1、BRITISH STANDARDBS EN ISO11260:2011Soil quality Determination of effective cation exchange capacity and base saturation level using barium chloride solutionICS 13.080.10BS EN ISO 11260:2011This British Standard, having been prepared under the direction of the Health and Environment Sector Board, was
2、 published under the authority of the Standards Board and comes into effect on15 February 1995 BSI 2011ISBN 978 0 580 73146 4Amendments/corrigenda issued since publicationAmd. No. Date Comments9509 June 1997 Indicated by a sideline in the margin31 July 2011 This corrigendum renumbers BS 7755-3.3:199
3、5 as BS EN ISO 11260:2011This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard is the UK implementation ofEN ISO
4、 11260:2011. It is identical with ISO 11260:1994. It supersedes BS 7755-3.3:1995, which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee EH/4, Soil quality. A list of organizations represented on this committee canbe obtained on request to its secretary.Nati
5、onal forewordEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11260 June 2011ICS 13.080.10 English Version Soil quality - Determination of effective cation exchange capacity and base saturation level using barium chloride solution (ISO 11260:1994/Cor 1:1996) Qualit du sol - Dtermination de l
6、a capacit dchange cationique effective et du taux de saturation en bases changeables laide dune solution de chlorure de baryum (ISO 11260:1994/Cor 1:1996) Bodenbeschaffenheit - Bestimmung der effektiven Kationenaustauschkapazitt und der Basensttigung unter Verwendung von Bariumchloridlsung (ISO 1126
7、0:1994/Cor 1:1996) This European Standard was approved by CEN on 3 June 2011. 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 bibl
8、iographical 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, German). A version in any other language made by translation under the respon
9、sibility 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, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Gre
10、ece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Managem
11、ent Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 11260:2011: EForeword The text of ISO 11260:1994/Cor 1:1996 has been prepared by Technical Committee ISO/TC 190 “Soil quality” o
12、f the International Organization for Standardization (ISO) and has been taken over as EN ISO 11260:2011 by Technical Committee CEN/TC 345 “Characterization of soils” the secretariat of which is held by NEN. This European Standard shall be given the status of a national standard, either by publicatio
13、n of an identical text or by endorsement, at the latest by December 2011, and conflicting national standards shall be withdrawn at the latest by December 2011. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC sha
14、ll not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Den
15、mark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 11260:1994/Cor 1:1996 has
16、 been approved by CEN as a EN ISO 11260:2011 without any modification. iiBS EN ISO 11260:2011EN ISO 11260:2011 (E) BSI 2011 iiiContentsPageForeword ii1 Scope 12 Normative references 13 Principle 14 Procedures 15 Repeatability and reproducibility 46 Test report 4Annex A (informative) Results of inter
17、laboratory trials 6Annex B (informative) Bibliography 8Table A.1 Characteristics of soils used for theinterlaboratory trial for determination of CEC 6Table A.2 Results of the interlaboratory trial fordetermination of CEC 6Table A.3 Results of the interlaboratory trial fordetermination of the exchang
18、eable sodium content 7Table A.4 Results of the interlaboratory trial fordetermination of exchangeable potassium content 7Table A.5 Results of the interlaboratory trial fordetermination of exchangeable calcium content 7Table A.6 Results of the interlaboratory trial fordetermination of exchangeable ma
19、gnesium content 8List of references Inside back coverBS EN ISO 11260:2011EN ISO 11260:2011 (E)This page deliberately set blankBS EN ISO 11260:2011EN ISO 11260:2011 (E)11 ScopeThis International Standard specifies a method for the determination of the cation exchange capacity (CEC) at the pH of the s
20、oil and of the determination of the content of exchangeable sodium, potassium, calcium and magnesium in soil.This International Standard is applicable to all types of air-dried soil samples; pretreatment according to ISO11464 is recommended.NOTE 1The method described suffers from interference from c
