FprEN 17705

SLOVENSKI STANDARD
oSIST prEN 17705:2023
01-maj-2023
Rastlinski biostimulanti - Določevanje fosfonatov
Plant biostimulants - Determination of phosphonates
Biostimulanzien für die pflanzliche Anwendung - Bestimmung von Phosphonaten
Biostimulants des végétaux - Dosage des phosphonates
Ta slovenski standard je istoveten z: prEN 17705
ICS:
65.080 Gnojila Fertilizers
oSIST prEN 17705:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 17705:2023
oSIST prEN 17705:2023
DRAFT
EUROPEAN STANDARD
prEN 17705
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2023
ICS 65.080 Will supersede CEN/TS 17705:2022
English Version
Plant biostimulants - Determination of phosphonates
Biostimulants des végétaux - Dosage des phosphonates Biostimulanzien für die pflanzliche Anwendung -
Bestimmung von Phosphonaten
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 455.
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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 17705:2023 E
worldwide for CEN national Members.

oSIST prEN 17705:2023
prEN 17705:2023 (E)
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Principle . 5
5 Reagents . 5
6 Apparatus . 6
7 Sampling . 6
8 Procedure . 7
8.1 Sample preparation . 7
8.2 Water extraction . 7
8.3 Preparation of the calibration solutions . 7
8.4 Measurement . 8
8.4.1 Instrument conditions . 8
8.4.2 IC-CD measurement . 8
9 Calculation and expression of the results . 9
9.1 Integration of peaks . 9
9.2 Concentration of phosphonates in test solutions . 9
10 Test report . 10
Annex A (informative) Separation of phosphonates from other interfering ions in a mixture
of standards . 11
Annex B (informative) Results of the inter-laboratory study . 12
B.1 Inter-laboratory tests . 12
B.2 Statistical results for determination of phosphonates . 12
Annex ZA (informative) Relationship of this European Standard and the essential
requirements of Regulation (EU) 2019/1009 making available on the market of EU
fertilising products aimed to be covered . 14
Bibliography . 15
oSIST prEN 17705:2023
prEN 17705:2023 (E)
European foreword
This document (prEN 17705:2023) has been prepared by Technical Committee CEN/TC 455 “Plant
Biostimulants”, the secretariat of which is held by AFNOR.
This document is currently submitted to the CEN enquiry.
This document will supersede CEN/TS 17705:2022.
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of EU
Directive(s) / Regulation(s).
For relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, which is an integral part
of this document.
oSIST prEN 17705:2023
prEN 17705:2023 (E)
Introduction
This document was prepared by the experts of CEN/TC 455 “Plant Biostimulants”. The European
Committee for Standardization (CEN) was requested by the European Commission (EC) to draft
European standards or European standardization deliverables to support the implementation of
Regulation (EU) 2019/1009 of 5 June 2019 laying down rules on the making available on the market of
EU fertilizing products (“FPR” or “Fertilising Products Regulation”).
This standardization request, presented as M/564 and M/564 Amd1, also contributes to the
Communication on “Innovating for Sustainable Growth: A Bio economy for Europe”. Working Group 4
“Other safety parameters” was created to develop a work programme as part of this request. Technical
committee CEN/TC 455 “Plant Biostimulants” was established to carry out the work programme that will
prepare a series of standards. The interest in biostimulants has increased significantly in Europe as a
valuable tool to use in agriculture. Standardization was identified as having an important role in order to
promote the use of biostimulants. The work of CEN/TC 455 seeks to improve the reliability of the supply
chain, thereby boosting the confidence of farmers, industry, and consumers in biostimulants, and will
promote and support commercialisation of the European biostimulant industry.
The preparation of this document is based on the Fertilising Products Standardization Request (M/564)
to CEN by the European Commission and the European Free Trade Association concerning a development
of the methods for analysis of fertilizers in the framework of Regulation (EU) 2019/1009.
This document describes an extraction and measurement for the determination of phosphonate
