EN 13368-2-2012 en Fertilizers - Determination of chelating agents in fertilizers by chromatography - Part 2 Determination of Fe chelated by o o-EDDHA o o-EDDHMA and HBED by ion pa.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 13368-2:2012Fertilizers Determination of chelating agents in fertilizers by chromatographyPart 2: Determination of Fe chelated by o,o-EDDHA, o,o-EDDHMA and HBED by ion pair

2、 chromatographyBS EN 13368-2:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 13368-2:2012.It supersedes BS EN 13368-2:2007 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee CII/37, Fertilisers and related chemica

3、ls.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012. Published by BSI Stand

4、ardsLimited 2012ISBN 978 0 580 73762 6ICS 65.080Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 August 2012.Amendments issued since publicationDate Text affecte

5、dBS EN 13368-2:2012EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13368-2 August 2012 ICS 65.080 Supersedes EN 13368-2:2007English Version Fertilizers - Determination of chelating agents in fertilizers by chromatography - Part 2: Determination of Fe chelated by o,o-EDDHA, o,o-EDDHMA and HBED b

6、y ion pair chromatography Engrais - Dtermination des agents chlatants dans les engrais par chromatographie - Partie 2 : Dtermination du fer chlat o,o-EDDHA, o,o-EDDHMA et HBED par chromatographie dappariement dions Dngemittel - Bestimmung von Chelatbildnern in Dngemitteln mit Chromatographie - Teil

7、2: Bestimmung von Fe chelatisiertem o,o-EDDHA, o,o-EDDHMA und HBED mit lonen-Paarchromatographie This European Standard was approved by CEN on 6 July 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the s

8、tatus 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,

9、 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. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cr

10、oatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

11、 United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13368-2

12、:2012: EBS EN 13368-2:2012EN 13368-2:2012 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Terms and definitions .44 Principle 45 Interferences 56 Reagents .57 Apparatus .68 Sampling and sample preparation .79 Procedure .79.1 Preparation of the sample solution 79.2 Preparation of the

13、 calibration solutions 79.3 Chromatographic analysis 810 Expression of the results (Fe in Fe-chelates) 1310.1 Fe chelated by o,o EDDHA or o,o EDDHMA 1310.2 Fe chelated by HBED 1311 Precision 1311.1 Inter-laboratory test 1311.2 Repeatability 1411.3 Reproducibility 1412 Test report . 14Annex A (inform

14、ative) Statistical results of the inter-laboratory tests . 16A.1 Statistical results of the inter-laboratory test performed in 2003 16A.1.1 Test samples . 16A.1.2 Inter-laboratory test procedure . 16A.1.3 Results and statistical interpretation 16A.2 Results of the inter-laboratory test performed in

15、2010 . 17A.2.1 Test samples . 17A.2.2 Inter-laboratory test procedure . 17A.2.3 Results and statistical interpretation 18Annex B (informative) General procedure for the determination of the titrimetric purity of the chelating agents using a photometric automatic titrator . 19Annex C (informative) Co

16、mplete names of chelating agents 20Bibliography . 21BS EN 13368-2:2012EN 13368-2:2012 (E) 3 Foreword This document (EN 13368-2:2012) has been prepared by Technical Committee CEN/TC 260 “Fertilizers and lliming materials”, the secretariat of which is held by DIN. This European Standard shall be given

17、 the status of a national standard, either by publication of an identical text or by endorsement, at the latest by February 2013, and conflicting national standards shall be withdrawn at the latest by February 2013. Attention is drawn to the possibility that some of the elements of this document may

18、 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 EN 13368-2:2007. This document has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association.

19、 The following has been added to the former edition (EN 13368-2:2007) of this European Standard: a) new substance Fe-HBED added to the scope and to the title; b) requirements concerning the use of different columns in order to avoid overlapping of the meso isomer of Fe-o,o EDDHMA and Fe-HBED peaks a

20、dded in Clause 5, Interferences; c) iron-nitrate solution and Fe-HBED solution added in Clause 6, Reagents; d) the sampling method is not part of the standard; informative reference to EN 1482-1 added; e) Table 1 enlarged by a column for total chelate; f) typical chromatogram of a commercial Fe-HBED

