1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 15962:2011Fertilizers Determination ofthe complexed micro-nutrientcontent and of the complexedfraction of micro-nutrientsBS EN 15962:2011 BRITISH STANDARDNational forewordT
2、his British Standard is the UK implementation of EN 15962:2011.The UK participation in its preparation was entrusted to TechnicalCommittee CII/37, Fertilisers and related chemicals.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does
3、not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. BSI 2011ISBN 978 0 580 67644 4ICS 65.080Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theSt
4、andards Policy and Strategy Committee on 31 January 2011.Amendments issued since publicationDate Text affectedBS EN 15962:2011EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 15962 January 2011 ICS 65.080 English Version Fertilizers - Determination of the complexed micro-nutrient content and of
5、the complexed fraction of micro-nutrients Engrais - Dosage de la teneur en oligo-lment complex et de la fraction complexe des oligo-lments Dngemittel - Bestimmung des Gehalts an komplexgebundenen Spurennhrstoffionen und der komplexgebundenen Fraktion von Spurennhrstoffen This European Standard was a
6、pproved by CEN on 3 December 2010. 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 nati
7、onal 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 langu
8、age and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latv
9、ia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brusse
10、ls 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 15962:2011: EBS EN 15962:2011EN 15962:2011 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Principle 44 Interferences 45 Apparatus .46 Reagents .57 Preparatio
11、n of the sample .58 Procedure .58.1 Preparation of the sample solution 58.2 Precipitation .68.3 Spectrometric determination 68.4 Water-soluble micro-nutrient content determination .69 Expression of results 79.1 Complexed micro-nutrient content in the fertilizer 79.2 Complexed fraction of a micro-nut
12、rient in the fertilizer.710 Precision .710.1 Inter-laboratory test .710.2 Repeatability .810.3 Reproducibility .811 Test report 8Annex A (informative) Results of the inter-laboratory test 10A.1 Test samples . 10A.2 Inter-laboratory test procedure . 10A.3 Results and statistical interpretation 10Bibl
13、iography . 14BS EN 15962:2011EN 15962:2011 (E) 3 Foreword This document (EN 15962:2011) 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
14、publication of an identical text or by endorsement, at the latest by July 2011, and conflicting national standards shall be withdrawn at the latest by July 2011. 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 s
15、hall 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. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
16、following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
17、Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 15962:2011EN 15962:2011 (E) 4 1 Scope This European Standard specifies a general method for the determination of the micronutrients complexed by complexing agents in fertilizers. The method allows the determination of the t
18、otal concentration of each complexed micronutrient in complexes after subtraction of the chelated micro-nutrients content, but it does not identify the individual complexing agents. This procedure concerns EC-fertilizers which contain complexed micro-nutrients covered by Regulation (EC) No 2003/2003
19、. The method is applicable to a mass fraction of the metal complexed of at least 0,07 %, 0,006 % and 0,035 % of Fe, Mn and Zn respectively (see 2). A lower limit of quantification has not been established for Cu and Co. 2 Normative references The following referenced documents are indispensable for
20、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
21、ISO 3696:1995, Water for analytical laboratory use Specification and test methods (ISO 3696:1987) 3 Principle The method is based on the precipitation of the inorganic forms at pH 9. Then the complexed forms of an element remain in solution and are separated from the non complexed forms. The complex
22、ed forms are collected and their content determined by spectrometry, as well as the soluble element content. NOTE For additional information see 2 and 3. 4 Interferences Any substance combining with a micro-nutrient to form a stable soluble compound (chelate or complex) at pH 9, will prevent the pre
23、cipitation of the metal, and account for a certain degree of complexation. This is the case for chelating agents. If the presence of chelates is suspected the appropriate analytical method should be used (see Bibliography) to identify and quantify the amount of element chelated, that should be subtr
24、acted from the amount of the element given by this method in order to obtain the actual amount of element complexed. 5 Apparatus All glassware, filters, and equipment parts coming in contact with samples and solutions, should be appropriate for micro-nutrient analysis, be very clean and free from co
25、ntamination, especially by the elements Co, Cu, Fe, Mn, and Zn. Usual laboratory equipment, glassware and in particular the following: 5.1 Magnetic stirrer. 5.2 Balance, capable for weighing to an accuracy of 1 mg. 5.3 pH-meter, equipped with a glass electrode; the system shall be calibrated with pH
26、 7 and pH 10 calibration buffers. 5.4 Membrane filters, micro-membrane filters resistant to aqueous solutions, with porosity of 0,45 m. BS EN 15962:2011EN 15962:2011 (E) 5 5.5 Cellulose filters, fast filtration quantitative cellulose filters. 6 Reagents All reagents shall be of recognized analytical
27、 grade. 6.1 Water used for the preparation of standard solutions. Water used for the preparation of standard solutions, and sample solutions shall conform to EN ISO 3696:1995, grade 1 and be free of organic contaminants. 6.2 Hydrogen peroxide, H2O2, 30 % to 33 %. 6.3 Sodium hydroxide solution, c(NaO
28、H) = 0,5 mol/l. Carefully dissolve 20,0 g of NaOH in water and dilute to 1 l. This solution is also available commercially. 6.4 Sodium hydroxide solution, c(NaOH) = 0,05 mol/l. Carefully dissolve 2,0 g of NaOH in water and dilute to 1 l. This solution is also available commercially. 6.5 Buffer solut
