CEN/TC 260

Date: 2025-12

prEN 17775:2026

Secretariat: CEN/TC 260

Organic and organo-mineral fertilizers — Determination of the inorganic arsenic content

Organische und organisch-mineralische Düngemittel - Bestimmung des Gehalts an anorganischem Arsen

Engrais organiques et organo-minéraux - Détermination de la teneur en arsenic inorganique

CCMC will prepare and attach the official title page.

Contents Page

European foreword 3

Introduction 4

1 Scope 5

2 Normative references 5

3 Terms and definitions 5

4 Principle 6

5 Sampling 6

6 Reagents 6

7 Apparatus 8

8 Procedure 9

9 Calculation and expression of the results 12

10 Precision 13

11 Test report 14

Annex A (informative) Examples of typical chromatographic separation 15

Annex B (informative) Results of the inter-laboratory study 19

B.1 Inter-laboratory study 19

B.2 Statistical results for determination of inorganic arsenic 19

Bibliography 21

European foreword

This document (prEN 17775:2026) 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 17775:2022.

Compared to the previous edition, prEN 17775:2026 includes the following significant technical changes:

— the CEN Technical Specification has been adopted as a European Standard;

— Scope (Clause 1) updated including a clarification on fertilizing product blends;

— Normative references to dry matter content determination added;

— Normative references to sampling added;

— Terms and definitions revised;

— Test report revised;

— Bibliography revised;

— Annex A (Examples of typical chromatographic separation) revised;

— Annex B (Results of the inter-laboratory study) added.

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

The method is based on a mild acid oxidative extraction of the arsenic species followed by liquid chromatography (high performance liquid chromatography [HPLC] or ion chromatography [IC]) coupled to the element-specific detector ICP-MS (inductively coupled plasma mass spectrometer) for the determination of the mass fraction of inorganic arsenic (iAs).

Other standards developed for determination of inorganic arsenic content in plant biostimulants, animal feeding stuffs and foodstuffs were studied and considered as a basis of the described method [2], [3], [4], [5], [6].

The inter-laboratory study reflects the final statistical characteristics of the method for the determination of inorganic arsenic content in organic and organo-mineral fertilizers. The results are given in Annex B (informative).

To prove the compliance with existing limit values for inorganic arsenic in organic and organo-mineral fertilizers, there is the possibility to choose between:

• Using a test method determining the total arsenic content, as long as the result of the test shows a content below the limit value for inorganic arsenic. In such a case, it can be safely assumed that the organic fertilizer or the organo-mineral fertilizer complies with the limit value for inorganic arsenic.
• Using a test method which determines only inorganic arsenic content.

A preliminary determination of the total arsenic in aqua regia extracts by ICP-AES (inductively coupled plasma atomic emission spectrometry) according to prEN 17768 [8] and prEN 17770 [9] can reduce the number of the samples where the determination of iAs is necessary because if the content of aqua regia (total) extractable arsenic is lower than the legislative limit for iAs then the determination of iAs is not necessary. In case total As is measured and is presented above or equal the legislative limit for iAs, the content of inorganic As should be determined according to this document.

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.

This document specifies a method for extraction, separation, and determination of inorganic arsenic (iAs) in organic or organo-mineral fertilizers using anion-exchange high performance liquid chromatography (HPLC) or ion chromatography (IC) coupled to ICP-MS.

This document is applicable to fertilizing product 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 fertilizer or organo-mineral fertiliser 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.

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

prEN 12944‑1, Fertilizers, liming materials and inhibitors — Vocabulary — Part 1: General terms

prEN 12944‑2, Fertilizers, liming materials and inhibitors — Vocabulary — Part 2: Terms relating to fertilizers

EN 1482‑2, Fertilizers, liming materials and inhibitors — Sampling and sample preparation — Part 2: General sample preparation provisions

For the purposes of this document, the terms and definitions given in prEN 12944‑1 and prEN 12944‑2 and the following apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp/

— IEC Electropedia: available at https://www.electropedia.org/

3.1

analyte

parameter to be determined

3.2

blank calibration solution

solution prepared in the same way as the calibration solution but leaving out the analytes

3.3

blank test solution

solution prepared in the same way as the test sample solution but omitting the test portion

3.4

calibration solution

solution used to calibrate the instrument, prepared from stock solutions by adding acids, buffer, reference element and salts as needed

