SIST EN 16024:2011

• Abstract:

  This European Standard specifies a method for the determination of triazole (TZ) in urea or in fertilizers containing urea in the presence of dicyandiamide or methylpyrazole respectively using high-performance liquid chromatography (HPLC).

• Status: Published
• Public Enquiry End Date: 14-Mar-2010
• Publication Date: 15-May-2011
• ICS: 65.080 - Fertilizers
• Technical Committee: KAT - Soil quality
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 05-May-2011
• Due Date: 10-Jul-2011
• Completion Date: 16-May-2011
• Directive: 2003/2003 - Regulation (EC) N° 2003/2003 of the European Parlament and of the council of 13 October 2003 relating to fertilisers
• Mandate: M/335 - Standardization Mandate assigned to the CEN concerning the modernisation of the methods of anylysis of Fertilizers
• Ref Project: EN 16024:2011 - Fertilizers - Determination of 1H-1,2,4-triazole in urea and in fertilizers containing urea - Method using high-performance liquid chromatography (HPLC)

• Refers: SIST EN 12944-2:2002 - Fertilizers and liming materials and soil improvers - Vocabulary - Part 2: Terms relating to fertilizers
• Effective Date: 28-Jan-2026
• Refers: SIST EN 12944-1:2002 - Fertilizers and liming materials and soil improvers - Vocabulary - Part 1: General terms
• Effective Date: 28-Jan-2026
• Refers: SIST EN 1482-2:2025 - Fertilizers, liming materials and inhibitors - Sampling and sample preparation - Part 2: General sample preparation provisions
• Effective Date: 28-Jan-2026
• Refers: SIST EN ISO 3696:1998 - Water for analytical laboratory use - Specification and test methods (ISO 3696:1987)
• Effective Date: 28-Jan-2026
• Referred By: SIST-TS CEN/TS 17752:2023 - Inorganic fertilizers - Determination of specific inhibitors
• Effective Date: 28-Jan-2026

SIST EN 16024:2011 is the Slovenian adoption of EN 16024:2011, published by SIST and prepared by CEN. It specifies an HPLC method for determining triazole (TZ) in urea and in fertilizers containing urea, including matrices with dicyandiamide or methylpyrazole. It is a laboratory test method for fertilizer analysis, quality control, and product checking.

What does SIST EN 16024:2011 specify?

SIST EN 16024:2011 specifies how to determine triazole (TZ) in urea and in fertilizers containing urea by high-performance liquid chromatography (HPLC). The method is intended for analytical work where the fertilizer matrix may also contain dicyandiamide or methylpyrazole, so separation and detector selectivity matter in practice.

The document is organized into these main parts:

• Scope
• Normative references
• Terms and definitions
• Principle
• Reagents
• Apparatus
• Sampling and sample preparation
• Procedure
• Calculation and expression of the results
• Precision
• Test report
• Annex A with inter-laboratory statistics

Clause 7 makes clear that sampling itself is not part of the method, while sample preparation is. That means users need a suitable sampling approach before they apply the analytical procedure.

What are the key requirements of SIST EN 16024:2011?

SIST EN 16024:2011 gives a complete chromatographic method, from preparing the solution to reporting the result. The most important requirements are the sample handling, instrument conditions, calibration, and precision checks.

Sample preparation and solution making

Clause 8.1 prepares the test solution by dissolving about 0,2 g of sample in water, making up to 100 ml, then filtering through a 0,25 µm syringe filter. In practice, this means the lab must remove particles and conditioning agents before injection so they do not disturb the chromatogram.

Clause 7 directs users to sample preparation in EN 1482-2, and sampling is only recommended by EN 1482-1. This matters because the analytical result depends on getting a representative sample before the HPLC step starts.

Calibration and system check

Clause 8.2 uses a dilution series of triazole standard solutions to build the calibration curve. Clause 8.4 requires each calibration level to be injected three times, and the calibration curve may be used only when the correlation coefficient is above 0,99.

Clause 8.4 also includes a system check with a 1 mg/l triazole solution. The measured value must fall within ± 0,05 mg/l, which gives the user a practical check that the HPLC system is working before testing the sample.

HPLC conditions

Clause 8.3 sets the analytical conditions: reversed phase column, 20 °C column temperature, buffer solution and acetonitrile in an 85 + 15 mixture, 0,7 ml/min flow rate, and 10 µl injection volume. The detector is an electrochemical detector with a gold working electrode and an Ag+AgCl reference electrode.

These conditions matter because the method depends on consistent separation and detector response. The note to degas the eluent helps avoid bubbles and unstable detector signals.

Calculation and reporting

Clause 9 calculates the mass fraction of 1H-1,2,4-triazole from the peak area using the calibration curve, dilution factor, and sample mass. The result is the arithmetic mean of two values, reported to the nearest 0,001 %.

