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1、BRITISH STANDARD BS EN 13368-1:2001 Fertilizers Determination of chelating agents in fertilizers by ion chromatography Part 1: EDTA, HEDTA and DTPA The European Standard EN 13368-1:2001 has the status of a British Standard ICS 65.080 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT
2、 LAW Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 01:39:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 13368-1:2001 This British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards C
3、ommittee and comes into effect on 15 May 2001 BSI 05-2001 ISBN 0 580 37284 7 National foreword This British Standard is the official English language version of EN 13368-1:2001. The UK participation in its preparation was entrusted to Technical Committee CII/37, Fertilizers and related chemicals, wh
4、ich has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue und
5、er the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct a
6、pplication. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor rela
7、ted international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 11 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued.
8、Amendments issued since publication Amd. No. DateComments Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 01:39:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13368-1 January 2001 ICS 65.080 English version Fertilizers - Determination of che
9、lating agents in fertilizers by ion chromatography - Part 1: EDTA, HEDTA and DTPA Engrais - Dtermination des agents chlatants dans les engrais par chromatographie ionique - Partie 1: EDTA, HEDTA et DTPA Dngemittel - Bestimmung von Chelatbildnern in Dngemitteln durch lonenchromatographie - Teil 1: ED
10、TA, HEDTA und DTPA This European Standard was approved by CEN on 1 January 2001. 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 b
11、ibliographical references concerning such national standards may be obtained on application to the 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
12、of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, No
13、rway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2001 CENAll rights of exploitation in any form and by any means reserved worldwid
14、e for CEN national Members. Ref. No. EN 13368-1:2001 E Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 01:39:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 2 EN 13368-1:2001 Contents Foreword3 1Scope 4 2Normative references 4 3Principle4 4Interferences.4 5Reagents.5 6Apparatus .6 7Prepara
15、tion of the sample.7 8Procedure .7 9Expression of results 7 10Precision.8 11Test report 8 Annex A (informative) Complete names of chelating agents 9 Annex B (informative) Chromatogram10 Bibliography11 Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 01:39:27 GMT+00:00 2006, Uncontrolled Copy,
16、(c) BSI Page 3 EN 13368-1:2001 Foreword This European Standard 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 identic
17、al text or by endorsement, at the latest by July 2001, and conflicting national standards shall be withdrawn at the latest by July 2001. EN 13368 consists of two parts dealing with the quantitative determination of chelating agents in fertilizers by ion chromatography: -Part 1 : EDTA, HEDTA and DTPA
18、 -Part 2 : EDDHA and EDDHMA The annexes A and B are informative. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Gree
19、ce, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 01:39:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 4 EN 13368-1:2001 1 Scope This method describes the procedure for
20、 the ion chromatographic determination of the total amount of each of the individual chelating agents EDTA, HEDTA, and DTPA in fertilizers containing one or more of these substances. The method allows the identification and the determination of the total water soluble fraction of each of these chela
21、ting agents. It does not allow to distinguish between the free form and the metal bound form of the chelating agents. NOTEEDTA, HEDTA and DTPA are abbreviations used in the standard for the sake of simplicity. For complete names see annex A. This method applies to fertilizers containing chelates of
22、one or more of the following micro-nutrients: cobalt, copper, iron, manganese, zinc and with a mass fraction of at least 0,1 %. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the ap
23、propriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the pub
24、lication referred to applies (including amendments). EN 1482, Sampling of solid fertilizers and liming materials. EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696 : 1987). 3 Principle The micro-nutrients associated with the chelating agents present in an aque
25、ous extract of the sample are replaced by iron (III). The iron chelates are separated and determined by ion chromatography. The separation is based on anion exchange, by elution with a nitrate acetate solution. The detection is based on UV photometry at 330 nm, after post-column reaction with dilute
26、 perchloric acid. 4 Interferences Several substances can interfere, to a degree largely dependent on the type of column used. With the column described in 6.2, the following phenomena have been observed. a)Injection of solutions having high concentrations of salts can cause shifts in the retention t
27、imes, mostly decreasing the retention when compared to the standard solutions. In these cases, the identity of the peaks can be confirmed by standard addition. b)Solutions having high concentrations of salts can also create a large signal at the void volume, poorly resolved from the HEDTA peak. c)Hi
28、gh concentrations of nitrate, carbonate, sulfate, and phosphate do not interfere. On the other hand, large amounts of chloride create a negative fronting peak poorly resolved from the DTPA peak, and altering its peak shape. d)Compounds, related to the group of polyamino polycarboxylic acids can inte
29、rfere. While signals for EDDHA, EDDHMA, and EDDHSA are not detected, relatively weak signals are observed for NTA and CDTA. Under some conditions NTA may coelute with HEDTA or EDTA. NOTEEDDHA, EDDHMA, EDDHSA, NTA and CDTA are abbreviations used in the standard for the sake of simplicity. For complet