3.5

stock solution

solution with accurately known analyte concentration(s), prepared from pure chemicals

3.6

test sample solution

solution prepared after extraction or digestion of the test sample according to appropriate specifications

This document specifies a method for the determination of inorganic arsenic in organic or organo-mineral fertilizers. Inorganic arsenic consists of arsenite As(III) and arsenate As(V). A representative test portion of the sample is treated with a diluted nitric acid and hydrogen peroxide solution in a heated water bath. By this means the sample is solubilised, arsenic species are extracted into solution and As(III) is oxidized to As(V). The inorganic arsenic is selectively separated from other arsenic compounds using anion exchange HPLC (high performance liquid chromatography) coupled online to the element-specific detector ICP-MS (inductively coupled plasma mass spectrometer) for the determination of the mass fraction of the inorganic arsenic. External calibration with solvent matrix-matched standards is used for the quantification of the amount of the inorganic arsenic. Alternatively, IC (ion chromatography) coupled to ICP-MS can be used.

Sampling is not part of the method specified in this document. Recommended sampling methods are given in EN 1482‑1 [11] and in EN 1482‑3 [12].

It is important that the laboratory receives a sample that is representative of both the product under consideration and the given analysis. The sample should not have been damaged or changed during transport or storage.

Sample preparation shall be carried out in accordance with EN 1482‑2.

6.1 General

When using a method of high sensitivity like ICP-MS, the control of the blank levels of water, acid and other reagents is very important. The reagents shall be of adequate purity and of recognized analytical grade. The concentration of arsenic species in the reagents and water used shall be negligible and low enough not to affect the results of the determination. Generally, ultra-pure water and nitric acid of minimum p.a. quality is recommended.

6.2 Water, with an electrical conductivity not higher than 0,1 mS/m at 25 °C.

6.3 Nitric acid (HNO3), concentrated, ≥ 65 % (mass fraction), mass concentration of approximately ρ (HNO3) 1,4 g/ml.

Use only nitric acid available with high purity (minimum p.a. quality) in order to avoid potential contamination.

6.4 Hydrogen peroxide, H2O2 not less than 30 % (mass fraction).

High purity is essential to avoid potential contamination. Commercially available hydrogen peroxide for analysis should be tested for contamination of arsenic prior to use. It is necessary to prevent peroxide degradation and ensure the stability of the solution, this is in the discretion of the analyst to use only H₂O₂ of adequate quality.

6.5 Extraction solution, 0,1 mol/l HNO3 in 3 % (volume fraction) H2O2.

Add 6,5 ml of HNO₃ (6.3) and thereafter 100 ml of hydrogen peroxide (6.4) into 800 ml water (6.2) in a 1 000 ml volumetric flask. Fill the flask to the mark with water (6.2). This solution is prepared on the day of use.

It is recommended that the total volume needed for the analysis is estimated and only this amount is produced in the day of use.

6.6 Ammonium carbonate, (NH4)2CO3, mass fraction w ≥ 99,999 %, for preparation of the mobile phase solution.

6.7 Aqueous ammonia, (NH3(aq)), mass fraction w ≥ 25 %, for adjustment of pH in the mobile phase.

6.8 Methanol, (CH3OH), HPLC grade, for preparation of the mobile phase solution.

6.9 Mobile phase, e.g. 50 mmol/l ammonium carbonate in 3 % (volume fraction) methanol at pH 10,3.

Dissolve 4,80 g of ammonium carbonate (6.6) in approximately 800 ml water (6.2). Adjust the pH to 10,3 with aqueous ammonia (6.7) and add 30 ml of methanol (6.8) and then fill up to 1 000 ml with water (6.2). Prior to use filter the mobile phase solution through a 0,45 μm filter using a filtering device (7.4).

The optimal concentration of ammonium carbonate in the mobile phase depends on the analytical column used (e.g. brand, particle size and dimensions) and should be verified in advance. The appropriate concentration of ammonium carbonate (usually between 10 mmol/l to 50 mmol/l) is highly dependent on the column used and is up to the discretion of the analyst. It should fulfil the criteria for sufficient resolution of the arsenate peak.

Methanol is added to the mobile phase in order to enhance the signal intensity for arsenic. The concentration of methanol to achieve the highest signal to noise ratio depends on the instrument used and should be identified by the analyst.

NOTE 1 Different mobile phase can be also used according to the instructions of the manufacturer of the column but it is necessary to verify the optimal separation conditions.

