EN 15479:2009
(Main)Fertilizers - Spectrophotometric determination of biuret in urea
Fertilizers - Spectrophotometric determination of biuret in urea
This European Standard specifies a method for the determination of biuret in urea. The method is applicable to urea and urea-based fertilizers.
Düngemittel - Spektrometrische Bestimmung von Biuret in Harnstoff
Diese Europäische Norm legt ein Verfahren zur Bestimmung von Biuret in Harnstoff fest.
Das Verfahren gilt für Harnstoff und für auf Harnstoff basierende Düngemittel.
Engrais - Détermination photométrique du biuret dans l'urée
La présente Norme européenne spécifie une méthode pour le dosage du biuret dans l’urée. La méthode
s’applique à l’urée et aux engrais à base d’urée.
Gnojila - Spektrofotometrijsko določevanje biureta v sečnini
General Information
- Status
- Published
- Publication Date
- 13-Jan-2009
- Technical Committee
- CEN/TC 260 - Fertilizers and liming materials
- Drafting Committee
- CEN/TC 260/WG 7 - Chemical analysis
- Current Stage
- 9093 - Decision to confirm - Review Enquiry
- Start Date
- 05-Feb-2025
- Completion Date
- 21-Jan-2026
Relations
- Effective Date
- 08-Jun-2022
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
Overview
EN 15479:2009 (CEN) specifies a standardized spectrophotometric method for the determination of biuret in urea and urea-based fertilizers. The method is based on formation of a violet cupric–biuret complex in an alkaline medium (with potassium sodium tartrate and CuSO4) and measurement of absorbance at about 546 nm. The standard covers reagents, apparatus, sampling/sample preparation references, calibration, procedure, calculation and precision.
Key topics and requirements
- Analytical principle: Biuret reacts with bivalent copper in alkaline tartrate to form a violet complex; absorbance measured at ~546 nm.
- Reagents (analytical grade): methanol, sulfuric acid (
0.05 mol/L), sodium hydroxide (0.1 mol/L), alkaline potassium sodium tartrate solution (recipe given), copper sulfate solution (15 g CuSO4·5H2O/L), freshly prepared biuret standard solution and methyl red indicator. - Apparatus: spectrometer/photometer with appropriate filters/cells, calibrated glassware (100, 250, 1 000 ml flasks; pipettes/burettes), cation-exchange column (strong cation resin, e.g. Duolite C20) for ammonia removal.
- Sampling & sample prep: sampling is outside the method (see EN 1482-1); sample preparation follows EN 1482-2. The procedure includes dissolution, filtration (or acid treatment to eliminate opalescence), cation-exchange treatment of aliquots when necessary, and temperature-controlled reaction (leave 15 min at 30 ± 2 °C).
- Calibration & measurement: construct a calibration curve using a series of biuret standard aliquots prepared and treated identically to samples; measure absorbance against the zero standard at ~546 nm.
- Calculation: mass concentration (biuret content) is calculated from the calibration graph and reported as percentage of sample (see equation (6) in EN 15479 for the exact formula using m = mass of biuret read from calibration in mg and V = aliquot volume in mL).
- Precision: inter-laboratory data (Annex A) give example performance:
- Urea sample mean 0.81% biuret: repeatability r = 0.04%, reproducibility R = 0.20%.
- Urea + S sample mean 0.76% biuret: r = 0.05%, R = 0.38%.
Applications and users
- Quality control laboratories in fertilizer production for routine monitoring of biuret in urea products.
- Regulatory and inspection bodies enforcing fertilizer composition requirements.
- Third-party testing laboratories involved in trade, certification and import/export verification.
- Research & development groups evaluating fertilizer formulations and impurity control.
Keywords: EN 15479, biuret determination, spectrophotometric determination, urea fertilizers, fertilizer analysis, CEN standard.
Related standards
- EN 1482-1 / EN 1482-2 - sampling and sample preparation for fertilizers (referenced for sampling and preparation).
- ISO 5725-1 - precision assessment (used for repeatability/reproducibility evaluation).
For laboratory implementation, follow EN 15479:2009 text for exact reagent recipes, procedural volumes, temperature controls and calculation details.
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Frequently Asked Questions
EN 15479:2009 is a standard published by the European Committee for Standardization (CEN). Its full title is "Fertilizers - Spectrophotometric determination of biuret in urea". This standard covers: This European Standard specifies a method for the determination of biuret in urea. The method is applicable to urea and urea-based fertilizers.
This European Standard specifies a method for the determination of biuret in urea. The method is applicable to urea and urea-based fertilizers.
EN 15479:2009 is classified under the following ICS (International Classification for Standards) categories: 65.080 - Fertilizers. The ICS classification helps identify the subject area and facilitates finding related standards.
EN 15479:2009 has the following relationships with other standards: It is inter standard links to CEN/TS 15479:2006, EN ISO 3696:1995, EN 1482-2:2024. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN 15479:2009 is associated with the following European legislation: Standardization Mandates: M/335. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
EN 15479:2009 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Düngemittel - Spektrometrische Bestimmung von Biuret in HarnstoffEngrais - Détermination photométrique du biuret dans l'uréeFertilizers - Spectrophotometric determination of biuret in urea65.080GnojilaFertilizersICS:Ta slovenski standard je istoveten z:EN 15479:2009SIST EN 15479:2009en,fr,de01-junij-2009SIST EN 15479:2009SLOVENSKI
STANDARDSIST-TS CEN/TS 15479:20061DGRPHãþD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 15479January 2009ICS 65.080Supersedes CEN/TS 15479:2006
English VersionFertilizers - Spectrophotometric determination of biuret in ureaEngrais - Détermination photométrique du biuret dansl'uréeDüngemittel - Spektrometrische Bestimmung von Biuret inHarnstoffThis European Standard was approved by CEN on 30 November 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN 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 translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, 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 STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2009 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 15479:2009: ESIST EN 15479:2009
Results of the inter-laboratory tests .9 Bibliography . 10
EN ISO 3696:1995, Water for analytical laboratory use — Specification and test methods (ISO 3696:1987) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 12944-1:1999 and EN 12944-2:1999 apply. 4 Principle In an alkaline medium in the presence of potassium sodium tartrate, biuret and bivalent copper form a violet cupric compound. The absorbance of the solution is measured at a wavelength of about 546 nm. 5 Reagents 5.1 General Use only reagents of recognized analytical grade and distilled or demineralized water, free from carbon dioxide and ammonia (grade 3 according to EN ISO 3696:1995). The quality of the water is particularly important in this determination. 5.2 Methanol 5.3 Sulfuric acid solution, c = approximately 0,05 mol/l. 5.4 Sodium hydroxide solution, c = approximately 0,1 mol/l. 5.5 Alkaline solution of potassium sodium tartrate In a graduated one-litre flask, dissolve 40 g of sodium hydroxide in 500 ml of water and leave to cool. Add 50 g of potassium sodium tartrate (NaKC4H4O6 4H2O). Make up to the mark and leave standing for 24 h before use. SIST EN 15479:2009
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