(phosphite) in plant biostimulants. It is based on a water extraction of the phosphonate (phosphite)
followed by ion chromatography with conductivity detection (IC-CD).
The ion chromatography with a conductivity detector (IC-CD) method can be used in well-equipped
analytical laboratories for the determination of different ions. In the field of fertilizing products, the
method is used and standardized for the determination of perchlorates in mineral fertilizers. The IC-CD
method can determine more ions simultaneously.
The legislative limit for phosphonate content is 0,5 % (mass fraction) and the method described in this
document was adapted to achieve this requirement and simultaneously to reduce interferences from
other co-extracted anions as much as possible.
The definition of phosphonates is not clearly stated in Regulation (EU) 2019/1009 and to avoid any
misunderstanding, the results are expressed as a content of phosphorus (P) bound in the form of free
water-soluble phosphonates (P-PO3).
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.
oSIST prEN 17705:2023
prEN 17705:2023 (E)
1 Scope
This document specifies a method for the extraction and determination of phosphonates (P-PO ) in plant
biostimulants using ion chromatography and conductivity detection (IC-CD).
This document is applicable to the fertilizing product blends belonging to PFC 7 where the EU fertilising
product plant biostimulant contained in the blend represents the highest % by mass in the blend. In case
of equal shares, the user may apply either this or the standard(s) applicable to the other component
product(s).
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.
EN 17704:— , Plant biostimulants — Determination of dry matter
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
phosphonates
salts derived from phosphonic acid (H3PO3)
4 Principle
A representative test portion of the sample is extracted with water. Phosphonate in the extract is
selectively separated from other compounds using ion chromatography (IC) and determined by a
conductivity detector (CD). External calibration is used for quantification of the amount of the
phosphonate.
5 Reagents
All reagents shall be of recognized analytical grade. The concentration of phosphonate in the reagents
and deionized water used shall be low enough not to affect the results of the determination.
5.1 Water with a specific conductivity not higher than 0,2 mS/m at 25 °C.
5.2 Phosphonate standard stock solution, r(P-PO ) = 1 000 mg/l is prepared by dissolving
commercially available sodium phosphite dibasic pentahydrate salt (M = 216,04 mol/l, purity ≥ 98 %).
w
For preparation the phosphonate standard stock solution 0,697 ± 0,001 g is weighed, transferred to
100 ml volumetric flask, fill with deionized water (5.1) to final volume and mix thoroughly.
5.3 Phosphonate standard solution, r(P-PO ) = 100 mg/l is prepared from a standard stock solution
(5.2) by appropriate dilution with deionized water (5.1). Pipette 10 ml of stock solution (5.2) to a 100ml
volumetric flask, fill with deionized water (5.1) to final volume and mix thoroughly.
5.4 Mobile phase, KOH cartridge for ion chromatography (commercially supplied). Concentration of
the KOH mobile phase is electrolytically generated in externally supplied deionized water (5.1).
Different mobile phase may be used according to the instructions of the manufacturer of the column.

Under preparation
oSIST prEN 17705:2023
prEN 17705:2023 (E)
−
5.5 Chloride standard, r(Cl ) = 1 000 mg/l – commercially available.
−
5.6 Nitrate standard, r(NO3 ) = 1 000 mg/l – commercially available.
−
5.7 Solution for checking chromatographic separation, r(P-PO ) = 10 mg/l, r(Cl and
−
NO3 ) = 50 mg/l is prepared by pipetting 1 ml of phosphonate standard stock solution (5.2), 5 ml of
chloride standard (5.5), 5 ml of nitrate standard (5.6) to 100ml volumetric flask and fill to final volume
with deionized water (5.1).
6 Apparatus
6.1 Common laboratory glassware and plastic.
6.2 Laboratory grinder, capable of grinding to a particle size less than 0,5 mm.
6.3 Analytical balance, accuracy ≤ 1 mg.
6.4 Shaker, rotary or horizontal shaker. Shaking shall prevent any settling of the sample during
extraction.
6.5 Extraction vessels, capacity 200 ml to 500 ml.
−1
6.6 Centrifuge (optional), for
...