1、February 2010DEUTSCHE NORM English price group 12No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 65.080!$C“1573259www.
2、din.deDDIN EN 15749Fertilizers Determination of sulfates content using three different methodsEnglish version of DIN EN 15749:2010-02Dngemittel Bestimmung von Sulfat mit drei verschiedenen VerfahrenEnglische Fassung DIN EN 15749:2010-02SupersedesDIN CEN/TS 15749:2008-10www.beuth.deDocument comprises
3、 pages24DIN EN 15749:2010-02 National foreword This standard has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials” (Secretariat: DIN, Germany) under the mandate M/335. The responsible German body involved in its preparation was the Normenausschuss Lebensmittel und la
4、ndwirtschaftliche Produkte (Food and Agricultural Products Standards Committee), Working Committee NA 057-03-02 AA Dngemittel. The DIN Standard corresponding to the International Standard referred to in this document is as follows: ISO 5725-1 DIN ISO 5725-1 Amendments This standard differs from DIN
5、CEN/TS 15749:2008-10 as follows: a) An introduction has been included explaining the status of the three test methods specified in this standard. b) In subclause 7.3 “Preparation of the extract”, reference is made to the Technical Specifications CEN/TS 15925, CEN/TS 15926, CEN/TS 15960 and CEN/TS 15
6、961, which contain the relevant methods specified in Regulation (EC) No 2003/2003 3, Annex IV, referred to in the previous edition. c) The standard has been brought in line with the current rules of presentation. Previous editions DIN CEN/TS 15749: 2008-10 National Annex NA (informative) Bibliograph
7、y DIN ISO 5725-1, Accuracy (trueness and precision) of measurement methods and results Part 1: General principles and definitions 2 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15749 October 2009 ICS 65.080 Supersedes CEN/TS 15749:2008English Version Fertilizers - Determination of sulfates c
8、ontent using three different methods Engrais - Dosage des sulfates selon trois mthodes diffrentes Dngemittel - Bestimmung von Sulfat mit drei verschiedenen Verfahren This European Standard was approved by CEN on 20 September 2009. CEN members are bound to comply with the CEN/CENELEC Internal Regulat
9、ions 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 Management Centre or to any CEN member. This Eu
10、ropean 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 Management Centre has the same status as the official versions. CEN members are the
11、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
12、and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1574
13、9:2009: EEN 15749:2009 (E) 2 Contents Page Foreword 3Introduction .41 Scope 52 Normative references 53 Terms and definitions .54 Principle 55 Sampling and sample preparation .66 Method A Gravimetric method 67 Method B ICP-OES method 78 Method C IC method 119 Precision of methods A, B and C 1710 Test
14、 report . 18Annex A (informative) Statistical results of the inter-laboratory tests . 19Bibliography . 22DIN EN 15749:2010-02 EN 15749:2009 (E) 3 Foreword This document (EN 15749:2009) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and liming materials”, the secretariat of which is
15、 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 April 2010, and conflicting national standards shall be withdrawn at the latest by April 2010. Attention is drawn to the possibility t
16、hat 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 has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Associati
17、on. This document supersedes CEN/TS 15749:2008. 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, Ger
18、many, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. DIN EN 15749:2010-02 EN 15749:2009 (E) 4 Introduction This document specifies three different m
19、ethods for the determination of sulfur. Based on the statistical results of the inter-laboratory tests, obtained with the same samples, the three methods produce equivalent results, and hence can be used all three methods on decision of the user and availability of equipment. DIN EN 15749:2010-02 EN
20、 15749:2009 (E) 5 1 Scope This European Standard specifies three different methods (Methods A, B and C) for the determination of sulfur present in fertilizers extracts in the form of sulfates. Method A specifies the gravimetric method. Method B specifies the method using inductively coupled plasma o
21、ptical spectrometry (ICP-OES). Method C specifies the method using ion chromatography (IC). 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 editi
22、on 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, Fert