NOTE 2 For example, Agilent^[1] column G3154–65001 with a guard column G3154–65002 and a mobile phase recommended for this column, as a mixture of potassium dihydrogen phosphate (KH₂PO₄) 2 mmol/l, ethylenediaminetetraacetic acid disodium salt dihydrate (EDTA disodium salt) 0,2 mmol/l, pH 6,0 adjusted with sodium hydroxide (NaOH) 1 mol/l, were successfully used for the analysis.

6.10 Arsenic (V) standard stock solution, with an arsenic (V) mass concentration of 1 000 mg/l.

The use of commercial standards of arsenic As(V), with a mass concentration of 1 000 mg/l is recommended.

6.11 Arsenic (V) standard solution I, with an arsenic (V) mass concentration of 10 mg/l in 2 % (volume fraction) HNO3.

Pipette 1 ml of arsenic standard stock solution (6.10) into a 100 ml volumetric flask. Add 2 ml of nitric acid (6.3), fill to the mark with water (6.2) and mix well. This solution is stable in a refrigerator at least one week.

6.12 Arsenic (V) standard solution II, with an arsenic (V) mass concentration of 1 mg/l.

Pipette 10 ml of arsenic standard solution I (6.11) into a 100 ml volumetric flask, fill to the mark with water (6.2) and mix well. This solution should be prepared on the same day of use.

6.13 Solution for checking chromatographic separation, containing organic arsenic compounds (e.g. 10 μg/l) monomethylarsenous acid (MMA), dimethylarsinic acid (DMA) and arsenobetaine (AB), as well as arsenate (e.g. 10 μg/l), arsenite (e.g. 10 μg/l) and chloride (e.g. 100 mg/l).

This solution is recommended to demonstrate satisfactory resolution of individual arsenic species, possible interferents and to find out how the chromatographic conditions should be optimized (e.g. by changing the mobile phase concentration or the mobile phase flow rate).

The solution shall be prepared in water (6.2), not in the extraction solution, to check the retention time of the individual arsenic species, their visual presentation in the chromatogram and how the peaks are separated.

7.1 Common laboratory glass and plastic ware.

Plastic volumetric flasks are recommended for the preparation of the mobile phase and calibration solutions. All glassware and plastic ware shall be adequately cleaned and stored to avoid any contamination.

7.2 Laboratory grinder, capable of grinding to a particle size less than 0,5 mm.

7.3 Analytical balance, capable of weighing to the nearest of 1 mg or better.

7.4 Filtering device, for filtration of mobile phase with a filter, pore size 0,45 μm.

7.5 Heated (shaking) water bath, capable of maintaining 90 °C.

Some fine materials can form a thin layer on the surface of the extraction solution and the contact of the sample with the extraction solution can be less intensive. Therefore, the shaking water bath is recommended to ensure the efficient extraction of the sample.

The manual shaking of the solutions in a specific time intervals (e.g. every 10 min) is also possible.

7.6 Extraction plastic tubes with screwing caps, resistance to temperature of 90 °C, of nominal capacity 25 ml to 50 ml.

To maintain the extraction ratio (sample portion/extraction solution) use the test tubes volume accordingly. Before use, check the cleanliness of tubes and caps.

7.7 Centrifuge, for minimum 4 000 min-1 (approx. 2 000 g).

7.8 Single use syringe filters (0,45 μm) or HPLC vials with filters, compatible with acidic solutions for filtering of test solutions prior to analysis.

7.9 High Pressure Liquid Chromatograph (HPLC).

7.10 Anion exchange chromatographic column, suitable for the selective separation of arsenate from other arsenic compounds present in the sample extracts.

It is highly recommended to use a guard column to prolong the lifetime of the analytical column.

Use of a different column and a different mobile phase is possible, providing the results are comparable. It is necessary and very important to verify optimal separation conditions. The other columns may be used in combination with the suitable type of mobile phase depending on the recommendations of the manufacturer (see 6.9).

7.11 Inductively coupled plasma mass spectrometer (ICP-MS).

7.12 Argon gas, purity ≥ 99,99 %.

Solid samples are milled using a laboratory grinder (7.2) according to EN 1482-2 and homogenized. Excessive heating during the sample pre-treatment should be avoided. Liquid samples are homogenized by thorough mixing before weighing the test portion.