For the reader, this means the report is not based on a single injection alone. The method expects repeat measurements and a defined rounding rule.

Precision and test report

Clause 10 reports repeatability and reproducibility from an inter-laboratory test with eight laboratories and four fertilizer samples. That gives users a realistic idea of the spread they can expect between repeated tests and between laboratories.

Clause 11 lists what the test report must include, such as sample identification, method reference, results, sampling information if known, finish date, repeatability compliance, and any deviations or incidents. This is what a buyer, auditor, or quality manager will need when reviewing the result.

What terms does SIST EN 16024:2011 define?

SIST EN 16024:2011 relies on the vocabulary in EN 12944-1 and EN 12944-2 for its terms and definitions. The following terms are central to the method.

• Triazole (TZ) - The analyte measured by this method in urea and urea-containing fertilizers.
• 1H-1,2,4-triazole - The specific triazole compound named in the document title and used as the calibration standard.
• High-performance liquid chromatography (HPLC) - The separation technique used to measure triazole in solution.
• Reversed phase HPLC - The chromatographic mode used in the method, with a reversed phase column.
• Test solution - The prepared sample solution that is injected into the HPLC system.
• Calibration solution - A standard dilution used to build the calibration curve for quantification.
• Repeatability - The closeness of results under the same conditions in one laboratory.
• Reproducibility - The closeness of results between different laboratories.

Who uses SIST EN 16024:2011?

SIST EN 16024:2011 is used by fertilizer testing laboratories, manufacturer quality control labs, and third-party analytical service labs. It is also relevant for buyers and inspectors who need an agreed method for checking triazole content in urea-based fertilizers.

The method fits routine laboratory work where sample preparation, calibration, and chromatographic measurement must be documented. It is especially useful when the fertilizer contains dicyandiamide or methylpyrazole and the analyst needs a selective measurement.

Which standards are used with SIST EN 16024:2011?

SIST EN 16024:2011 cites several standards that support the method:

• EN 1482-2 - sample preparation for fertilizers and liming materials
• EN 12944-1 - general fertilizer vocabulary
• EN 12944-2 - fertilizer-specific vocabulary
• EN ISO 3696 - water quality for analytical laboratory use

It also points to related documents in its bibliography:

• EN 1482-1 - sampling
• EN 15360 - determination of dicyandiamide by HPLC
• EN 15905 - determination of 3-methylpyrazole by HPLC
• ISO 5725-1 and ISO 5725-2 - precision of measurement methods and results

These references show the method’s analytical context and the documents used for sampling, vocabulary, water quality, and precision evaluation.

What does the SIST EN 16024:2011 document contain?

SIST EN 16024:2011 contains a full laboratory method, not just a short definition of the analyte. It gives the working principle, reagent list, apparatus, preparation of test and calibration solutions, HPLC operating conditions, and the calculation approach.

The document also includes precision data from an inter-laboratory test and the associated repeatability and reproducibility limits. Annex A provides the statistical results of that test.

For practical use, the most useful contents are the calibration table, detector program, calculation formula, and test report checklist. Those parts tell the laboratory how to run the method, how to judge the system, and what to record after the analysis.

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Düngemittel - Bestimmung von 1H,2,4-Triazol in Harnstoff und in harnstoffhaltigen Düngemitteln - Verfahren mit Hochleistungs-Flüssigchromatographie (HPLC)Engrais - Dosage du 1H,2,4-triazole dans l'urée et les engrais contenant de l'urée - Méthode par chromatographie liquide à haute performance (HPLC)Fertilizers - Determination of 1H,2,4-triazole in urea and in fertilizers containing urea - Method using high-performance liquid chromatography (HPLC)65.080GnojilaFertilizersICS:Ta slovenski standard je istoveten z:EN 16024:2011SIST EN 16024:2011en,fr,de01-junij-2011SIST EN 16024:2011SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 16024
April 2011 ICS 65.080 English Version
Fertilizers - Determination of 1H-1,2,4-triazole in urea and in fertilizers containing urea - Method using high-performance liquid chromatography (HPLC)
Engrais - Dosage du 1H-1,2,4-triazole dans l'urée et les engrais contenant de l'urée - Méthode par chromatographie liquide à haute performance (HPLC)
Düngemittel - Bestimmung von 1H-1,2,4-Triazol in Harnstoff und harnstoffhaltigen Düngemitteln - Verfahren mit Hochleistungs-Flüssigchromatographie (HPLC) This European Standard was approved by CEN on 26 February 2011.
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. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
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B-1000 Brussels © 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 16024:2011: ESIST EN 16024:2011

Statistical results of the inter-laboratory test . 10Bibliography . 11 SIST EN 16024:2011

EN ISO 3696:1995, Water for analytical laboratory use — Specification and test methods (ISO 3696:198
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