SIST EN 15604:2009
(Main)Fertilizers - Determination of different forms of nitrogen in the same sample, containing nitrogen as nitric, ammoniacal, urea and cyanamide nitrogen
Fertilizers - Determination of different forms of nitrogen in the same sample, containing nitrogen as nitric, ammoniacal, urea and cyanamide nitrogen
This European Standard specifies a method for the determination of any one form of nitrogen in the presence of any other form.
The method is applicable to any fertilizer provided for in Annex I of the Regulation (EC) No 2003/2003 [1] containing nitrogen in various forms.
Düngemittel - Bestimmung verschiedener, nebeneinander anwesender Stickstoff-Formen in derselben Probe mit Stickstoff in Form von Ammonium, Nitrat, Harnstoff und Cyanamid
Diese Europäische Norm legt ein Verfahren zur Bestimmung einer beliebigen Form von Stickstoff in Anwesenheit einer anderen Form von Stickstoff fest.
Das Verfahren ist auf alle Düngemittel anwendbar, die in Anhang I der Verordnung (EG) Nr. 2003/2003 [1] aufgeführt sind, und die Stickstoff in unterschiedlichen Formen enthalten.
Engrais - Détermination des différentes formes d'azote dans un même échantillon contenant l'azote sous forme nitrique, ammoniacale, uréique et cyanamidique
La présente Norme européenne définit une méthode de détermination d’une forme d’azote quelle qu’elle soit en présence d’une autre forme, quelle qu’elle soit.
La méthode s’applique à tout engrais indiqué dans l’Annexe 1 du Règlement (CE) N° 2003/2003 [1] contenant de l’azote sous différentes formes.
Gnojila - Določevanje različnih oblik dušika v istem vzorcu, ki vsebuje dušik v nitratni, amonijevi, sečninski in cianoamidni obliki
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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Düngemittel - Bestimmung verschiedener, nebeneinander anwesender Stickstoff-Formen in derselben Probe mit Stickstoff in Form von Ammonium, Nitrat, Harnstoff und CyanamidEngrais - Détermination des différentes formes d'azote dans un même échantillon contenant l'azote sous forme nitrique, ammoniacale, uréique et cyanamidiqueFertilizers - Determination of different forms of nitrogen in the same sample, containing nitrogen as nitric, ammoniacal, urea and cyanamide nitrogen65.080GnojilaFertilizersICS:Ta slovenski standard je istoveten z:EN 15604:2009SIST EN 15604:2009en,fr,de01-junij-2009SIST EN 15604:2009SLOVENSKI
STANDARDSIST-TS CEN/TS 15604:20081DGRPHãþD
SIST EN 15604:2009
EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN 15604January 2009ICS 65.080Supersedes CEN/TS 15604:2007
English VersionFertilizers - Determination of different forms of nitrogen in thesame sample, containing nitrogen as nitric, ammoniacal, ureaand cyanamide nitrogenEngrais - Détermination des différentes formes d'azotedans un même échantillon contenant l'azote sous formenitrique, ammoniacale, uréique et cyanamidiqueDüngemittel - Bestimmung verschiedener, nebeneinanderanwesender Stickstoff-Formen in derselben Probe mitStickstoff in Form von Ammonium, Nitrat, Harnstoff undCyanamidThis European Standard was approved by CEN on 6 December 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 15604:2009: ESIST EN 15604:2009
EN 15604:2009 (E) 2 Contents Page Foreword .3 1 Scope .4 2 Normative references .4 3 Terms and definitions .4 4 Principle .4 5 Reagents .6 6 Apparatus .8 7 Sampling and sample preparation . 13 8 Procedure . 14 9 Verification of the result . 21 10 Test report . 21 Bibliography . 22
SIST EN 15604:2009
EN 15604:2009 (E) 3 Foreword This document (EN 15604:2009) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by July 2009, and conflicting national standards shall be withdrawn at the latest by July 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. This document supersedes CEN/TS 15604:2007. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: 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 the United Kingdom.