Weigh a test portion of approximately 0,5 g to 1,0 g sample to the nearest milligram into an extraction tube (7.6) and add (20,00 ± 0,05) ml of the extraction solution (6.5) using a pipette or dispenser. The tubes shall be securely closed with a tight lid. Shake the tubes thoroughly in order to ensure that the samples are wetted sufficiently in the extraction solution (6.5) prior to placing them in the water bath in order to ensure a satisfactory extraction of the analyte.

The solutions are then placed into a heated shaking water bath (7.5) at 90 °C ± 2 °C and extracted for 60 min ± 5 min.

Include also a reagent blank sample. A blank test solution is prepared following the same procedure as for samples.

After extraction and cooling to room temperature the tubes are centrifuged for 10 min at 4 000 min-1 (approx. 2 000 g). The supernatant is transferred to clean plastic (PE or PP) tubes. Sample extracts should be filtered by a syringe filter (7.8) to clean HPLC vials prior to analysis. The sample extracts can be stored in a refrigerator (at approximately 4 °C) for a maximum of one week.

The external calibration is used for quantification. Prepare a blank calibration solution and at least three calibration standard solutions in the linear range of calibration for inorganic arsenic (As V) by diluting the arsenic standard solution II of As (V) concentration 1 mg/l (6.12) with extraction solution (6.5). Concentrations of calibration standards 0 μg/l, 25 μg/l, 50 μg/l and 100 μg/l are recommended. Transfer an aliquot of the calibration solutions to HPLC vials prior to analysis.

NOTE It is possible to calibrate the instrument for higher concentrations of the element if the calibration curve is linear.

The analytical procedure requires an adequate amount of experience in operating and optimizing the apparatus.

Due to differences between various kinds of HPLC and ICP-MS instruments, no detailed instructions can be given to operate the specific instrument. The instructions provided by the manufacturer should be followed.

Arsenic is a mono-isotopic element and can be evaluated at a mass/charge ratio (m/z) of 75 using ICP MS.

NOTE Instruments with single quadrupole ICP-MS can evaluate As at (m/z) 75 using He gas collision mode, H₂ gas reaction mode or no gas mode. It is possible to measure As in 0₂ cell gas reaction mode using triple quadrupole ICP-MS/MS instrumentation. As is shifted to its product ion AsO⁺ and is evaluated at (m/z) 91 in mass shift MS/MS mode.

It is advisable to allow the HPLC system (incl. the analytical column) to equilibrate and ensure stable conditions by turning on the HPLC flow of the mobile phase (see 6.9) prior to the start of the analysis. Repeated injections of a calibration blank can be necessary until stable chromatography is achieved and the analytical sequence can be started.

The software of the instrument is used to calibrate it and to calculate concentrations of the inorganic arsenic in the individual test solutions. All test solutions, blanks and calibration solutions are measured under the same optimized conditions. Example of the instrument conditions are given in Table 1.

HPLC conditions

Retention time for the analyte should be approximately twice the retention time corresponding to the void volume of the column, and the nearest peak in the chromatogram should be separated from the analyte peak by at least one full peak width at 10 % of the analyte peak height. It is recommended to verify sufficient separation of the analyte peak using a solution (6.13). Make sure that the HPLC run is long enough for chloride (m/z 35) and for any arsenic compounds with longer retention times than arsenate, to elute them from the column prior to the injection of the next sample. It is highly advisable to monitor isotope Cl (m/z 35) together with As (m/z 75). It should furthermore be ensured that the arsenate and chloride peaks do not co-elute in order to avoid interference from the polyatomic ion 40Ar35Cl+ in the mass spectrometer.

NOTE Using a triple quadrupole ICP-MS/MS instrumentation with oxygen O₂ reaction gas in mass shift mode (As at mass 75 → AsO⁺ at mass 91) is reliable tool how to overcome the polyatomic interference of ⁴⁰Ar³⁵Cl⁺ by measuring arsenic at (m/z) 91.

The quantitative oxidation of arsenite to arsenate in sample solutions should be verified (e.g. visual inspection of chromatogram by looking for an additional peak of arsenite As (III) or a reduced intensity of the arsenate As (V) peak). The solution for checking chromatographic separation (6.13), containing organic as well as inorganic arsenic forms (arsenite and arsenate) can be used for comparison with the chromatograms of the real samples.