21、alcium as calcite or gypsum in the sample. Also, the presence of any soluble salts gives values for the exchangeable cations that are higher than the actual exchangeable amounts 3, 4.NOTE 2Measurement of the specific electrical conductivity of the soil samples according to ISO11265 will indicate if
22、the soil samples are affected by salt.2 Normative referencesThe following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, an
23、d parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.ISO3696:1987, Water for analytical la
24、boratory use Specification and test methods. ISO11265:, Soil quality Determination of the specific electrical conductivity1). ISO11464:, Soil quality Pretreatment of samples for physico-chemical analyses1). 3 PrincipleThe determination of CEC as specified in this International Standard is a modifica
25、tion of the method proposed by Gillman 5. The CEC of soil samples is2) determined at the pH of the soil and at a low total ionic strength (about0,01 mol/l).The soil is first saturated with respect to barium by treating the soil three times with a0,1mol/l barium chloride solution. Thereafter, the soi
26、l is equilibrated with a0,01mol/l barium chloride solution. Subsequently, a known excess of0,02mol/l magnesium sulfate is added. All the barium present, in solution as well as adsorbed, is precipitated in the form of highly insoluble barium sulfate and, consequently, the sites with exchangeable ions
27、 are readily occupied by magnesium. The excess magnesium is determined by flame atomic absorption spectrometry (FAAS).It is also possible to determine the concentrations of sodium, potassium, calcium and magnesium (and other elements such as iron, manganese and aluminium) in the0,1ml/l barium chlori
28、de extract of the soil.If the barium chloride extract has a yellowish-brown colour, this indicates that some organic matter has been dissolved. If this occurs, record it in the test report.NOTE 3Since organic matter contributes to the CEC, its presence will result in a measured CEC value which is an
29、 underestimation of the actual CEC.NOTE 4Inductively coupled plasma atomic emission spectrometry (ICP-AES) may be used as an alternative method for the measurement of sodium, potassium, calcium and magnesium.NOTE 5The sum of exchangeable cations may give a result that is greater than the actual CEC
30、due to the dissolution of salts present in the soil. However, preliminary washing of the soil with water to remove these salts should not be employed because it will change the relative proportions of cations in the CEC.4 Procedures4.1 Leaching4.1.1 ReagentsUse only reagents of recognized analytical
31、 grade and water complying with grade2 of ISO3696.4.1.1.1 Barium chloride solution,c(BaCl2)=0,1mol/l.Dissolve24,43g of barium chloride dihydrate (BaCl2.2H2O) in water and make up to1000ml with water at20C.4.1.1.2 Barium chloride solution,c(BaCl2)=0,0025mol/l.Dilute25ml of the0,1ml/l barium chloride
32、solution to1000ml at20C.4.1.1.3 Magnesium sulfate solution,c(MgSO4)=0,0200mol/l.Dissolve4,93g 0,01g of magnesium sulfate heptahydrate (MgSO4.7H2O) (seenote6) in water and make up to1000ml at20C.NOTE 6MgSO4.7H2O may lose water of crystallization on standing. The reagent should be standardized by titr
33、ation with EDTA at pH10 using Eriochrome Black T indicator or be kept in a bottle in a sealed polyethylene bag placed in a refrigerator.1) To be published.2) See national foreword for details of textual errors.BS EN ISO 11260:2011EN ISO 11260:2011 (E) ISO 201124.1.2 Leaching procedureTransfer2,50g o
34、f air-dried soil (particlesizeu 2mm), for example, pretreated according to ISO11464, to a tightly stoppered polyethylene centrifuge tube of about50ml capacity. Note the combined mass of tube and soil (m1). Add30ml of barium chloride solution (4.1.1.1) to the soil and shake for1h. Balance the tubes a
35、nd centrifuge at3000g for10min.Transfer the supernatant liquid to a100ml volumetric flask. Repeat the addition of30ml of the barium chloride solution, the shaking and centrifugation twice more, adding the supernatant liquid to the100ml volumetric flask each time. Make up to the volume of the volumet
