1、BRITISH STANDARD BS ISO 14869-2:2002 Soil quality Dissolution for the determination of total element content Part 2: Dissolution by alkaline fusion ICS 13.080.10 BS ISO 14869-2:2002 This British Standard, having been prepared under the direction of the Health and Environment Sector Policy and Strate
2、gy Committee, was published under the authority of the Standards Policy and Strategy Committee on 6 August 2002 BSI 6 August 2002 ISBN 0 580 40190 1 National foreword This British Standard reproduces verbatim ISO 14869-2:2002 and implements it as the UK national standard. The UK participation in its
3、 preparation was entrusted by Technical Committee EH/4, Soil quality, to Subcommittee EH/4/3, Chemical methods and soil characteristics, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British
4、 Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publi
5、cation does not purport to include all the necessary provisions of a contract. Users are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible internati
6、onal/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 the UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO titl
7、e page, pages ii and iii, a blank page, pages 1 to 3 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 CommentsINTERNATIONAL STANDARD ISO 14869-2 First edition 2002-08-01 Reference number
8、 ISO 14869-2:2002(E) Soil quality Dissolution for the determination of total element content Part 2: Dissolution by alkaline fusion Qualit du sol Mise en solution pour la dtermination des teneurs lmentaires totales Partie 2: Mise en solution par fusion alcalineBSISO148692:2002 ii BSISO148692:2002 ii
9、i Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a
10、 technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matte
11、rs of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard
12、 requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this part of ISO 14869 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Stand
13、ard ISO 14869-2 was prepared by Technical Committee ISO/TC 190, Soil quality, Subcommittee SC 3, Chemical methods and soil characteristics. ISO 14869 consists of the following parts, under the general title Soil quality Dissolution for the determination of total element content: Part 1: Dissolution
14、with hydrofluoric and perchloric acids Part 2: Dissolution by alkaline fusion BSISO148692:2002 1 Soil quality Dissolution for the determination of total element content Part 2: Dissolution by alkaline fusion 1 Scope This part of ISO 14869 specifies a method for the dissolution of total contents for
15、the following elements in soils: Na, K, Mg, Ca, Ti, Mn, Fe, Al, Si. This list is not exhaustive, and other elements are applicable for determination, provided they are not lost during the fusion process, where is the mass content of the element, expressed in milligrams per kilogram soil, is the dete
16、ction limit, in milligrams per litre, for the element and analytical method considered, 3 is a conventional factor, is the adjusted volume, in litres, of the final solution containing the dissolved sample, and is the mass of the test portion, in kilograms, the determination is not adversely affected
17、 by the high salt concentration in the resultant solution. The flux proposed in this method is suitable for a wide range of materials, among which soil samples are relatively easy to deal with. 2 Normative references The following normative documents contain provisions which, through reference in th
18、is text, constitute provisions of this part of ISO 14869. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this part of ISO 14869 are encouraged to investigate the possibility of applying the most recent
19、editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 3696:1987, Water for analytical laboratory use Specification and te
20、st methods ISO 11464:1994, Soil quality Pretreatment of samples for physico-chemical analyses ISO 11465:1993, Soil quality Determination of dry matter and water content on a mass basis Gravimetric method w(3dV /m) w d V m BSISO148692:2002 2 3P r i n c i p l e To avoid reduction of metallic oxides to
21、 metals, the dried and ground sample is first ignited at and afterwards fused with a mixture of dilithium tetraborate (one part) and lithium metaborate (four parts). While still liquid, the melt is poured quantitatively into dilute nitric acid. The suspension is then stirred until the solid phase di
22、ssolves completely. 4R e a g e n t s The reagents used shall meet the purity requirements of the subsequent analysis. 4.1 Water, complying with grade 2 of ISO 3696. 4.2 Dilithium tetraborate, Li 2 B 4 O 7 , apparent density when packed = 1. 4.3 Lithium metaborate, LiBO 2 , apparent density when pack
23、ed = 0,8. 4.4 Nitric acid, , . 4.5 Nitric acid, . Dilute of nitric acid (4.4) with water (4.1) to make of solution. 5 Apparatus 5.1 Grinding mill, capable of grinding dried soils without contamination by the elements of interest. 5.2 Drying oven and dessicator, for the determination of dry matter in