21、 sample added (Figure 4); g) Formula (2) on calculation of Fe-HBED added; h) Table 2 enlarged by the precision data concerning determination of Fe-HBED; i) A.2: Results of the inter-laboratory test performed in 2010 added; j) Annex C: Complete names of chelating agents technical revised; k) Bibliogr

22、aphy revised. This European Standard “Fertilizers Determination of chelating agents in fertilizers by ion chromatography“ consists of the following parts: Part 1: Determination of EDTA, HEEDTA and DTPA by ion chromatography Part 2: Determination of Fe chelated by o,o-EDDHA, o,o-EDDHMA and HBED by io

23、n pair chromatography According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of

24、Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 13368-2:2012EN 13368-2:2012 (E) 4 1 Scope This European Sta

25、ndard specifies a method for the chromatographic determination of the iron chelated by each individual ortho(hydroxy)-ortho(hydroxy) isomer of the chelating agents o,o EDDHA, o,o EDDHMA and by HBED in fertilizers containing one or more of these substances, except for o,o EDDHMA and HBED mixes. The m

26、ethod allows the identification and the determination of the total concentration of water soluble iron chelates of these chelating agents. It does not determine the free form of the chelating agents. This method is applicable to EC fertilizers covered by Regulation (EC) No 2003/2003 4. It is applica

27、ble to a mass fraction of the metal chelated of at least 0,625 %. NOTE 1 The substances EDDHA (ethylenediamine-N,N-di(hydroxyphenyl)acetic acid and EDDHMA (ethylenediamine-N,N-di(hydroxymethylphenyl)acetic acid exist as several different isomeric forms. Positional isomers for the hydroxyl or methyl

28、groups (in ortho, meta, and para positions) as well as stereo isomers (meso and dl-racemic forms) are known. Both meso and dl-racemic forms of the ortho,ortho-EDDHA and ortho,ortho-EDDHMA are positional isomers for the hydroxyl groups allowed by the Regulation (EC) No 2003/2003. Since para, meta and

29、 ortho methyl positional isomers of the EDDHMA present quite similar stability, they could be grouped: in the method here described the para, meta and ortho methyl positional isomers of the o,o EDDHMA are considered together. HBED (N,N-bis(2-hydroxybenzyl)-ethylenediamine-N,N-diacetic acid) does not

30、 present isomeric forms. NOTE 2 At present, analytically pure standards only exist for ortho,ortho-EDDHA, ortho,ortho-EDDHMA and HBED. All other substances being unavailable as a standard, the influence of their eventual presence in the samples (with respect to the sensitivity and the selectivity of

31、 this method) has not been studied. NOTE 3 The meso and the dl-racemic forms of o,o EDDHA and o,o EDDHMA can be determined separately by this method. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its applica

32、tion. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12944-1:1999, Fertilizers and liming materials and soil improvers Vocabulary Part 1: General terms EN 12944-2:1999, Fertilizers and

33、 liming materials and soil improvers Vocabulary Part 2: Terms relating to fertilizers EN 1482-2, Fertilizers and liming materials Sampling and sample preparation Part 2: Sample preparation EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696) 3 Terms and definiti

34、ons For the purposes of this document, the terms and definitions given in EN 12944-1:1999 and EN 12944-2:1999 apply. 4 Principle The iron chelates are separated and determined by isocratic ion-pair high-performance liquid chromatography. When an iron chelate (anion) is added to a polar fluid (eluent

35、), containing a large cation, an ion pair is formed. This ion pair is retained by an apolar solid phase (stationary phase). The strength of the retention depends on the molecular size and its acidity. Then, each iron chelate presents a characteristic retention time depending on the chelating agent,

36、and it is separated from the other substances present in the sample. The separation is carried out on a reverse phase silica column and an aqueous solution of TBA+(tetrabutylammonium) and acetonitrile as eluent. The detection is based on photometry at 280 nm. NOTE For additional information, see 5,

37、6 and 7. BS EN 13368-2:2012EN 13368-2:2012 (E) 5 5 Interferences No interferences have been detected. Iron chelates with HBEP, EDDHSA, EDTA, DTPA, CDTA, HEEDTA, p,p-EDDHA, o,p-EDDHA, as well as the chelating agents do not interfere since they are separated from Fe-o,o EDDHA, Fe-o,o EDDHMA or Fe-HBED