36、ric flask with barium chloride solution (4.1.1.1).Mix, filter and store the extract for the determination of the concentration of sodium, potassium, calcium and magnesium in accordance with4.3 and4.4. Add30ml of barium chloride solution (4.1.1.2) to the soil cake and shake overnight. (The barium con
37、centration in the equilibrium solution will be about0,01mol/l when2,5ml of solution is left in the soil cake.) Balance the tubes and centrifuge at about3000g for10min. Decant the supernatant liquid.Weigh the tube with its contents and cover (m2). Add30ml of magnesium sulfate solution (4.1.1.3) to th
38、e soil cake and shake overnight. Balance the tubes and centrifuge at3000g for10min. Decant the supernatant solution through a coarse filter paper(7cm diameter) into a conical flask and store for the determination of the concentration of excess of magnesium in accordance with4.2.4.Prepare a blank by
39、following the above described procedure completely without the addition of soil.4.2 Determination of CEC4.2.1 PrincipleTo prevent the formation of refractory compounds of magnesium with phosphate, aluminium, etc. in the flame, an acidified lanthanum solution is added to the solution obtained in acco
40、rdance with4.1.2, and magnesium is then determined by FAAS.4.2.2 ReagentsUse only reagents of recognized analytical grade and distilled or deionized water for all solutions.4.2.2.1 Hydrochloric acid, c(HCl)=12mol/l ( =1,19g/ml).4.2.2.2 Magnesium standard solution,c(Mg)=0,0010mol/l.Pipette50,0ml of t
41、he0,0200mol/l magnesium sulfate solution (4.1.1.3) into a volumetric flask of1000ml and make up to the mark with water.4.2.2.3 Acidified lanthanum solution,(La)=10mg/l.Dissolve15,6mg of lanthanum nitrate hexahydrate La(NO3)3.6H2O in water in a500ml volumetric flask, add42ml of hydrochloric acid (4.2
42、.2.1) and make up to the mark with water.4.2.3 Calibration seriesPipette0ml,1ml,2ml,3ml,4ml and5ml of magnesium standard solution (4.2.2.2) into a series of100ml volumetric flasks. Add10ml of acidified lanthanum solution (4.2.2.3), make each flask up to the mark with water and mix. These calibration
43、 solutions have magnesium concentrations of0mmol/l,0,01mmol/l,0,02mmol/l,0,03mmol/l,0,04mmol/l and0,05mmol/l, respectively.4.2.4 Spectrometric procedurePipette 0,200 ml of each of the final filtrates of the soil samples (see 4.1.2) and of the blanks (see 4.1.2 ) into individual 100 ml volumetric fla
44、sks. Add 10 ml of acidified lanthanum solution (4.2.2.3) to each flask, make up to the mark with water and mix.Determine the magnesium concentration in the diluted sample extracts ( ) , the diluted blank (cb ) and in the calibration solutions by FAAS at wavelength 285,2 nm, with the instrument set a
45、ccording to the manufacturers instructions for optimum performance.4.2.5 CalculationCorrect the concentrations of magnesium in the sample solutions for the volume of the liquid retained by the centrifuged soil after being treated with0,0025mol/l barium chloride solution using the formula:Calculate t
46、he cation exchange capacity (CEC) of the soil using the formula:CEC=(cb1 c2)3000/mwherec2 is the corrected magnesium concentration in the sample, in millimoles per litre;c1 is the magnesium concentration in the sample, in millimoles per litre;m1 is the mass of the centrifuge tube withair-dried soil,
47、 in grams;m2 is the mass of the centrifuge tube with wet soil, in grams.whereCEC is the cation exchange capacity of the soil, in centimoles positive charge per kilogram;c2 c1 30m2 m1+()30 -=1c 1BS EN ISO 11260:2011EN ISO 11260:2011 (E) ISO 20113If the CEC exceeds40cmol+/kg, repeat the determination
48、using less soil, adjusting the calculation accordingly.NOTE 7The unit “centimoles positive charge per a kilogram”, written in abbreviated form as cmol+/kg, is an absolute amount equivalent to the formerly used unit millielectrons per hundred grams.4.3 Determination of exchangeable sodium and potassi
49、um4.3.1 PrincipleSodium and potassium are measured by FAAS on an acidified0,1mol/l barium chloride extract of soil samples. A caesium solution is added to the test solution to eliminate ionization interference.4.3.2 ReagentsUse only reagents of recognized analytical grade and distilled or deionized water for all solutions.4.3.2.1 Acidified caesium chloride solution.Dissolve10g of caesium chloride in a small amount of water. Add83ml of hydrochloric acid (4.2.2.1) and make u