The quantitative oxidation of arsenite can be also checked by spiking the sample with arsenite As (III), e.g. add a solution of arsenite 10 μg/l to the sample before the extraction procedure. After the extraction, measure the samples without the spike as well as with the spike of As (III) and evaluate the recovery at arsenate As (V) peak. Visual inspection of chromatogram by looking for an additional peak of arsenite As (III) is necessary. If the oxidation of As (III) to As (V) was quantitative, no As (III) peak should appear on the chromatogram.

If a satisfactory resolution between As (V) and Cl^- was not achieved, the chromatographic conditions should be optimized, e.g. by changing the mobile phase concentration or the mobile phase flow rate.

It is highly recommended to use a guard column to prolong the lifetime of the analytical column.

Calibration

The external calibration is used for the quantification of mass fraction of iAs (As V). Inject an appropriate volume of the calibration standards into an HPLC-ICP-MS system and calibrate the instrument e.g. determine the peak area of each of the calibration points to construct a calibration curve.

Samples measurement

Analyse a sequence of blank test solution, test samples and control samples (e.g. internal reference material) under the same conditions. Suitable dilution of the sample extracts with the mobile phase solution (6.9) is recommended for matrix suppression and to give a response within the linear calibration range. The recommended dilution of the samples is approximately 10 times, take 1 volume of the sample extract and add 9 volumes of the mobile phase solution (6.9), or 20 times, take 1 volume of the sample extract and add 19 volumes of the mobile phase solution (6.9). Test sample solutions, which still give a response outside the calibration range, should be diluted more times and appropriately with the mobile phase solution (6.9). If a significant blank value occurs, identify the source of this blank. If the blank is constant and not avoidable, it should be subtracted.

Check the instrument sensitivity e.g. by analysing one of the calibration standard solutions throughout the sequence (for example after each five or ten samples) and if necessary, use the results for recalibration of the system. As an analytical control, internal reference samples with known inorganic arsenic contents shall be analysed in all series of samples. The internal reference samples are to be subjected to all the steps in the method starting from water bath extraction.

If reference samples are not available, spike experiments should be performed to calculate the recovery of the method. It is advisable to check for memory effects, e.g. by the analysis of blank solutions after reference materials.

Examples of the chromatographic separation both for original sample as well as for the spiked sample are given in Annex A, Figures A.1 to A.4.

Table 1 — Example of possible settings of HPLC-ICP-MS instrumentation

The retention time of arsenate is identified from the analysis of the calibration solutions. The arsenate peak area in the standard calibration solutions, blank test solution and sample test solutions are determined.

Calculate the concentration of inorganic arsenic in the test sample solutions using the calibration function established by linear regression from the calibration curve. Calculate the content of inorganic arsenic (iAs) in organic and organo-mineral fertilizer, wX, as a mass fraction in mg/kg according to Formula (1).

The concentration of inorganic arsenic (iAs) in the blank test solution shall be as low as possible. If the inorganic arsenic concentration in the blank is constant and not avoidable, it should be subtracted from ρs.

(1)

where

(2)

where

Details of an inter-laboratory study on the precision of the method are summarized in Annex B. Repeatability and reproducibility were calculated according to and ISO 5725‑2 [10].

It is possible that the values derived from this study are not applicable to concentration ranges and matrices other than those given.

A detailed description of the materials is given in Annex B, Table B.1 (Samples selected for the inter-laboratory study).

The absolute difference between two independent single test results, obtained using the same method on identical test material in the same laboratory by the same operator using the same equipment within a short interval of time, will in no more than 5 % of the cases be greater than the repeatability limit r given in Table 1.

The absolute difference between two independent single test results, obtained using the same method on identical test material in different laboratories with different operators using different equipment, will in no more than 5 % of the cases be greater than the reproducibility limit R given in Table 2.

Table 2 — Mean values, repeatability and reproducibility limits

The test report shall contain at least the following information:

a) all information necessary for the complete identification of the sample;

b) the test method used with reference to this document including its year of publication;

c) the standard used (including its year of publication)

d) the test results obtained;

e) date of sampling and sampling procedure (if known);

f) date when the analysis was performed and finished;

g) whether the requirement of the repeatability limit has been fulfilled (optional);

h) all operating details not specified in this document, or regarded as optional, together with details of any deviations from the procedure, any incidents occurred or any unusual features observed when performing the method, which might have influenced the test result(s).