23、ilizers and liming materials and soil improvers - Vocabulary - Part 2: Terms relating to fertilizers CEN/TS 15925, Fertilizers Extraction of total sulfur present in various forms CEN/TS 15926, Fertilizers Extraction of water soluble sulfur where the sulfur is in various forms CEN/TS 15960, Fertilize
24、rs Extraction of total calcium, total magnesium, total sodium and total sulfur in the forms of sulfates CEN/TS 15961, Fertilizers Extraction of water soluble calcium, magnesium, sodium and sulfur (in the forms of sulfates) EN ISO 3696, Water for analytical laboratory use - Specification and test met
25、hods (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 Method A: Gravimetric method Sulfur is extracted from the sample according to the methods described in CEN/TS 15925, CEN/TS 15
26、926, CEN/TS 15960 or CEN/TS 15961 and determined based on the gravimetric determination as barium sulfate. 4.2 Method B: ICP-OES Sulfur is extracted from the sample according to the methods described in CEN/TS 15925, CEN/TS 15926, CEN/TS 15960 or CEN/TS 15961 and its concentration in the extract is
27、measured by inductively coupled plasma-optical emission spectrometry (ICP-OES). DIN EN 15749:2010-02 EN 15749:2009 (E) 6 4.3 Method C: IC Sulfur is extracted from the fertilizer according to the methods described in CEN/TS 15925, CEN/TS 15926, CEN/TS 15960 or CEN/TS 15961 in the form of sulfate. The
28、 sulfate concentration of the extract is measured by ion chromatography (IC) equipped with a suppressor device and a conductivity detector. 5 Sampling and sample preparation Sampling is not part of the methods specified in this European Standard. A recommended sampling method is given in EN 1482-1.
29、Sample preparation shall be carried out in accordance with EN 1482-2. 6 Method A Gravimetric method 6.1 Reagents Use only reagents of recognized analytical grade and distilled or demineralized water (grade 3 according to EN ISO 3696). 6.1.1 Diluted hydrochloric acid Mix one volume of (HCl) = 1,18 g/
30、ml with one volume of water. 6.1.2 Barium chloride solution, (BaCl2.2 H2O) = 122 g/l. 6.1.3 Silver nitrate solution, = 5 g/l. 6.2 Apparatus 6.2.1 Porcelain crucibles 6.2.2 Hot water bath 6.2.3 Drying oven, set at 105 C 1 C. 6.2.4 Electric oven, set at 800 C 50 C. 6.3 Procedure 6.3.1 Sampling of the
31、solution Pipette an aliquot part of one of the extraction solutions containing between 20 mg and 100 mg of sulfur or 50 mg and 250 mg of SO3. Place this aliquot in a beaker of suitable capacity. Add 20 ml of diluted hydrochloric acid (6.1.1). Make up to about 300 ml with water. 6.3.2 Preparation of
32、the precipitate Bring the solution to the boil. Add, drop by drop, about 20 ml of the barium chloride solution (6.1.2) while stirring the solution vigorously. Boil for a few minutes. DIN EN 15749:2010-02 EN 15749:2009 (E) 7 Place the beaker, covered with a watch glass, in a boiling hot water bath (6
33、.2.2) for 1 h. Then leave standing hot ( 60 C) until the supernatant liquor is clear. Decant the clear solution through a slow filtration ash-free filter. Wash the precipitate several times with hot water. Continue to wash the precipitate on the filter until the filtrate is chloride free. This can b
34、e checked by using a silver nitrate solution (6.1.3). 6.3.3 Incineration and weighing of the precipitate Place the filter paper and precipitate in a porcelain crucible (6.2.1) previously weighed to the nearest 0,1 mg. Dry in the oven (6.2.3) and ash at approximately 800 C for half an hour (6.2.4). A
35、llow to cool in a desiccator and weigh to 0,1 mg. 6.4 Calculation and expression of the result 1 mg of barium sulfate corresponds to 0,137 mg of sulfur or to 0,343 mg of SO3. Calculate the sulfates content, wS, as mass fraction in percent of the fertilizer according to Equation (1): 2211S0,0137mvvmw
36、= (1) Calculate the SO3content, wSO3, as mass fraction in percent of the fertilizer according to Equation (2): 2,5SSO3= ww (2) where m1is the mass of the barium sulfate precipitate, in mg; m2is the mass of the test portion, in g; v1is the volume of the extraction solution, in ml; v2is the aliquot vo
37、lume, in ml. 7 Method B ICP-OES method 7.1 Reagents Use only reagents of recognized analytical grade, and water conforming to grade 2 of EN ISO 3696. Stock solutions shall be replaced after a maximum of one year, but the standard solution shall be freshly prepared monthly as a minimum. 7.1.1 Hydroch
38、loric acid, approximately 1,18 g/ml; 7.1.2 Diluted hydrochloric acid, mix 40 ml of hydrochloric acid (7.1.1) in 1 l of water; 7.1.3 Sulfur stock solution, corresponding to 1 000 mg/l sulfur. Dry in a pre-treatment step some grams of sodium sulfate (Na2SO4) at 105 C for 1 h. Let cool in a desiccator.
