768:2022:
— The CEN Technical Specification has been adopted as a European Standard;
— Scope (Clause 1) updated including the clarification on fertilizing products blends and the addition of
further elements;
— Normative references (Clause 2) updated by addition of reference to prEN 17773 ;
— Terms and definitions added;
— Sampling and sample preparation (Clause 5) revised;
— Principle described more detailed by adding the number of hours necessary for boiling;
— Apparatus (Clause 7) widened to include information about measures avoiding contamination by
boron;
— Bibliography revised.
This document has been prepared under a Standardization Request addressed to CEN by the European
Commission. The Standing Committee of the EFTA States subsequently approves these requests for its
Member States.
Introduction
NOTE 1 Regulation (EU) 2019/1009 [1] specifies safety and quality requirements for component materials and
component material categories (CMCs) of fertilizing products available on the EU market.
NOTE 2 By-products within the meaning of Directive 2008/98/EC have been classified as CMC 11, thermal
oxidation materials or derivatives as CMC 13 and recovered high purity materials as CMC 15 in Regulation (EU)
2019/1009 [1].
Aqua regia is applied to digest different matrices for the subsequent determination of many elements.
For example, a multi-matrix standard for aqua regia extraction of soils, sludges and biowaste was
prepared by CEN/TC 444 “Environmental characterization of solid matrices” [2, 3]. A similar procedure
was applied for determination of aqua regia extractable contents of arsenic, mercury, cadmium,
chromium, nickel and lead in fertilizers and liming materials [4, 5, 6], for extraction of micronutrients
from mineral fertilizers [7] etc. CEN/TC 223 “Soil improvers and growing media” published a standard
for a similar procedure for soil improvers and growing media [8]. CEN/TC 455 “Plant Biostimulants”
published a standard for a similar procedure for plant biostimulants [9]. The interlaboratory study (ILS)
for plant biostimulants included also fertilizing product blends of these fertilizing products with some
organic and organo-mineral fertilizers. The ILS proved that the method is also suitable for these fertilizing
product blends.
Wide use of the aqua regia digestion, availability of the instruments and the possibility to merge the
standards for different matrices in future, were the main reasons for also applying this method of
digestion for organic and organo-mineral fertilizers. A simple pre-concentration procedure is a part of
this document to also cover the digestion of liquid samples with low dry matter content in the case that
the measurement method is not sufficiently sensitive. Annex A describes in detail the calculation of the
initial sample mass to be taken for the pre-concentration step to achieve concentrations of the individual
elements above the limit of quantification (LOQ).
WARNING — Persons using this document should be familiar with usual laboratory practice. This
document does not purport to address all of the safety issues, if any, associated with its use. It is the
responsibility of the user to establish appropriate health and safety practices and to ensure compliance
with any national regulatory conditions.
IMPORTANT — It is absolutely essential that tests conducted according to this document are carried out
by suitably trained staff.
1 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 the fertilizing products blends where a blend is a mix of at least two of the
following components: fertilizers, liming materials, soil improvers, growing media, inhibitors, plant
biostimulants, 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 fertilizer
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. 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.
1 2
The digests are suitable for analysis using prEN 17770 [11] and prEN 17769 [10].
This document is applicable and validated for several types of matrices as indicated in Annex A.
NOTE 1 Digestates prepared by the procedure given in this document can also be applied for determination of
other elements.
NOTE 2 Alternatively, inductively coupled plasma mass spectrometry (ICP-MS) can be used for the measurement
if the user proves that the method gives the same results.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
prEN 17773, Organic and organo- mineral fertilizers — Determination of the dry matter content
EN 12944-1, Fertilizers and liming materials — Vocabulary — Part 1: General terms
EN 12944-2, Fertilizers and liming materials — Vocabulary — Part2: Terms relating to fertilizers
EN 1482-2, Fertilizers, liming materials and inhibitors — Sampling and sample preparation — Part 2:
General sample preparation p
...