EN 15959:2011

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Düngemittel - Bestimmung von Phosphor in den ExtraktenEngrais - Dosage du phosphore extraitFertilizers - Determination of extracted phosphorus65.080GnojilaFertilizersICS:Ta slovenski standard je istoveten z:EN 15959:2011SIST EN 15959:2012en,fr,de01-marec-2012SIST EN 15959:2012SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 15959
November 2011 ICS 65.080 Supersedes CEN/TS 15959:2009English Version
Fertilizers - Determination of extracted phosphorus
Engrais - Dosage du phosphore extrait
Düngemittel - Bestimmung von Phosphor in den ExtraktenThis European Standard was approved by CEN on 15 October 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.
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Statistical results of the inter-laboratory test . 10Bibliography . 12 SIST EN 15959:2012

The method is applicable to all extracts of fertilizers for the determination of the different forms of phosphorus as phosphorus soluble in mineral acids, water soluble phosphorus, phosphorus soluble in solutions of ammonium citrate, phosphorus soluble in 2 % citric acid and phosphorus soluble in 2 % formic acid. 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 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 After possible hydrolysis, phosphorus is precipitated in an acid media in the form of quinoline phosphomolybdate. After filtering and washing, the precipitate is dried at 250 °C and weighed. In the above mentioned conditions no interfering action is exerted by the compounds likely to be found in the solution (mineral and organic acids, ammonium ions, soluble silicates, etc.) if a reagent based on sodium molybdate or ammonium molybdate is used in the precipitation. 5 Sampling and sample preparation Sampling is not part of the method specified in this document. A recommended sampling method is given in EN 1482-1. Sample preparation shall be carried out in accordance with EN 1482-2. Grinding of the laboratory sample is recommended for homogeneity reasons. 6 Reagents 6.1 Water, distilled or demineralized. SIST EN 15959:2012

= 1,40 g/ml. 6.3 Preparation of reagents 6.3.1 Preparation of the reagent based on sodium molybdate Solution A: Dissolve 70 g of sodium molybdate dihydrate in 100 ml of distilled water. Solution B: Dissolve 60 g of citric acid monohydrate in 100 ml of distilled water and add 85 ml concentrated nitric acid (6.2). Solution C: Stir solution A into solution B to obtain solution C. Solution D: To 50 ml of distilled water, add 35 ml of concentrated nitric acid (6.2), then 5 ml of freshly distilled quinoline. Add this solution to solution C, mix thoroughly and leave standing overnight in the dark. After this make up to 500 ml with distilled water, mix again, and filter through a sintered glass funnel (7.7). 6.3.2 Preparation of the reagent based on ammonium molybdate Solution A: In 300 ml of distilled water, dissolve 100 g of ammonium molybdate while heating gently and stirring from time to time. Solution B: Dissolve 120 g of citric acid monohydrate in 200 ml of distilled water, add 170 ml of concentrated nitric acid (6.2). Solution C: Add 10 ml of freshly distilled quinoline to 70 ml of concentrated nitric acid (6.2). Solution D: Slowly pour, stirring well, solution
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