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1、BRITISH STANDARD BS EN 13650:2001 Soil improvers and growing media Extraction of aqua regia soluble elements The European Standard EN 13650:2001 has the status of a British Standard ICS 65.080 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Licensed Copy: sheffieldun sheffield
2、un, na, Mon Oct 30 01:39:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 13650:2001 This British Standard, having been prepared under the direction of the Consumer Products and Services Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy C
3、ommittee on 09 November 2001 BSI 09 November 2001 ISBN 0 580 38269 9 National foreword This British Standard is the official English language version of EN 13650:2001. The UK participation in its preparation was entrusted to Technical Committee AW/20, Top soil and other growing media, which has the
4、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 under the secti
5、on 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 application.
6、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 related internat
7、ional 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 17 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments i
8、ssued since publication Amd. No. DateComments Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 01:39:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13650 September 2001 ICS 65.080 English version Soil improvers and growing media - Extraction
9、of aqua regia soluble elements Amendements du sol et supports de culture - Extraction dlments solubles dans leau rgale Bodenverbesserungsmittel und Kultursubstrate - Extraktion von in Knigswasser lslichen Elementen This European Standard was approved by CEN on 11 August 2001. CEN members are bound t
10、o 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 national standards may be obtained on application to the Manag
11、ement 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 notified to the Management Centre has the same status as the o
12、fficial 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, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION CO
13、MIT 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 worldwide for CEN national Members. Ref. No. EN 13650:2001 E Licensed Copy: sheffieldun sheffieldun, na, Mon Oct
14、 30 01:39:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 13650:2001 (E) 2 Contents page Foreword .3 1Scope4 2Normative references4 3Terms and definitions.4 4Principle .4 5Reagents 5 6Apparatus.5 7Test sample passing through a 500 ? ?m sieve6 8Procedure.6 9Determination of extracted elements7 10Exp
15、ression of results7 11Precision 7 12Test Report.7 Annex A (informative) Results of an interlaboratory trial to determine aqua regia soluble elements.9 Annex B (informative) Methods of analysis used in the interlaboratory trial16 Bibliography17 Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 0
16、1:39:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 13650:2001 (E) 3 Foreword This European Standard has been prepared by Technical Committee CEN/TC 223 “Soil improvers and growing media“, the secretariat of which is held by BSI. This European Standard shall be given the status of a national stand
17、ard, either by publication of an identical text or by endorsement, at the latest by March 2002, and conflicting national standards shall be withdrawn at the latest by March 2002. The annexes A and B are informative. According to the CEN/CENELEC Internal Regulations, the national standards organizati
18、ons of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Licensed Copy: sheffieldun
19、 sheffieldun, na, Mon Oct 30 01:39:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 13650:2001 (E) 4 SAFETY PRECAUTIONS Care should be taken when handling samples that may contain sharps or are of a dusty nature. 1 Scope This European Standard specifies a method for the routine extraction of aqua re
20、gia soluble elements (as listed in annex B) from soil improvers or growing media. Materials containing more than about 28 % (m/m) organic matter will require treatment with additional nitric acid. With high solute concentrations in extract solutions, spectral interferences and background enhancement
21、 should be expected. The method is not applicable to liming materials and preformed materials such as mineral wool slabs and foam slabs. NOTE 1Aqua regia will not totally dissolve most soil improvers or growing media, and the efficiency of extraction for particular elements differs from element to e
22、lement. Such efficiency might also differ for the same element in different matrices. Elements extractable in aqua regia cannot therefore, be described as “Totals”; conversely they cannot be regarded as the “bio- available” fraction, as the extraction procedure is too vigorous to represent any biolo
23、gical process. NOTE 2 The requirements of the standard may differ from the national legal requirements for the declaration of the products concerned. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative referenc
24、es 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 references the la
25、test edition of the publication referred to applies (including amendments). EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696:1987). EN 13039, Soil improvers and growing media - Determination of organic matter content and ash. EN 13040:1999, Soil improvers a
26、nd growing media - Sample preparation for chemical and physical tests, determination of dry matter content, moisture content and laboratory compacted bulk density. 3 Terms and definitions For the purposes of this standard the terms and definitions given in EN 13039 and EN 13040 apply. 4 Principle Th
27、e dried sample is finely ground and extracted with a hydrochloric/nitric acid mixture by standing for 16 h at room temperature, followed by boiling under reflux for 2 h. The extract is clarified and the extracted elements determined. The test sample shall be ground to less than 500 ?m prior to aqua
28、regia digestion. Such grinding is designed to a) give a more homogeneous sample from which a sub-sample is taken; b) increase the efficiency of acid attack by increasing the surface area of the particles. Licensed Copy: sheffieldun sheffieldun, na, Mon Oct 30 01:39:36 GMT+00:00 2006, Uncontrolled Co
29、py, (c) BSI EN 13650:2001 (E) 5 5 Reagents 5.1 General All reagents used shall be of recognized analytical quality. Use water of grade 2 complying with EN ISO 3696. Deionized water may be used, providing that it meets the requirements given above. It is recommended that the same batch of water be us
30、ed throughout a given batch of determinations and that blank determinations are carried out. 5.2 Hydrochloric acid, c(HCl) = 12 mol/l; ? ? 1,18 g/ml; 37 % mass/volume. 5.3 Nitric acid, c(HNO3) = 15 mol/l; ? ? 1,42 g/ml; not less than 65 % mass/volume. 5.4 Nitric acid, c(HNO3) = 0,5 mol/l, 35 ml nitr
31、ic acid (5.3) is diluted to one litre of water. 6 Apparatus 6.1 General NOTEIt has been found convenient to keep separate sets of glassware including antibumping granules or roughened beads for the determinations given in annex B, in order to reduce the possibility of within-laboratory contamination
32、. Clean all new glassware by carefully immersing in warm nitric acid (5.4) for a minimum of 6 h and then rinse in water. The apparatus consists of the usual laboratory apparatus, and in particular the following : 6.2 Grinding mill, capable of grinding dried samples to a size less than 500 ?m without
33、 contamination by the elements to be determined. A mill causing little or no contamination is essential, as is adequate cleaning between samples to eliminate memory effects. Both agate and zirconium oxide mills have been found suitable. 5 6.3 Test sieve, of aperture size 500 ?m, e.g. test sieve with
34、 gauze preferably made from plastic materials, e.g. nylon. 6.4 Desiccator, of nominal volume 2 l. 6.5 Reaction vessel, of nominal volume of not less than 250 ml. NOTE 1It has been found convenient to use for mixing a two-neck Erlenmeyer type reaction vessel of nominal value 500 ml with ground-glass
35、joints and a drip funnel of nominal value 100 ml with conical ground-glass joints and stopper. NOTE 2A larger reaction vessel may be required for samples when a sample weight exceeding 1 g is taken for analyses or excessive frothing is experienced. 6.6 Reflux condenser, straight-through type, with c
36、onical ground-glass joints. NOTEWater-cooled condensers with a minimum effective length of at least 200 mm have been found suitable. The effective length is the internal surface, which is in contact with the cooling water. The overall external length of such condensers is usually at least 363 mm. 6.