24、 accordance with ISO 11465. 5.3 Analytical balance, capable of weighing accurately to . 5.4 Furnace, which can reach a temperature of within . 5.5 Heating device, capable of heating the proposed flux above its melting point. Several devices are allowed: inductively heated furnace; muffle furnace; ai
25、r-propane Meker burner. 5.6 Crucible, of about capacity, preferably made of platinum:gold (95:5) alloy or vitreous carbon. Molten borates wet some metals and their alloys. For this reason, the use of the above type of crucible is strongly recommended. Failure to do so can result in loss of melt, and
26、 the possibility of carry-over between subsequent dissolutions. 5.7 Usual laboratory glassware, including beakers of capacity. 5.8 Magnetic stirrer, with polytetrafluoroethylene (PTFE)-coated follower. 6 Procedure Mill a representative portion of the dried sample, prepared in accordance with ISO 114
27、64, as fine as possible in order to obtain a subsample of approximately . Use a portion of that milled sample to determine the water content in accordance with ISO 11465. 450 C c(HNO 3 )= 15,2 mol/l = 1,41 g/ml c(HNO 3 )= 0,5 mol/l 32 ml 1 l 0,000 1 g 450 C 25 C1 h 30 ml 800 ml 20 g BSISO148692:2002
28、 3 Weigh precisely by means of the balance (5.3) about of the milled sample, and transfer to a crucible (5.6). Place the crucible in the furnace (5.4) and allow the temperature to reach progressively during . Maintain this temperature for . Allow the crucible to cool to room temperature. Weigh of di
29、lithium tetraborate (4.2) and of lithium metaborate (4.3), transfer to the crucible containing the ignited sample and mix thoroughly with a plastics spatula. Heat the mixture by means of the heating device (5.5) to between and until the boron salts melt and the sample dissolves completely. Depending
30、 on the type of heating device, dissolution is generally achieved within to . With unknown samples, it may be necessary to swirl the mixture at least once to verify that dissolution is complete. WARNING Handle the hot crucible with tongs while wearing protective gloves and eye/face protection. Befor
31、e the melt solidifies, carefully pour it quantitatively into a beaker (5.7) containing of dilute nitric acid (4.5). Stir the solution by means of a magnetic stirrer (5.8) until the solid phase is dissolved; generally to is sufficient. Transfer this solution to a volumetric flask of capacity , or dep
32、ending on the levels of concentration needed by the method of measurement for the elements of interest. Rinse the beaker with dilute acid (4.5), add these washings to the flask and adjust the volume to the mark still using acid (4.5). If this solution is turbid, discard it and perform a new fusion w
33、ith a smaller test portion. Using the same procedure without the sample, perform at least one blank test within each batch of fusions. Determinations should be undertaken within three days following the fusion. After a longer period of time, some compounds may hydrolyse or polymerize and precipitate
34、, rendering the solution unusable. If Pt-alloy or vitreous carbon crucibles (5.6) are not available, melt adhesion is likely to occur. In this case, the crucible plus adhering melt should be placed in the beaker with nitric acid and the solid melt allowed to dissolve. This can take several hours. Ca
35、re should be taken to ensure that the outside of the crucible is free of material containing elements of interest before it is immersed in the nitric acid, to avoid contamination of the sample solution. When the quantity of adhering melt is small enough, its dissolution can also be achieved by addin
36、g a few millilitres of nitric acid (4.5) to the crucible. In that case, slightly heating the solution on a hot plate may be necessary to assist dissolution. NOTE 1 Experience has shown that dissolution of sample can be considerably prolonged if the material is not ground below . NOTE 2 Very hot plat
37、inum alloy crucibles are best handled with platinum-tipped tongs to avoid problems of contamination from other metals. 7 Test report Submit the test report either separately or in conjunction with the test report of the subsequent analytical measurement. The test report shall contain the following i
38、nformation: a) a reference to this part of ISO 14869; b) complete identification of the sample; c) any details not specified in this part of ISO 14869, or which are optional, as well as any factor which may have affected the results. 0,200 g 450 C1 h 3h 0,200 g 0,002 g 0,800 g 0,005 g 1 000 C 1 100
39、C 10 min 30 min 200 ml 15 min 20 min 250 ml 500 ml 1 000 ml 200 ml 250 m BSISO148692:2002 BS ISO 14869-2:2002 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standa
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