SIST EN 15604:2009
EN 15604:2009 (E) 4 1 Scope This European Standard specifies a method for the determination of any one form of nitrogen in the presence of any other form. The method is applicable to any fertilizer provided for in Annex I of the Regulation (EC) No 2003/2003 [1] containing nitrogen in various forms. 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 15475, Fertilizers — Determination of ammoniacal nitrogen EN 15562, Fertilizers — Determination of cyanamide nitrogen 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 4.1 Total soluble and insoluble nitrogen According to the list of standard fertilizers given in Annex I of [1], this determination is applicable to products containing calcium cyanamide. In the absence of nitrates, the test sample is mineralized by direct Kjeldahl digestion. In the presence of nitrates, the test sample is mineralized by Kjeldahl digestion after reduction with the aid of metallic iron and stannous chloride. In both cases, the ammonia is determined according to EN 15475. NOTE If analysis shows an insoluble nitrogen content of more than 0,5 %, one concludes that the fertilizer contains other forms of insoluble nitrogen not included in the list in [1], Annex I. SIST EN 15604:2009
EN 15604:2009 (E) 5 4.2 Forms of soluble nitrogen 4.2.1 General The forms of soluble nitrogen referred to in 4.2.2 to 4.2.7 are determined from different aliquots taken from the same solution of the test sample: 4.2.2 Total soluble nitrogen 4.2.2.1 In the absence of nitrates, by direct Kjeldahl digestion. The ammonia is then determined (by the same method as that described in EN 15475). 4.2.2.2 In the presence of nitrates, by Kjeldahl digestion on an aliquot part taken from the solution after reduction according to Ulsch. The ammonia is then determined (by the same method as that described in EN 15475). 4.2.3 Total soluble nitrogen with the exception of nitrate nitrogen By Kjeldahl digestion after elimination in an acid medium of nitrate nitrogen with ferrous sulfate. The ammonia is then determined (by the same method as that described in EN 15475). 4.2.4 Nitrate nitrogen by difference 4.2.4.1 In the absence of calcium cyanamide, by determining the difference between the nitrogen determined as summarized in 4.2.2.2 and that determined as summarized in 4.2.3 or between total soluble nitrogen (4.2.2) and the sum of ammoniacal nitrogen and ureic organic nitrogen (4.2.5 + 4.2.6). 4.2.4.2 In the presence of calcium cyanamide, by determining the difference between the nitrogen determined as summarized in 4.2.2.2 and that determined as summarized in 4.2.3 or between the nitrogen determined as summarized in 4.2.2.2 and the sum of that determined as summarized in 4.2.5 + 4.2.6 + 4.2.7. 4.2.5 Ammoniacal nitrogen 4.2.5.1 Solely in the presence of ammoniacal nitrogen and ammoniacal plus nitrate nitrogen, according to EN 15475. 4.2.5.2 In the presence of urea nitrogen and/or cyanamide nitrogen by cold distillation after making slightly alkaline, the ammonia is absorbed in a standard solution of sulfuric acid and determined according to EN 15475. 4.2.6 Urea nitrogen 4.2.6.1 By conversion using urease, into ammonia which is titrated with a standard solution of hydrochloric acid. or 4.2.6.2 By gravimetry with xanthydrol: the co-precipitated biuret can be counted with urea nitrogen without great error, its content remaining generally low in absolute value in compound fertilizers. or 4.2.6.3 By difference according to Table 1. SIST EN 15604:2009
EN 15604:2009 (E) 6 Table 1 — Determination of urea nitrogen by difference Case Nitrate nitrogen Ammoniacal nitrogen Cyanamidic nitrogen Difference 1 2 3 4 Absent Present Absent Present Present Present Present Present Present Present Absent Absent (4.2.2.1) – (4.2.5.2 + 4.2.7) (4.2.3) – (4.2.5.2 + 4.2.7) (4.2.2.1) – (4.2.5.2) (4.2.3) – (4.2.5.2) 4.2.7 Cyanamide nitrogen By precipitation as a silver compound, the nitrogen being determined in the precipitate by the Kjeldahl method. 5 Reagents 5.1 General Use only reagents of recognized analytical grade and distilled or de-mineralized water of grade 3 according to EN ISO 3696:1995. 5.2 Potassium sulfate p.a. 5.3 Iron powder, reduced with hydrogen. The prescribed quantity of iron shall be able to reduce at least 50 mg of nitrate nitrogen. 5.4 Potassium thiocyanate, p.a. 5.5 Potassium nitrate, p.a. 5.6 Ammonium sulfate, p.a. 5.7 Urea, p.a. 5.8 Diluted sulfuric acid Dilute one volume of sulfuric acid (20 = 1,84 g/ml) in one volume of water. 5.9 Standard solution of sulfuric acid, c = 0,1 mol/l. 5.10 Sodium hydroxide solution, aqueous solution of about 30 % (mass concentration), free from ammonia. 5.11 Standard solution of sodium or potassium hydroxide, c = 0,2 mol/l, free from carbonates.