29、ion, pH = 7,0. 6.6 Buffer solution, pH = 10,0. 7 Preparation of the sample 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. NOTE For the size reduction of samples
30、with a high amount of complexing agents, it is not recommended to use a high speed laboratory mill. It is more convenient to grind the sample to a particle size less than 1 mm by the use of a mortar and pestle. 8 Procedure 8.1 Preparation of the sample solution Weigh, to the nearest 1 mg, a quantity
31、 of the fertilizer between 5 g and 10 g, depending on the declared content of the metal complex, into a 250 ml or 500 ml beaker. Add 200 ml or 400 ml of water. Stir using a magnetic stirrer (5.1) for 1 h. Transfer quantitatively into a 250 ml or 500 ml volumetric flask. Dilute to the mark with water
32、 and homogenize. The mass of the test sample and volume of extract should be taken according to Table 1. BS EN 15962:2011EN 15962:2011 (E) 6 Table 1 Preparation of sample solution Parameter Declared content of complexed micro-nutrient in the fertilizer 0,5 % 0,5 % Mass of test portion (g) 10 5 Mass
33、of element in the sample (mg) 50 25 Volume of the extract (ml) 250 500 Concentration of the element in the extract after precipitation (mg/l) 40 10 If insoluble matter is observed, filter immediately after the final volume has been reached using cellulose filters (5.5). 8.2 Precipitation Pipette 20
34、ml of the solution (8.1) into a 50 ml beaker. Add two drops of H2O2(6.2), stir and rise pH, with NaOH 0,5 mol/l (6.3) or 0,05 mol/l (6.4), to 9,0 as fast as possible in order to avoid reaction with atmospheric carbon dioxide. Cover the beaker. Rise pH again to 9,0 after 30 min and cover the beaker a
35、gain. Let the solution stand for a minimum of 18 h and a maximum of 24 h in the dark. Readjust the pH to 9,0, transfer the sample to a 100 ml volumetric flask and dilute to the mark with water (6.1). Filtrate the solution through the membrane filter (5.4). If precipitation is observed and filtration
36、 is difficult then samples may be centrifuged at 7 500 min-1at 20 C to 25 C for 10 min before filtration. The acidification of the solution required for the spectrometric determination (8.3) should be made as soon as possible after the precipitation process, in order to stabilize the solution. 8.3 S
37、pectrometric determination Determine the micro-nutrient concentration in the filtrate after precipitation procedure (8.2) by atomic absorption spectrometry (AAS) or by inductively coupled plasma emission spectrometry (ICP-ES). The AAS determination may be carried out in accordance with the appropria
38、te methods (see Regulation (EC) No 2003/2003). If flame AAS is used, removal of the organic compounds is required, and should be made in accordance with method 9.3 (1) using H2O2(6.2) and HCl 0,5 mol/l for the digestion of the samples and 0,5 % La as La(NO3)3, 0,2 % Cs as CsCl and 5 % HCl as matrix
39、modifier. Let d(i)be the micro-nutrient concentration of the filtrate, in milligrams per litre. 8.4 Water-soluble micro-nutrient content determination Extract following method 9.2 (1). The same sample solutions 8.1 may be used in some cases. Determine the water-soluble micro-nutrient content in the
40、sample by AAS or by ICP. The AAS determination may be carried out in accordance with the appropriate EC methods, referred to in 1. If flame AAS is used, removal of the organic compounds is required and should be made in accordance with method 9.3 (1) using H2O2(6.2) and HCl 0,5 mol/l for the digesti
41、on of the samples and 0,5 % La as La(NO3)3, 0,2 % Cs as CsCl and 5 % HCl as matrix modifier. Let S(i)be the water-soluble micro-nutrient content in the sample, expressed as mass fraction in percent. BS EN 15962:2011EN 15962:2011 (E) 7 9 Expression of results 9.1 Complexed micro-nutrient content in t
42、he fertilizer The content of a complexed micro-nutrient (i) in the fertilizer, C(i), expressed as mass fraction in percent, is given by the following equation: WVdC=0002(i)(i)(1) where d(i)is the micro-nutrient (i) concentration of the filtrate solution, in milligrams per litre; W is the mass of the
43、 test portion, in grams; V is the volume of the extract in millilitres. 9.2 Complexed fraction of a micro-nutrient in the fertilizer The complexed fraction F(i)of a micro-nutrient (i) is the ratio of the complexed micro-nutrient content C(i)to the water-soluble micro-nutrient content S(i)in the fert
44、ilizer, expressed as a percentage, and is given by the following equation: (i)(i)(i)100SCF = (2) where C(i)is the complexed micro-nutrient (i) content in percent (mass fraction); S(i)is the water-soluble micro-nutrient (i) content in percent (mass fraction). 10 Precision 10.1 Inter-laboratory test A
45、n inter-laboratory test has been carried out in 2008 with twelve participating laboratories and four different commercial samples. The results of this inter-laboratory test are summarized in Annex A. The results of one of the samples (LS-2) were not statistically analyzed because soluble element con
46、tent was very low and few laboratories were able to measure it. Repeatability and reproducibility were calculated according to ISO 5725-2. A second inter laboratory test was performed later in 2008 with ten participating laboratories and three different samples. In this test the method was modified,
47、 but it did not improve the reproducibility, so the modifications were ruled out. One of the samples was a non-commercial sample with less than 80 % complexed element and the repeatability and reproducibility results were poor. The values derived from this inter-laboratory test may not be applicable
48、 to concentration ranges and matrices other than those given in Annex A. BS EN 15962:2011EN 15962:2011 (E) 8 10.2 Repeatability The absolute difference between two independent test results obtained with the same method on identical test material, in the same laboratory, by the same operator, using t
49、he same equipment within a short interval of time, will in not more than 5 % of the cases exceed the values of r given in Table 2. 10.3 Reproducibility The absolute difference between two single test results obtained with the same method on identical test material, in different laboratories, by different operators, using different equipment, will in not more than 5 % of the cases exceed the values of R given in Table 2. Table 2 Mean values
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