38、. Fe-o,o EDDHA does not interfere with Fe-o,o EDDHMA or Fe-HBED. In the case that Fe-o,o EDDHMA and Fe-HBED are present in the same sample, an overlapping of the meso isomer of the Fe-o,o EDDHMA and Fe-HBED peaks may occur with some equipment depending on the column used. The use of a different colu

39、mn of the same type can solve this problem. NOTE For the complete names of the abbreviations of chelating agents used in this document, see Annex C. 6 Reagents 6.1 General All reagents shall be of recognised analytical grade. All water used for the preparation of eluents, standards, and sample solut

40、ions shall conform to EN ISO 3696, grade 1 and shall be degassed, and free of organic contaminants. If products with a declared purity of less than 99 % are used for the preparation of standard solutions, a correction should be made in order to obtain exactly the required concentration in the soluti

41、on. If there is any doubt of the purity of the standard, it is necessary to determine it. NOTE For this determination, a titrimetric method can be used. See Annex B for a general method using an automatic titrator. Manual titration could also be adequate. 6.2 Sodium hydroxide solution, c(NaOH) = 0,1

42、 mol/l. Dissolve 4 g of NaOH in pellet form in a 1 l volumetric flask with water (6.1). Dilute to the mark and homogenise. NOTE The incorporation of CO2from the atmosphere should be carefully avoided. Otherwise the dissolution of chelating agents (see 6.6, 6.7 and 6.8) can be incomplete. 6.3 Hydroch

43、loric acid solution, c(HCl) = 1,0 mol/l. Dilute 88 ml of hydrochloric acid (mass fraction 35 % HCl) to 1 000 ml with water. 6.4 Hydrochloric acid solution, c(HCl) = 0,1 mol/l. Dilute 50 ml of hydrochloric acid 1,0 mol/l (6.3) to 500 ml with water. 6.5 Iron-nitrate solution, (Fe) = 1 050 mg/l. Dissol

44、ve 0,759 4 g of ferric nitrate 9-hydrate (Fe(NO3)39H2O) in 100 ml of water. Check (for example by AAS) that the Fe concentration in this solution is 1 050 mg 30 mg/l. NOTE As the Fe(NO3)39H2O is deliquescent it will be added in solution of a known concentration. 6.6 Fe-o,o EDDHA solution, (Fe) = 100

45、 mg/l. Dissolve 0,322 1 g (see 6.1) of ethylenediamine-N,N-di(ortho-hydroxyphenyl)acetic acid in 350 ml of water and 27 ml of NaOH (6.2) in a 500 ml beaker. Add 50 ml of the Fe solution (6.5) to the chelating agent solution, stirring for about 5 min. BS EN 13368-2:2012EN 13368-2:2012 (E) 6 Adjust th

46、e solution to pH 7,0 with NaOH solution (6.2). Let the solution stand overnight in darkness to allow excess Fe to precipitate as oxide. Filter quantitatively through a cellulose filter and make up to volume (500 ml) in a volumetric flask with water. The standard obtained in this way can be stored in

47、 darkness for one year. 6.7 Fe-o,o EDDHMA solution, (Fe) = 100 mg/l. Dissolve 0,347 1 g (see 6.1) of ethylenediamine-N,N-di(ortho-hydroxy-para-methylphenyl)acetic acid the paramethyl isomer of o,o EDDHMA, (see Note 1 in Clause 1) in 350 ml of water and 27 ml of NaOH (6.2) in a 500 ml beaker. Add 50

48、ml of the Fe solution (6.5) to the chelating agent solution, stirring for about 5 min. Adjust the solution to pH 7,0 with NaOH solution (6.2). Let the solution stand overnight in darkness to allow excess Fe to precipitate as oxide. Filter quantitatively through a cellulose filter and make up to volu

49、me (500 ml) in a volumetric flask with water. The standard obtained in this way can be stored in darkness for one year. 6.8 Fe-HBED solution, (Fe) = 100 mg/l. Dissolve 0,347 1 g (see 6.1) of N,N-bis(2-hydroxybenzyl)-ethylenediamine-N,N-diacetic acid (HBED) or 0,379 7 g if HBEDHCI is used in 350 ml of water and 27 ml of NaOH (6.2) in a 500 ml beaker. Add 50 ml of the