BS EN 13366-2001 Fertilizers - Treatment with a cation exchange resin for the determination of the chelated micro-nutrient content and of the chelated fraction of micro-nutrients《肥.pdf

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1、BRITISH STANDARD BS EN 13366:2001 Fertilizers Treatment with a cation exchange resin for the determination of the chelated micro-nutrient content and of the chelated fraction of micro-nutrients The European Standard EN 13366:2001 has the status of a British Standard ICS 65.080 NO COPYING WITHOUT BSI

2、 PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN 13366:2001 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 Committee and comes into effect on 15 May 2001 BSI 05-2001 ISBN 0 5

3、80 37283 9 National foreword This British Standard is the official English language version of EN 13366:2001. The UK participation in its preparation was entrusted to Technical Committee CII/37, Fertilizers and related chemicals, which has the responsibility to: A list of organizations represented o

4、n 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 under the section entitled “International Standards Correspondence Inde

5、x”, 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 application. Compliance with a British Standard does not of itself co

6、nfer 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 related international and European developments and promulgate them in t

7、he 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. Amendments issued since publication Amd. No. Date CommentsEUROPEAN S

8、TANDARD NORME EUROPENNE EUROPISCHE NORM EN 13366 January 2001 ICS 65.080 English version Fertilizers Treatment with a cation exchange resin for the determination of the chelated micro-nutrient content and of the chelated fraction of micro-nutrients Engrais Traitement avec une rsine changeuse dions c

9、ationique pour la dtermination de la teneur en oligo- lments chlats et de la fraction chlate des oligo- lments Dngemittel Behandlung mit einem Kationenaustauscherharz zur Bestimmung des chelatisierten Spurennhrstoffgehaltes und des chelatgebundenen Anteils von Spurennhrstoffen This European Standard

10、 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 bibliographical references concerning such

11、 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 of a CEN member into its own language and

12、 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, Norway, Portugal, Spain, Sweden, Switzerlan

13、d 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 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN

14、13366:2001 EPage 2 EN 13366:2001 BSI 05-2001 Contents Foreword. 3 1 Scope . 3 2 Normative references . 4 3 Terms and definitions. 4 4 Principle . 4 5 Interferences 5 6 Apparatus 5 7 Reagents 5 8 Procedure 7 9 Expression of results . 9 10 Precision 9 11 Test report . 10 Bibliography . 11Page 3 EN 133

15、66:2001 BSI 05-2001 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 identical text or b

16、y endorsement, at the latest by July 2001, and conflicting national standards shall be withdrawn at the latest by July 2001. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belg

17、ium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.Page 4 EN 13366:2001 BSI 05-2001 1 Scope This standard defines a method for the treatment with a cation exchange resin

18、 for the determination of the chelated micro-nutrient content and the chelated fraction of the micro-nutrients (trace elements) cobalt, copper, iron, manganese, and zinc in fertilizers. This method applies to fertilizers containing one or more of the micro-nutrients cobalt, copper, iron, manganese,

19、and zinc, chelated by one or more chelating agents of the group of the polyamino polycarboxylic acids, previously determined according to EN 13368-1 and EN 13368-2, either alone or in combination with primary (N, P, K) and/or secondary (S, Na, Ca, Mg) nutrients. The limit of determination of the che

20、lated micro-nutrient content varies between 0,005 % in simple matrices with high amounts of chelated micro-nutrients, and 0,5 % in more complex cases (see 7.2). 2 Normative references This European standard incorporates by dated or undated reference, provisions from other publications. These normati

21、ve references are cited at the appropriate 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 refere

22、nces, the latest edition of the publication referred to applies (including amendments). EN 1482, Sampling of solid fertilizers and liming materials. EN 13368-1, Fertilizers Determination of chelating agents in fertilizers by ion chromatography Part 1:EDTA, HEDTA and DTPA. EN 13368-2, Fertilizers Det

23、ermination of chelation agents in fertilizers by ion chromatography Part 2:EDDHA and EDDHMA. EN ISO 3696, Water for analytical laboratory use Specification and test methods (ISO 3696:1987). 3 Terms and definitions For the purposes of this standard the following terms and definitions apply: 3.1 chela