37、7 Roughened glass beads, diameter 2 mm to 3 mm (or anti-bumping granules). 6.8 Temperature-controlled heating apparatus, capable of heating the contents of the reaction vessel to reflux temperature. 6.9 Funnel, of diameter approximately 100 mm. 6.10 Volumetric flask, of nominal capacity 100 ml. Lice
38、nsed Copy: sheffieldun sheffieldun, na, Mon Oct 30 01:39:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 13650:2001 (E) 6 6.11 Filter papers, cellulose-based ashless types, with a medium pore size of approximately 8 ?m and diameter of 150 mm. 6.12 Analytical balance, capable of weighing accurately
39、to 1,0 mg. 7 Test sample passing through a 500 ? ?m sieve Take approximately 5 g of the sample prepared in accordance with EN 13040:1999, clause 9, and grind the sub- sample using a mill (6.2) until all the sub sample has passed through the sieve (6.3). 8 Procedure 8.1 WARNING Digestions with hydroc
40、hloric and nitric acid are potentially hazardous and laboratory coats, gloves and safety spectacles or goggles shall be used. The digestion shall be carried out in a well-ventilated fume cupboard with the reflux digestion on a temperature - controlled heating apparatus. It is essential to add antibu
41、mping granules (or roughened glass beads) both to the blank and the samples to prevent bumping and loss of solution. It is important to maintain gentle reflux, both of the blank and the test samples, to avoid temperature fluctuations, which could cause local superheating. The toxicity or carcinogeni
42、city of each reagent used in this method has not been precisely defined; however, each chemical compound needs to be treated as a potential health hazard. From this viewpoint, reduce exposure to these chemicals to the lowest possible level by whatever means available. Toxic fumes are evolved by nitr
43、ic acid. Always use the concentrated acid in a fume cupboard. 8.2 Digestion Weigh approximately 1 g to 3 g, to the nearest 0,001 g, of the finely ground test sample (clause 7) into the reaction vessel (6.5). Moisten with about 0,5 ml to 1,0 ml water. Add while mixing, 21 ml of hydrochloric acid (5.2
44、) followed by 7 ml of nitric acid (5.3), drop by drop if necessary to reduce foaming. Allow to stand for 16 h at room temperature to allow for slow oxidation of the organic matter in the sample. NOTE 1It is common practice to add hydrochloric acid directly to the reaction vessel, followed by the nit
45、ric acid, and to assume that the aqua regia forms in the reaction vessel. However, problems have been encountered with materials rich in carbonates, where a substantial portion of the hydrochloric acid has been consumed before the nitric acid can be added. Under such circumstances, the correct forma
46、tion of aqua regia is doubtful. The amount of aqua regia is sufficient only for oxidation of about 0,85 g of organic matter. If there is any doubt about the amount of organic matter present, carry out a determination according to EN 13039. If there is more than 0,85 g of organic matter (correspondin
47、g to about 0,5 g of organic carbon) in the test sample reduce the quantity of sample analyzed or proceed as follows. Allow the first reaction with aqua regia to subside. Then add an extra 1 ml of nitric acid (5.3) only to every 0,17 g of organic matter above 0,85 g. Do not add more than 10 ml of nit
48、ric acid at any time, and allow any reaction to subside before proceeding further. Add a few roughened glass beads (6.7) and place the reaction vessel on a cool heating apparatus (6.8). Raise the temperature of the reaction mixture slowly until reflux conditions are reached and maintain for 2 h ensu
49、ring that the condensation zone is lower than 1/3 of the height of the condenser, then allow to cool. Transfer the contents of the reaction vessel to a 100 ml volumetric flask (6.10). Wash the reaction vessel at least three times with water decanting each washing into the volumetric flask before adding the next. Dilute to the mark with water and mix. Allow to stand so that most of any insoluble residue settles out of suspension. Decant the relatively sediment-free supernatant onto a filter paper (6.11), discarding at least the first 10 ml of filtrate. NOTE 2The
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