30、e names see annex A. e)No signals have been detected for the following complexing agents : citrate, oxalate, tartrate, phthalate, and 20 naturally occuring amino acids. Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 01:39:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 5 EN 13368-1:2001 5
31、 Reagents 5.1 General a) all reagents should be of recognized analytical grade ; b) all water should conform to EN ISO 3696 and be degassed by boiling before use. 5.2 Nitric acid, c(HNO3) = 7,2 mol/l Nitric acid, diluted 1 + 1 with water. 5.3 Sodium hydroxide solution, c(NaOH) = 0,5 mol/l Dissolve 2
32、0 g of NaOH in pellet form in a 1 litre volumetric flask with water. Dilute to the mark and homogenize. 5.4 EDTA stock solution, c(EDTA) = 2 mmol/l Dissolve 372 mg of the disodium dihydrogen salt of ethylene diamine tetraacetic acid dihydrate in 400 ml of water in a 500 ml volumetric flask. After di
33、ssolution, dilute to the mark with water and homogenize. Store in a plastics bottle. 5.5 HEDTA stock solution, c(HEDTA) = 2 mmol/l Dissolve 380 mg of the trisodium salt of hydroxyethyl ethylene diamine triacetic acid dihydrate in 400 ml of water in a 500 ml volumetric flask. After dissolution, dilut
34、e to the mark with water and homogenize. Store in a plastics bottle. 5.6 DTPA stock solution, c(DTPA) = 2 mmol/l Dissolve 393 mg of diethylene triamine pentaacetic acid in 10 ml of NaOH (5.3) in a 50 ml beaker. After dissolution, transfer quantitatively into a 500 ml volumetric flask, dilute to the
35、mark with water and homogenize. Store in a plastic bottle. 5.7 EDTA/HEDTA/DTPA standard mixtures Into a set of 3 volumetric flasks of 100 ml, pipette respectively. 2,5 ml, 5 ml and 10 ml of each stock solution of 2 mmol/l (5.4, 5.5 and 5.6). Dilute to the mark with water and homogenize. These soluti
36、ons contain a mixture of EDTA, HEDTA and DTPA, in concentrations of respectively 0,05 mmol/l, 0,1 mmol/l and 0,2 mmol/l. They should be used within 2 days. 5.8 Eluent nitrate (50 mmol/l) and acetate (50 mmol/l) Dissolve 4,10 g of anhydrous sodium acetate (NaCH3COO) in a mixture of 800 ml of water an
37、d 6,95 ml of nitric acid (5.2) in a 1 litre volumetric flask. Dilute to the mark with water and homogenize. Adjust the pH of the eluent to 2,75 0,20. Before use, filter the solution through a 0,45 m membrane filter (6.3). NOTEThe concentration of the eluent influences the speed and the efficiency of
38、 the separation, which can be carried out with eluent concentrations varying between 25 mMol/l and 75 mMol/l of nitrate and acetate. At low concentrations, an improved separation between the void signal, the HEDTA and the EDTA peaks can be obtained, while at high concentrations a better DTPA peak sh
39、ape is observed. 5.9 Iron (III) nitrate solution Dissolve 5 g of ferric nitrate nonahydrate ( Fe(NO3)3.9H2O ) in a mixture of 800 ml of water and 21 ml of nitric acid (5.2) in a 1 litre volumetric flask. Dilute to the mark with water and homogenize. Store in a plastics bottle. NOTENitric acid is add
40、ed in order to stabilize the solution and to allow the complete replacement of other chelated micro- nutrients by iron (III). Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 01:39:27 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 6 EN 13368-1:2001 5.10 Perchloric acid solution, 2 % Dilute 29
41、 ml of perchloric acid (70 % HClO4 , ? = 1,67 g/ml) to 1 litre with water. 6 Apparatus Usual laboratory equipment, glassware, and : 6.1 Rotary shaker Rotary shaker capable of operating at a rotational speed of about 35 min-1 to 45 min-1. 6.2 Ion chromatograph Ion chromatograph equipped with : a) an
42、isocratic pump delivering the eluent (5.8) at a flow rate of 0,5 ml/min ; b) an injection valve with an injection loop of about 50 l ; c) an anion exchange separator column 10 m particles 2 % substrate x linking 100 meq capacity (per column) alkyl quaternary ammonium medium high (hydrophobicity)1) ;
43、 NOTE 1The column mentioned in c) is not exclusive. Any anion exchange column with comparable capacity, hydrophobicity, and selectivity can probably be used. NOTE 2Columns can, in their native state, exhibit some sensitivity towards various anions (e.g. nitrate, sulfate, phosphate) which can disappe
44、ar after treatment with excess iron. It can be necessary to precondition the column prior to its use by repeated injections, at least 10, of the iron (III) solution (5.9), followed by equilibration under eluent flow for at least 6 h. NOTE 3After many injections, especially of products having complex
45、 matrices, the column may lose some of its capacity and its separating efficiency. Substances like phenolic compounds (e.g. EDDHA, humic acids) can be strongly adsorbed on the column particles. Suspended and colloidal matter can block the column entrance and disturb the eluent flow. The column manuf
46、acturer cleaning instructions are consulted for the suitable cleaning procedure. NOTE 4The injection of undissolved matter severely decreases the lifetime of the column. Solutions should always be allowed to equilibrate, and then filter through a 0,2 m membrane filter before injection. d)a post-colu
47、mn reagent delivery module, delivering the reagent (5.10) at a flow rate between 0,5 ml/min and 0,6 ml/min ; NOTE 5The post-column reagent stabilizes the eluting ferric chelates and suppresses the signal of some possibly interfering substances. For the analysis of samples with simple matrices, the p
48、ost column reaction can be considered as superfluous. e)a UV/VIS detector with a 330 nm filter, output range set at an absorbance of 0,1 ; NOTE 6Ferric chelates of EDTA, HEDTA, and DTPA have a useful spectral absorbance between 250 nm and 350 nm. The absorbance at 254 nm offers a better sensitivity,
49、 but also produces a noisier background , more sensitive to interferences. f)an integrator. 6.3 Membrane filters Micromembrane filters resistent to aqueous solutions, with porosity of respectively 0,45 m and 0,2 m. 1) A combination of IonPac AS 7 separator and Ion Pac AG 7 guard column from Dionex Co, Sunnyvale, CA USA, or equivalent are examples of suitable products available commercially. This information is given for the convenience of users of this European Standard and does not constitute an endorsement by CEN of these products. Licensed Copy
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