24、ted fraction chelated content of a micro-nutrient, divided by its total content, and expressed as a percentage 4 Principle The sample is extracted with water and the extract adjusted to a neutral pH. The chelated forms of an element thus having a negative and/or neutral charge are not retained by an

25、 ion exchange resin of the strong sulfonated cationic type, and are separated from the non-chelated forms, having a cationic nature. The chelated forms are collected and their content determined by spectrometry, as well as the total element content.Page 5 EN 13366:2001 BSI 05-2001 5 Interferences An

26、y substance combining with a micro-nutrient to form a stable, negative or uncharged compound (chelate or complex) at neutral pH, will prevent the retention by the resin, and account for a certain degree of chelation. This is the case for many complexing agents, e.g. amino acids, citrate, and for che

27、lating agents other than ethylenediaminetetraacetic acid (EDTA), hydroxyethylethylenediaminetetraacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), ethylenediamine-di-(o-hydroxyphenyl)acetic acid (EDDHA) and ethylenediamine-di-(o-hydroxy-p-methylphenyl)acetic acid (EDDHMA). NOTE In orde

28、r to confirm the presence of the statutory chelating agents in the sample, EN 13368-1 and EN 13368-2 should be applied. In some cases, especially where complex fertilizer matrices with high amounts of phosphate are handled, or where micro-nutrients with a low chelated fraction are present, slow prec

29、ipitation reactions can occur during the contact with the resin, causing equilibrium shifts, adsorption, decreasing the exchange capacity and leading to inaccurate and imprecise results. It is advised to proceed as soon as possible with all steps. Highly unstable solutions cannot be considered. 6 Ap

30、paratus NOTE 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 contamination, especially by the elements Co, Cu, Fe, Mn and Zn. Usual laboratory equipment and in particular: 6.1 Sie

31、ve, sieve having a plastic body and a nylon mesh of aperture size less than the minimum diameter of the resin particles. The mass of the dry sieve shall be determined to within 0,01 g. 6.2 Tumbling shaker, tumbling or rotary shaker operating at a rotational speed between 30 min -1and 40 min -1 , at

32、a temperature of 18 C to 22 C. 6.3 Conductivity meter, equipped with a conductivity cell and a temperature controller. The cell shall be rinsed and dried before immersion, and calibrated with a 0,01 mol/l potassium chloride solution, having a specific conductivity at 20 C of 1,28 mS/cm. 6.4 Shaking

33、flasks, polyethylene flasks, each having a capacity of 50 ml and a stopper. 6.5 Membrane filters, micromembrane filters resistent to aqueous solutions, with porosity of 0,45 m. 7 Reagents 7.1 General a) all water used should conform to EN ISO 3696 and be degassed by boiling before use; b) all reagen

34、ts should be of recognized analytical grade.Page 6 EN 13366:2001 BSI 05-2001 7.2 Sulfonated cationic exchange resin 7.2.1 General Polystyrene divinylbenzene (PS-DVB) copolymer, slightly crosslinked (mass fraction of DVB less than or equal to 8 %), in sodic or protonic form, free from Co, Cu, Fe, Mn,

35、 and Zn 1) . 7.2.2 Preparation and determination of exchange capacity Protonate the resin prior to use, transform to the sodic form, to eliminate any contamination and measure the cationic exchange capacity (CEC) of the sodic resin in wet form as follows: Transfer 50 g of resin to a 500 ml beaker an

36、d add 250 ml of hydrochloric acid solution (7.4). Place on a magnetic stirrer. After 1 h of moderate stirring, the suspension is transferred onto the sieve (6.1). The resin is recovered and transferred back to the beaker. The acidification and separation operations are repeated as described. At the

37、end of the second operation, the protonated resin present on the sieve is washed thoroughly with water until the rinsing water is free from chloride when tested with silver nitrate. Transfer the wet protonated resin into a 500 ml beaker and add 250 ml of sodium chloride solution (7.5). While stirrin