SIST EN 15604:2009
EN 15604:2009 (E) 7 5.12 Stannous chloride solution Dissolve 120 g of SnCl2 . 2H2O in 400 ml of concentrated hydrochloric acid (20 = 1,18 g/ml) and make up to 1 l with water. The solution shall be perfectly clear and prepared immediately before use. It is essential to check the reducing power of stannous chloride: dissolve 0,5 g of SnCl2 . 2H2O in 2 ml of concentrated hydrochloric acid (20 = 1,18 g/ml) and make up to 50 ml with water. Then add 5 g of Rochelle salt (potassium sodium tartrate), then a sufficient quantity of sodium bicarbonate for the solution to be alkaline to litmus paper. Titrate with an iodine solution (I2) of c = 0,05 mol/l in the presence of a starch solution as an indicator. 1 ml of iodine solution (I2) of c = 0,05 mol/l corresponds to 0,01128 g of SnCl2 . 2H2O. At least 80 % of the total tin present in the solution thus prepared shall be in bivalent form. For the titration at least 35 ml of the c = 0,05 mol/l iodine solution (I2) should be used. 5.13 Sulfuric acid, 20 = 1,84 g/ml. 5.14 Diluted hydrochloric acid Mix one volume of hydrochloric acid (20 = 1,18 g/ml) with one volume of water. 5.15 Acetic acid, 96 % to 100 %. 5.16 Sulfuric acid solution, containing about 30 % of H2SO4 (mass concentration). 5.17 Ferrous sulfate, crystalline, FeSO4 . 7H2O. 5.18 Standard sulfuric acid solution, c = 0,05 mol/l. 5.19 Octyl alcohol 5.20 Saturated solution of potassium carbonate 5.21 Standard solution of sodium or potassium hydroxide, c = 0,1 mol/l (free from carbonates). 5.22 Saturated solution of barium hydroxide 5.23 Sodium carbonate solution, at 10 % (mass concentration). 5.24 Hydrochloric acid, c = 2 mol/l. 5.25 Standard solution of hydrochloric acid, c = 0,1 mol/l. 5.26 Urease solution Suspend 0,5 g of active urease in 100 ml of water. Using hydrochloric acid 0,1 mol/l (5.25), adjust the pH to 5,4, measured by a pH-meter. SIST EN 15604:2009
EN 15604:2009 (E) 8 5.27 Xanthydrol Use a solution at 5 % in ethanol or methanol (5.32) (do not use products giving a high proportion of insoluble matter). The solution may be kept for three months in a well-stoppered bottle, away from the light. 5.28 Catalyst Use 0,3 g to 0,4 g of copper oxide per determination or an equivalent quantity of copper sulfate pentahydrate of 0,95 g to 1,25 g per determination. 5.29 Anti-bump granules, washed in hydrochloric acid and calcined. 5.30 Indicator solutions 5.30.1 Solution A Dissolve 1 g of methyl red in 37 ml of sodium hydroxide solution 0,1 mol/l and make up to 1 l with water. 5.30.2 Solution B Dissolve 1 g of methylene blue in water and make up to 1 l. 5.30.3 Combined indicator solution Mix one volume of solution A with two volumes of solution B. This indicator is violet in acid solution, grey in neutral solution and green in alkaline solution. Use 0,5 ml (10 drops) of this indicator solution. 5.30.4 Methyl red indicator solution Dissolve 0,1 g of methyl red in 50 ml of 95 % ethanol. Make up to 100 ml with water and filter if necessary. This indicator (four or five drops) may be used instead of that described in 5.30.3. 5.31 Indicator papers, Litmus bromothymol blue (or other papers sensitive to pH = 6 to pH = 8). 5.32 Ethanol or methanol, solution 95 %. 6 Apparatus 6.1 Distillation apparatus Consisting of a round-bottomed flask of suitable capacity connected to a condenser by means of a splash head. The equipment is made of borosilicate glass. NOTE The different types of equipment recommended for this determination are reproduced, showing all the features of construction, in Figures 1, 2, 3 and 4. An automatic distillation apparatus may also be used, provided that the results are statistically equivalent. SIST EN 15604:2009
EN 15604:2009 (E) 9 Dimensions in millimetres
Key 1 round-bottomed, long-necked flask of 1 000 ml capacity 2 distillation tube with a splash head, connected to the condenser by means of a spherical joint (No 18) (the spherical joint for the connection to the condenser may be replaced by an appropriate rubber connection) 3 funnel with a polytetrafluoroethylene (PTFE) tap (6) for the addition of sodium hydroxide (the tap may likewise be replaced by a rubber connection with a clip) 4 six-bulb condenser with spherical joint (No 18) at the entrance, and joined at the issue to a glass extension tube by means of a small rubber connection (when the connection to the distillation tube is effected by means of a rubber tube, the spherical joint may be replaced by a suitable rubber bung) 5 500 ml flask in which the distillate is collected 6 PTFE tap a hole Figure 1 — Distillation apparatus 1 SIST EN 15604:2009
EN 15604:2009 (E) 10 Dimensions in millimetres
