EN 15749-2009 en Fertilizers - Determination of sulfates content using three different methods《肥料 使用三种不同方法对硫酸盐含量的测定》.pdf

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1、BS EN 15749:2009ICS 65.080NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDFertilizers Determination ofsulfates contentusing three differentmethodsThis British Standardwas published underthe authority of theStandards Policy andStrategy Committee on 30November 200

2、9 BSI 2009ISBN 978 0 580 66425 0Amendments/corrigenda issued since publicationDate CommentsBS EN 15749:2009National forewordThis British Standard is the UK implementation of EN 15749:2009. Itsupersedes DD CEN/TS 15749:2008 which is withdrawn.The UK participation in its preparation was entrusted to T

3、echnicalCommittee CII/37, Fertilisers and related chemicals.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compl

4、iance with a British Standard cannot confer immunityfrom legal obligations.BS EN 15749:2009EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15749 October 2009 ICS 65.080 Supersedes CEN/TS 15749:2008English Version Fertilizers - Determination of sulfates content using three different methods Engr

5、ais - 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 Regulations which stipulate the conditions for g

6、iving 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 European Standard exists in three official

7、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 national standards bodies of Austria, Bel

8、gium, 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 FO

9、R 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 15749:2009: EBS EN 15749:2009EN 15749:2009 (E

10、) 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 report . 18Annex A (info

11、rmative) Statistical results of the inter-laboratory tests . 19Bibliography . 22BS EN 15749:2009EN 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 held by DIN. This European St

12、andard 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 that some of the elements of th

13、is 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 Association. This document supersedes C

14、EN/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, Germany, Greece, Hungary, Iceland

15、, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 15749:2009EN 15749:2009 (E) 4 Introduction This document specifies three different methods for the determination of sul

16、fur. 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. BS EN 15749:2009EN 15749:2009 (E) 5 1 Scope This European

17、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 optical spectrometry (ICP-OES). Method C

18、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 edition of the referenced document (including

19、 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 im

20、provers - 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, Fertilizers Extraction of total calcium, total ma

21、gnesium, 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 methods (ISO 3696:1987) 3 Terms and definit

22、ions 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 15926, CEN/TS 15960 or CEN/TS 15961 and de

23、termined 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 measured by inductively coupled plasma-o

24、ptical emission spectrometry (ICP-OES). BS EN 15749:2009EN 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 sulfate concentration of the extract is meas

25、ured 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. Sample preparation shall be carried out in ac

26、cordance 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/ml with one volume of water. 6.1.2 Barium chl

27、oride 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 solution Pipette an aliquot part of one of th

28、e 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 the precipitate Bring the solution to the boi

29、l. 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. BS EN 15749:2009EN 15749:2009 (E) 7 Place the beaker, covered with a watch glass, in a boiling hot water bath (6.2.2) for 1 h. Then leave standing hot ( 60 C) unt

30、il 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 be checked by using a silver nitrate solution (6.1.

31、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). Allow to cool in a desiccator and weigh to 0,1 mg.

32、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= (1) Calculate the SO3content, wSO3, as mass frac

33、tion 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 volume, in ml. 7 Method B ICP-OES method 7.1 Reagent

34、s 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 Hydrochloric acid, approximately 1,18 g/ml; 7.1.2 Diluted

35、 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. Weigh to the nearest 0,1 mg, approximately 4,437

36、5 g of sodium sulfate (Na2SO4). Dissolve the weighted BS EN 15749:2009EN 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 months if stored at 4 C to 6 C. NOTE Sulfur stock solution

37、 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 accuracy of 0,1 mg. 7.2.2 Inductively coupled plasma Optic

38、al 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 shall be evacuated or be filled or continuously flushed

39、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 shown that the results are statistically equal to the r

40、esults 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 optimized according the manufacturers instructions. 7.3 Prep

41、aration 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 standard addition technique. This method allows the analysi

42、s 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 concentration between 10 mg/l and 150 mg/l of sulfur. 7.4.3 Pre

43、paration 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 20 %, 50 % and 100 % of the expected sulfur content. A

44、fter the additions, dilute each of the samples with the diluted hydrochloric acid (7.1.1). BS EN 15749:2009EN 15749:2009 (E) 9 A (external) calibration curve method can also be used instead of the standard addition method where the analytical results are demonstrated to be statistically equal. Appro

45、priate 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 conditions, and with the suitable background correction system in op

46、eration. 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.

47、4) in ascending order separately into the plasma, and measure the emission of sulfur. Perform at least two replicates and average the values if the values fall within an accepted range. After each measurement, aspirate water or diluted hydrochloric acid (7.1.2). The following special procedures can

48、be used to obtain high precision and accuracy necessary to analyse high sulfur contents in fertilizers: a) optimised instrument settings; b) simultaneous measurement of the signals of analyte and an appropriate internal standard element; c) adjustment of the matrix of calibration solutions to the sa

49、mple matrix; d) consistent identical treatment of samples and calibration solutions during preparation and measurement, or use gravimetric dilution instead of volumetric dilution; e) correction of instrumental drift and background (if required). Table 1 General analytical conditions for sulfur determination by ICP-OES Wavelength, nm 181,978 alternatives: 180,676 182,568 Background correction Yes Working range mg/l 1 to 150 Possible internal standard: Molybdenum 202,030 nm 281,615 nm 7