38、g on a magnetic stirrer and using a pH meter, titrate the resin using the sodium hydroxide solution (7.6) until a stable pH of 7,0 is obtained. Let V obe the required volume of NaOH (7.6), in millilitres. Transfer quantitatively the resin that is now in sodic form onto the sieve (6.1). Rinse thoroug

39、hly with water until the rinsing water is free from chloride (silver nitrate test). Once rinsing is complete, allow the resin to drain. Weigh the drained wet resin to within 0,01 g. Let P be the mass in grams. The wet sodic resin can be stored in a stoppered opaque flask at ambient temperature for 2

40、 years. The cationic exchange capacity of the resin is given by the following formula: CEC = 2 V o/ P where: CEC is the cationic exchange capacity, in millimoles per gram of wet resin 7.3 Hydrochloric acid, c(HCl) 6 mol/l Hydrochloric acid, diluted 1 + 1 with water. 7.4 Hydrochloric acid solution, c

41、(HCl) = 1 mol/l Dilute 165 ml of hydrochloric acid solution (7.3) to 1 l.1)Dowex 50 x 4-400, Amberlite IR 120 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 endorsemen

42、t by CEN of these products.Page 7 EN 13366:2001 BSI 05-2001 7.5 Sodium chloride solution, c(NaCl) = 1 mol/l Dissolve 58,4 g of NaCl in water and dilute to 1 l. 7.6 Sodium hydroxide solution, c(NaOH) = 2 mol/l Carefully dissolve 80,0 g of NaOH in water and dilute to 1 l. 7.7 Sodium hydroxide solution

43、, c(NaOH) = 0,1 mol/l Dilute 25 ml of the sodium hydroxide solution (7.6) to 500 ml. 7.8 Nitric acid solution, c(HNO 3 ) = 0,1 mol/l Carefully dilute 6,9 ml of nitric acid (65 % HNO 3, = 1,40 g/ml) to 1 l. 7.9 Sodium hydroxide solution, c(NaOH) = 0,01 mol/l Dilute 50 ml of the sodium hydroxide solut

44、ion (7.7) to 500 ml. 7.10 Nitric acid solution, c(HNO 3 ) = 0,01 mol/l Dilute 50 ml of the nitric acid solution (7.8) to 500 ml. 8 Procedure 8.1 Preparation of the sample Prepare the sample according to EN 1482. NOTE 1 Sample may also be prepared according to method 1 (see 1 of bibliography). NOTE 2

45、 For the size reduction of samples with a high amount of chelating agents, it is not recommended to use a high speed laboratory mill. It is more convenient to grind the sample in a mortar to a particle size less than 1 mm. 8.2 Extraction of the sample Weigh an amount of sample, depending on the decl

46、ared content of water soluble micro-nutrient, to within 1 mg, into a volumetric flask of 250 ml or 500 ml, according to Table 1: Table 1 Sample mass/volume ratios Micro-nutrient content (%) 5 Mass of sample E (g) 10 5 2 Volume of the extract V (ml) 250 500 500 Add about 200 ml of water for a 250 ml

47、flask, or about 400 ml for a 500 ml flask. Stopper the flask, shake well to disperse the matter, and put on the tumbling shaker (6.2) for 30 min. Adjust to the mark with water, homogenize, and filter.Page 8 EN 13366:2001 BSI 05-2001 By means of a conductivity meter (6.3), measure the specific conduc

48、tivity at 20 C of the filtrate. This shall not exceed 1,5 mS/cm. Otherwise dilute the filtrate, in order to obtain a solution with a specific conductivity at 20 C not higher than 1,5 mS/cm. Let D be the dilution factor. NOTE 1 Aqueous sample extracts cannot be stabilized by acidifying since in acid

49、conditions, chelates can dissociate or precipitate, and the resin can be protonated. It is essential to proceed immediately with the analysis from the extraction (8.2) until the contact solution (8.4) has been obtained. NOTE 2 The maximum specific conductivity of 1,5 mS/cm corresponds to an ionic concentration of about 0,01 mol/l or less, depending on the intrinsic conductance of each ion present in the solution, and accounts for about a 10 fold excess of resin capacity,