DIN EN ISO 14254-2011 Soil quality - Determination of exchangeable acidity in barium chloride extracts (ISO 14254 2001) German version EN ISO 14254 2011《土质 氯化钡提取物中可互换酸度的测定(ISO 1425.pdf

1、September 2011 Translation by DIN-Sprachendienst.English price group 8No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).I

2、CS 13.080.10!$tJo“1813976www.din.deDDIN EN ISO 14254Soil quality Determination of exchangeable acidity in barium chloride extracts(ISO 14254:2001)English translation of DIN EN ISO 14254:2011-09Bodenbeschaffenheit Bestimmung der Austauschaciditt in Bariumchloridextrakten (ISO 14254:2001)Englische ber

3、setzung von DIN EN ISO 14254:2011-09Qualit du sol Dtermination de lacidit changeable dans un extrait au chlorure de baryum(ISO 14254:2001)Traduction anglaise de DIN EN ISO 14254:2011-09SupersedesDIN ISO 14254:2002-06www.beuth.deDocument comprises pagesIn case of doubt, the German-language original s

4、hall be considered authoritative.1008.11 DIN EN ISO 14254:2011-09 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee ISO/TC 190 “Soil quality” in collaboration with Technical Committee CEN/TC 345 “Characterization of soils” (Secretariat:

5、 NEN, Netherlands). The responsible German body involved in its preparation was the Normenausschuss Wasserwesen (Water Practice Standards Committee), Working Committee NA 119-01-02-02 UA Chemische und physikalische Verfahren. Expert assistance and specialized laboratories are recommended to perform

6、the sampling procedures described in this standard. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 3696 DIN ISO 3696 ISO 11265 DIN ISO 11265 ISO 11464 DIN 19747 ISO 11465 DIN ISO 11465 Amendments This standard differs from DIN ISO 1425

7、4:2002-06 as follows: a) the standard has been editorially revised. Previous editions DIN ISO 14254: 2002-06 National Annex NA (informative) Bibliography DIN 19747, Investigation of solids Pre-treatment, preparation and processing of samples for chemical, biological and physical investigations DIN I

8、SO 3696, Water for analytical laboratory use Specification and test methods DIN ISO 11265, Soil quality Determination of the specific electrical conductivity DIN ISO 11465, Soil quality Determination of dry matter and water content on a mass basis Gravimetric method EUROPEAN STANDARD NORME EUROPENNE

9、 EUROPISCHE NORM EN ISO 14254 June 2011 ICS 13.080.10 English Version Soil quality - Determination of exchangeable acidity in barium chloride extracts (ISO 14254:2001) Qualit du sol - Dtermination de lacidit changeable dans un extrait au chlorure de baryum (ISO 14254:2001) Bodenbeschaffenheit - Best

10、immung der Austauschaciditt in Bariumchloridextrakten (ISO 14254:2001) 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 standa

11、rd without any alteration. Up-to-date lists and bibliographical 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

12、 other language made by translation under the responsibility 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 Repub

13、lic, Denmark, Estonia, Finland, France, Germany, Greece, 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

14、NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management 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 14254:2011: EContents Page Foreword3 1 Scope 4 2 Normative references 4 3 Pr

15、inciple4 4 Reagents.5 5 Apparatus .6 6 Sample 7 7 Procedure .7 7.1 Total exchangeable acidity .7 7.2 Free H+acidity (optional) .7 7.3 Spectrometric determination of aluminium (optional) .7 8 Calculations7 9 Test report 8 DIN EN ISO 14254:2011-09 EN ISO 14254:2011 (E) 2 Foreword The text of ISO 14254

16、:2001 has been prepared by Technical Committee ISO/TC 190 “Soil quality” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 14254:2011 by Technical Committee CEN/TC 345 “Characterization of soils” the secretariat of which is held by NEN. This European Stand

17、ard shall be given the status of a national standard, either by publication 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

18、 this document may be the subject of patent rights. CEN and/or CENELEC shall 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

19、Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, 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 Un

20、ited Kingdom. Endorsement notice The text of ISO 14254:2001 has been approved by CEN as a EN ISO 14254:2011 without any modification. DIN EN ISO 14254:2011-09 EN ISO 14254:2011 (E) 3 1 ScopeThis International Standard specifies a method for the determination of exchangeable acidity in barium chlorid

21、eextracts of soil samples obtained according to ISO 11260.The procedure described herein mainly concerns the determination of total exchangeable acidity by means of afixed-pH end-point titration (see note). Two optional procedures are also given, describing respectively,determinations of free H+acid

22、ity and of aluminium in the extracts.This International Standard is applicable to all types of air-dry soil samples which have been pretreated inaccordance with ISO 11464.NOTE Titration of exchangeable acidity by means of a fixed-pH end-point may not be specific to a given acid species. The end-poin

23、t pH value retained is 7,8, corresponding to complete precipitation of Al+3ions in synthetic solutions. Titration of soil extractsto this pH may also include some more weakly ionized species or weak acid organic compounds.2 Normative referencesThe following normative documents contain provisions whi

24、ch, through reference in this text, constitute provisions ofthis International Standard. For dated references, subsequent amendments to, or revisions of, any of thesepublications do not apply. However, parties to agreements based on this International Standard are encouraged toinvestigate the possib

25、ility of applying the most recent editions of the normative documents indicated below. Forundated references, the latest edition of the normative document referred to applies. Members of ISO and IECmaintain registers of currently valid International Standards.ISO 3696, Water for analytical laborator

26、y use Specification and test methodsISO 11260, Soil quality Determination of effective cation exchange capacity and base saturation level usingbarium chloride solutionISO 11464, Soil quality Pretreatment of samples for physico-chemical analysesISO 11465, Soil quality Determination of dry matter and

