SIST EN 15558:2009
(Main)Fertilizers - Determination of nitric and ammoniacal nitrogen according to Ulsch
General Information
- Abstract
This European Standard specifies a method for the determination of nitrate and ammoniacal nitrogen with reduction according to Ulsch.
The method is applicable to all nitrogenous fertilizers, including compound fertilizers, in which nitrogen is found exclusively in nitrate form, or in ammoniacal and nitrate form.
- Status
- Published
- Public Enquiry End Date
- 19-Oct-2008
- Publication Date
- 10-May-2009
- Technical Committee
- KAT - Soil quality
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 11-May-2009
- Due Date
- 16-Jul-2009
- Completion Date
- 11-May-2009
Overview
EN 15558:2009 - Fertilizers - Determination of nitric and ammoniacal nitrogen according to Ulsch - is a CEN (European) standard that specifies an analytical method for measuring nitrate (NO3‑N) and ammoniacal nitrogen (NH4‑N) in nitrogenous fertilizers. The method is applicable to fertilizers in which nitrogen occurs exclusively as nitrate or as a mixture of ammoniacal and nitrate forms. The procedure is commonly referred to as the Ulsch reduction–distillation method.
Key topics and technical requirements
- Analytical principle: Reduction of nitrate/nitrite to ammonia using metallic iron in an acidic medium, displacement of the liberated ammonia by excess sodium hydroxide, distillation of ammonia into a known volume of standard sulfuric acid, and back-titration of residual acid with standardized NaOH or KOH.
- Sample handling: Perform a solubility test and prepare samples according to EN 1482-2. Weigh sample aliquots (per guidance in the standard) and dilute appropriately before analysis.
- Reagents and purity: Use analytical-grade reagents and CO2‑/nitrogen‑free water (EN ISO 3696 grade 3). Key reagents include reduced powdered iron, sulfuric acid (standard and concentrated), carbonate-free NaOH/KOH titrant, and specific indicator solutions.
- Apparatus: Borosilicate glass distillation assembly (several recommended configurations), pipettes, graduated flasks, rotary shaker and receiving flasks for distillate collection. An automatic distillation apparatus may be used if statistically equivalent.
- Quality control: Include blank tests and a control test using sodium nitrate to verify method performance. Tabled guidance defines sample weights, dilutions and calculation factors for expressing results as % mass fraction N.
- Reporting: Test report must identify sample, reference EN 15558, state results as % mass fraction (nitrate or ammoniacal + nitrate N), sampling/analysis dates and any deviations.
Applications and users
- Fertilizer manufacturers - routine quality control and batch verification of nitrate and ammoniacal nitrogen content.
- Analytical laboratories - accredited labs performing fertilizer composition testing and compliance checks.
- Regulatory authorities - verification of product declarations and conformity with EU fertilizer regulations.
- Research and agronomy - studies on fertilizer formulations, nutrient release and product comparisons.
This standard is essential for anyone performing nitrogen analysis in fertilizers, ensuring consistent, comparable results across European laboratories.
Related standards and references
- EN 1482-1 / EN 1482-2 (sampling and sample preparation)
- EN 12944-1 / EN 12944-2 (vocabulary for fertilizers)
- EN ISO 3696 (water for analytical use)
- Regulation (EC) No 2003/2003 - Fertilisers (Annex IV, method 2.2.1)
Keywords: EN 15558:2009, Ulsch method, nitrate nitrogen determination, ammoniacal nitrogen, fertilizer testing, nitrogen analysis, CEN standard, fertilizer quality control.
Relations
- Effective Date
- 01-Jun-2009
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
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Frequently Asked Questions
SIST EN 15558:2009 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Fertilizers - Determination of nitric and ammoniacal nitrogen according to Ulsch". This standard covers: This European Standard specifies a method for the determination of nitrate and ammoniacal nitrogen with reduction according to Ulsch. The method is applicable to all nitrogenous fertilizers, including compound fertilizers, in which nitrogen is found exclusively in nitrate form, or in ammoniacal and nitrate form.
This European Standard specifies a method for the determination of nitrate and ammoniacal nitrogen with reduction according to Ulsch. The method is applicable to all nitrogenous fertilizers, including compound fertilizers, in which nitrogen is found exclusively in nitrate form, or in ammoniacal and nitrate form.
SIST EN 15558:2009 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.
SIST EN 15558:2009 has the following relationships with other standards: It is inter standard links to SIST-TS CEN/TS 15558:2008, SIST EN 12944-2:2002, SIST EN 12944-1:2002, SIST EN 1482-2:2025, SIST EN ISO 3696:1998. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST EN 15558:2009 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.
SIST EN 15558:2009 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.OVFKXDüngemittel - Bestimmung von Nitrat- und Ammoniumstickstoff nach UlschEngrais - Dosage de l'azote nitrique et ammoniacal selon UlschFertilizers - Determination of nitric and ammoniacal nitrogen according to Ulsch65.080GnojilaFertilizersICS:Ta slovenski standard je istoveten z:EN 15558:2009SIST EN 15558:2009en,fr,de01-junij-2009SIST EN 15558:2009SLOVENSKI
STANDARDSIST-TS CEN/TS 15558:20081DGRPHãþD
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 15558January 2009ICS 65.080Supersedes CEN/TS 15558:2007
English VersionFertilizers - Determination of nitric and ammoniacal nitrogenaccording to UlschEngrais - Dosage de l'azote nitrique et ammoniacal selonUlschDüngemittel - Bestimmung von Nitrat- undAmmoniumstickstoff nach UlschThis 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 15558:2009: ESIST EN 15558:2009
1 Scope This European Standard specifies a method for the determination of nitrate and ammoniacal nitrogen with reduction according to Ulsch. The method is applicable to all nitrogenous fertilizers, including compound fertilizers, in which nitrogen is found exclusively in nitrate form, or in ammoniacal and nitrate form. 2 Normative references The following referenced documents are indispensable for the application 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 1482-2, Fertilizers and liming materials — Sampling and sample preparation — Part 2: Sample preparation EN 12944-1:1999, Fertilizers and liming materials and soil improvers — Vocabulary— Part 1: General terms EN 12944-2:1999, Fertilizers and liming materials and soil improvers — Vocabulary— Part 2: Terms relating to fertilizers 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 Reduction of nitrates and nitrites to ammonia by means of metallic iron in an acid medium and displacement of the ammonia thus formed by the addition of an excess of sodium hydroxide: distillation of the ammonia and determination of the yield of ammonia in a known volume of standard sulfuric acid solution and titration of the excess sulfuric acid by means of a standard solution of sodium or potassium hydroxide. 5 Reagents 5.1 General Use only reagents of recognized analytical grade and distilled or demineralized water, free from carbon dioxide and all nitrogenous compounds (grade 3 according to EN ISO 3696:1995). 5.2 Diluted hydrochloric acid Mix one volume of concentrated hydrochloric acid solution, ρ(HCl) = 1,18 g/ml, with one volume of water. SIST EN 15558:2009
Key 1 round-bottomed, long-necked flask o
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