Key 1 round-bottomed, short-necked flask of 1 000 ml capacity with a spherical joint (No 35) 2 distillation tube with a splash head, equipped with a spherical joint (No 35) at the entrance and a spherical joint (No 18) at the issue, connected at the side to a funnel with a polytetrafluoroethylene (PTFE) tap (5) for the addition of sodium hydroxide 3 six-bulb condenser with a spherical joint (No 18) at the entrance and joined at the issue to a glass extension tube by means of a small rubber connection 4 500 ml flask in which the distillate is collected 5 PTFE tap a enlarged cross-section Figure 2 — Distillation apparatus 2 SIST EN 15604:2009
EN 15604:2009 (E) 11 Dimensions in millimetres
Key 1 round-bottomed, long-necked flask of 750 ml or 1 000 ml capacity with a bell mouth 2 distillation tube with a splash head and a spherical joint (No 18) at the issue 3 elbow tube with a spherical joint (No 18) at the entrance, and a drip cone (the connection to the distillation tube may be effected by means of a rubber tube instead of a spherical joint) 4 six-bulb condenser joined at the issue to a glass extension tube by means of a small rubber connection 5 500 ml flask in which the distillate is collected Figure 3 — Distillation apparatus 3 SIST EN 15604:2009
EN 15604:2009 (E) 12 Dimensions in millimetres
Key 1 round-bottomed, long-necked flask of 1 000 ml capacity with a bell mouth 2 distillation tube with a splash head and a spherical joint (No 18), at the issue, connected at the side to a funnel with a polytetrafluoroethylene (PTFE) tap (5) for the addition of sodium hydroxide (a suitable rubber bung may be used instead of the spherical joint; the tap may be replaced by a rubber connection with an appropriate clip) 3 six-bulb condenser with a spherical joint (No 18) at the entrance, joined at the issue, by a rubber connection, to a glass extension tube (when the connection to the distillation tube is effected by means of a rubber tube, the spherical joint may be replaced by a suitable rubber bung) 4 500 ml flask for the collection of the distillate 5 PTFE tap Figure 4 — Distillation apparatus 4 SIST EN 15604:2009
EN 15604:2009 (E) 13
6.2 Apparatus for the determination of ammoniacal nitrogen According to analytical technique (8.2.5.3). The apparatus is made up of a specially shaped receptacle with a ground glass neck, with a side neck, a connecting tube with a splash head and a perpendicular tube for the introduction of air. The tubes can be connected to the receptacle by means of a simple perforated rubber bung. It is important to give a suitable shape to the end of the tubes introducing air, since the bubbles of gas should be evenly distributed throughout the solutions contained in the receptacle and the absorber. The best arrangement consists of small mushroom-shaped pieces with an external diameter of 20 mm and six openings of 1 mm around the periphery. 6.3 Apparatus for the determination of urea nitrogen According to the urease technique (8.2.6.1). It consists of a 300 ml Erlenmeyer flask, with a separating funnel and a small absorber. 6.4 Rotary shaker, 35 to 40 revolutions per min. 6.5 pH meter 6.6 Oven, capable of being maintained at a temperature of 130 °C. 6.7 Glassware: a) pipettes of 2 ml, 5 ml, 10 ml, 20 ml, 25 ml, 50 ml and 100 ml capacity; b) long-necked Kjeldahl flasks of 300 ml and 500 ml capacity; c) graduated flasks of 100 ml, 250 ml, 500 ml and 1 000 ml capacity; d) crucibles of sintered glass, pore diameter, 5 µm to 15 µm; e) mortars. 7 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 [2]. Sample preparation shall be carried out in accordance with EN 1482-2. SIST EN 15604:2009
EN 15604:2009 (E) 14 8 Procedure 8.1 Total soluble and insoluble nitrogen 8.1.1 In the absence of nitrates 8.1.1.1 Digestion Weigh, to an accuracy of 0,001 g, a quantity of the sample containing 100 mg of nitrogen at the most. Place it in the flask of the distillation apparatus (6.1). Add 10 g to 15 g of potassium sulfate (5.2), the catalyst (5.28), and a few anti-bump granules (5.29). Then add 50 ml of diluted sulfuric acid (5.8), and mix thoroughly. First heat gently, mixing from time to time, until foam no longer forms. Then heat in such a way that the liquid boils regularly and keep it boiling for 1 h after the solution has become clear, preventing any organic matter from sticking to the sides of the flask. Allow to cool. Carefully add about 350 ml of water, with mixing. Ensure that the dissolution is as complete as possible. Allow to cool and connect the flask to the distillation apparatus (6.1). 8.1.1.2 Distillation of ammonia Transfer with a precision pipette, into the receiver of the apparatus, 50 ml of a standard solution of sulfuric acid 0,1 mol/l (5.9). Add the indicator (5.30.3 or 5.30.4). Ensure that the tip of the condenser is at least 1 cm below the level of the solution. Taking the necessary precautions to avoid any loss of amm
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