39、 Weigh to the nearest 0,1 mg, approximately 4,437 5 g of sodium sulfate (Na2SO4). Dissolve the weighted DIN EN 15749:2010-02 EN 15749:2009 (E) 8 mass in a small quantity of water in volumetric flasks of nominal capacity of 1 000 ml, fill to the mark with water. The solution is stable for several mon
40、ths if stored at 4 C to 6 C. NOTE Sulfur stock solution of 1 000 mg/l is also readily available commercially, and may be used instead. 7.2 Apparatus Common laboratory equipment and glassware, in particular equipment according to 7.2.1 to 7.2.2. 7.2.1 Analytical balance, capable of weighing to an acc
41、uracy of 0,1 mg. 7.2.2 Inductively coupled plasma Optical emission spectrometer Inductively Coupled Plasma Optical Emission Spectrometer (ICP-OES) with radial viewing of the plasma and simultaneous measurement of emission signals. For measuring sulfur at wavelengths below 190 nm the optical system s
42、hall be evacuated or be filled or continuously flushed with an inert gas as recommended by the instrument manufacturer to obtain high and stable signal intensities. The instrument shall be equipped with radial plasma as a minimum requirement; axial plasma is equally acceptable, as long as it can be
43、shown that the results are statistically equal to the results obtained with radial plasma. Background correction shall also be performed. Settings of the working conditions (e.g. viewing height, gas flows, RF or plasma power, sample uptake rate, integration time, number of replicates) shall be optim
44、ized according the manufacturers instructions. 7.3 Preparation of the extract The sulfur is extracted from the sample according to one of the methods described in CEN/TS 15925, CEN/TS 15926, CEN/TS 15960 or CEN/TS 15961. 7.4 Procedure 7.4.1 General Calibration shall be performed by means of the stan
45、dard addition technique. This method allows the analysis of fertilizers with unknown matrix composition or with a matrix that cannot be synthetically imitated easily. 7.4.2 Preparation of the test solution Dilute the extraction solution with the diluted hydrochloric acid (7.1.1) to obtain a concentr
46、ation between 10 mg/l and 150 mg/l of sulfur. 7.4.3 Preparation of the blank test solution Carry out a blank test at the same time as the extraction, with only the reagents. 7.4.4 Preparation of the calibration solutions The additions to the test solution, prior to the dilution step, should be about
47、 20 %, 50 % and 100 % of the expected sulfur content. After the additions, dilute each of the samples with the diluted hydrochloric acid (7.1.1). DIN EN 15749:2010-02 EN 15749:2009 (E) 9 A (external) calibration curve method can also be used instead of the standard addition method where the analytic
48、al results are demonstrated to be statistically equal. Appropriate matrix matching of the calibration solutions shall be performed if an (external) calibration method is used. 7.5 Determination 7.5.1 General Set up the instrument according to the manufacturers instructions using appropriate conditio
49、ns, and with the suitable background correction system in operation. For each instrument used, selectivity, limits of detection and quantification, precision, linear working area, and interference shall be established separately. 7.5.2 Determination by ICP-OES Aspirate the blank test solution (7.4.3), the test solution (7.4.2) and the various additions (7.4.4) in ascending order separately into the plasma, and measure the emission of sulfur. Perform at least two replicates an