1. 
   (informative)
   
   Examples of typical chromatographic separation

Key

Figure A.1 — Original (natural) sample, organic fertilizer solid, iAs content is 0,28 mg/kg

Key

X	retention time (RT) (min)
Y	counts × 105
	75
	35
1	Inorganic As (V) (m/z 75)
2	Cl- (m/z 35)

Figure A.2 — Spiked sample (3 mg/kg iAs), organic fertilizer solid, checking of the Cl^- interferences

Key

Figure A.3 — Original (natural) sample, organo-mineral fertilizer solid, iAs content is 0,70 mg/kg

Key

X	retention time (min)
Y	counts × 105
	75
	35
1	inorganic As(V) (m/z 75)
2	Cl- (m/z 35)

Figure A.4 — Spiked sample (3 mg/kg iAs), organo-mineral fertilizer solid, checking of the Cl^- interferences

1. 
   (informative)
   
   Results of the inter-laboratory study
   1. Inter-laboratory study

The precision of the method has been determined in the year 2025 in an inter-laboratory study (ILS) with 9 participating laboratories from 8 EU countries and carried out on 6 different organic and organo-mineral samples.

The samples were chosen to represent all typical organic and organo-mineral fertilizers available on the market. The concentrations of arsenic in the samples were very low (usually below LOQ [limit of quantification]). Therefore, spiking procedure was necessary to achieve measurable concentrations of inorganic arsenic (iAs).

6 different sample materials (3 solids and 3 liquids, 2 of them fertilizing product blends) were included in the ILS.

The statistical results for the samples are given in Table B.1.

Table B.1 — Samples selected for the inter-laboratory study

• 1. Statistical results for determination of inorganic arsenic

Statistical evaluation was carried out based on the mathematical algorithms prescribed by ISO 5725-2 [10]. The ILS reflects the final statistical characteristics of the method for the determination of inorganic arsenic including both, the extraction and the measurement steps. The results are summarized in Table B.2.

Based on the statistical evaluation of the results from the inter-laboratory study, it is concluded that the proposed method is suitable for determination of inorganic arsenic after the extraction of the samples using mild acid oxidative mixture of HNO₃ and H₂O₂ following HPLC (or IC)-ICP-MS quantification in organic and organo-mineral fertilizers and fertilizing product blends containing them.

Table B.2 — Statistical results for determination of iAs in organic and organo-mineral fertilizers

Bibliography

[1] Regulation (EC) No 1009/2019 of the European Parliament and of the Council of 5 June 2019 laying down rules on the making available on the market of EU fertilising products and amending Regulations (EC) No 1069/2009 and (EC) No 1107/2009 and repealing Regulation (EC) No 2003/2003. Official Journal of the EU, L 170.

[2] EN 15517, Foodstuffs — Determination of trace elements — Determination of inorganic arsenic in seaweed by hydride generation atomic absorption spectrometry (HGAAS) after acid extraction

[3] EN 16278, Animal feeding stuffs — Determination of inorganic arsenic by hydride generation atomic absorption spectrometry (HG-AAS) after microwave extraction and separation by solid phase extraction (SPE)

[4] EN 16802, Foodstuffs — Determination of elements and their chemical species — Determination of inorganic arsenic in foodstuffs of marine and plant origin by anion-exchange HPLC-ICP-MS

[5] EN 17374, Animal feeding stuffs — Methods of sampling and analysis — Determination of inorganic arsenic in animal feed by anion-exchange HPLC-ICP-MS

[6] EN 17706, Plant biostimulants — Determination of inorganic arsenic

[7] SLOTH J.J., Report on collaborative trial, Animal feeding stuffs – Determination of inorganic arsenic in animal feed by HPLC-ICP-MS. National Food Institute DTU, Denmark, 2018

[8] prEN 17768, Organic and organo-mineral fertilizers —Digestion by aqua regia for subsequent determination of elements

[9] prEN 17770, Organic and organo-mineral fertilizers — Determination of the total content of specific elements by ICP-AES after digestion by aqua regia

[10] ISO 5725‑2, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method

[11] EN 1482‑1, Fertilizers, liming materials and inhibitors — Sampling and sample preparation — Part 1: General sampling provisions

[12] EN 1482‑3, Fertilizers, liming materials and inhibitors — Sampling and sample preparation — Part 3: Sampling of static heaps

1. Agilent^® is a registered trademark of Agilent Technologies Inc. This information is given for the convenience of users of this document and does not constitute an endorsement by CEN of the product named. ↑