27、water content on a mass basis Gravimetric method3 PrincipleThe soil sample is extracted in accordance with ISO 11260. The extract is titrated with aNaOH solution up to . The use of phenolphthalein as indicator is allowed, but shall be specified in the testreport.An alternative method for determinati

28、on of the free H+acidity is proposed, in which sodium fluoride is added to thesoil extract before the titration (BaF2precipitates but an excess of NaF is not necessary). Aluminium ions arecomplexed and only the H+acidity is detected during the titration process.Two other optional methods for the det

29、ermination of aluminium are proposed, using respectively flame atomicabsorption spectrometry and inductively coupled plasma emission spectrometry.0,1 mol l10,05 mol l1pH = 7,8DIN EN ISO 14254:2011-09 EN ISO 14254:2011 (E) 4 4ReagentsUse only reagents of recognized analytical grade and distilled or d

30、eionized water for all solutions which shall bestoved in suitable plastics bottles.4.1 Water having an electrical conductivity not higher than at (grade 2 water in accordancewith ISO 3696).4.2 Disodium tetraborate decahydrate (borax),Na2B4O710H2O (molecular mass = 381,5) of a purity ,which should be

31、 stored in a tightly closed bottle.4.3 Buffer solutions for pH-meter calibration.4.3.1 Buffer solution ( ): Dissolve of potassium hydrogen phthalate, C8H5KO4,in water (4.1) and dilute to .4.3.2 Buffer solution ( ): Dissolve of potassium dihydrogen phosphate,KH2PO4, and of disodium hydrogen phosphate

32、, Na2HPO4, in water (4.1) and dilute to .4.3.3 Buffer solution ( ): Dissolve of disodium tetraborate decahydrate,Na2B4O710H2O, in water (4.1) and dilute to .Commercial buffer solutions can be used in accordance with the manufacturers instructions.4.4 Indicators (optional)4.4.1 Methyl orange (colour

33、change between and ): in of water.4.4.2 Methyl red (colour change between and ): in of ethanol.4.4.3 Phenolphthalein (colour change between and ): in of ethanol.4.5 Hydrochloric acid,Dilute of concentrated hydrochloric acid ( ) with water to . Thissolution shall be standardized by means of borax (4.

34、2) following the reaction:5H2O+B4O72+2H+Gae4H3BO3A mass of borax of about dissolved in about of water (4.1) (heat slightly to accelerate dissolution) willneed of a solution of hydrochloric acid containing exactly to be neutralized.An end-point at shall be considered, or methyl red used as indicator.

35、 The concentration of this solution shallbe tested at least every month.A commercial standard solution can be used in accordance with the manufacturers instructions.4.6 Sodium hydroxide solution,Dissolve of carbonate-free sodium hydroxide in water (4.1) and dilute to . This solution shallbe standard

36、ized by titration with the hydrochloric acid solution (4.5) (end point: or methyl orange asindicator).Its concentration shall be tested at least every week and shall be within the range to .With time, this solution can absorb carbon dioxide from the atmosphere. The presence of carbonate can be detec

37、tedby carrying out another titration as described above but down to instead of (or phenolphthaleinas indicator instead of methyl orange). When a difference of volume is observed between the two end-points, then anew solution (4.6) shall be prepared.0,2 mS m125C 99,5 %pH = 4,00 20C 10,21 g 0,01 g1 00

38、0 mlpH = 7,00 20C 3,800 g 0,005 g3,415 g 0,005 g 1 000 mlpH = 9,22 20C 3,800 g 0,005 g1 000 mlpH = 3,0 pH = 4,4 0,100 g 0,005 g 100 mlpH = 4,2 pH = 6,2 0,200 g 0,005 g 100 mlpH = 8,2 pH = 10,00 1,00 g 0,01 g 100 mlc(HCl)=1 mol l183 ml d = 1,19 g ml112 mol l11 000 ml1,928 g 100 ml10 ml 1 mol l1pH = 5

39、c(NaOH)=(1,000 0,025) mol l140,0 g 0,5 g 1 000 mlpH = 3,50,975 mol l11,025 mol l1pH = 8,5 pH = 3,5DIN EN ISO 14254:2011-09 EN ISO 14254:2011 (E) 5 A commercial standard solution can be used in accordance with the manufacturers instructions.4.7 Sodium hydroxide solution,Pipette of the solution (4.6)

40、in a volumetric flask and make up to volume with water (4.1). Store in abottle with a container on top filled with soda lime, regularly renewed, as CO2trap. This solution shall be preparedevery day.4.8 Sodium fluoride solution,Dissolve of sodium fluoride in water (4.1) and dilute to approximately .

41、Adjust the pH to 7,0 withhydrochloric acid (4.5) and the volume to with water (4.1).4.9 Barium chloride dihydrate,4.10 Stock solution of aluminium,Dissolve of aluminium metal (purity ) in of concentrated hydrochloric acid( ) and dilute to with water (4.1). A commercial standard solution can be used

42、inaccordance with the manufacturers instructions.4.11 Working solution of aluminium,Transfer of the aluminium stock solution (4.10) into a volumetric flask of and adjust to the mark withwater (4.1).4.12 Barium chloride solution,Dissolve of barium chloride (4.9) in approximately of water (4.1). Trans

43、fer the solution into avolumetric flask and adjust to the mark with water (4.1).4.13 Calibrations solutionsTransfer respectively , and aliquots of the working solution (4.11) in volumetric flasks, dilutewith approximately of water (4.1) and add of barium chloride solution (4.12). Finally adjust the

44、volumewith water (4.1). A fourth solution is prepared in the same way but without aluminium so as to constitute thecalibration blank.5Apparatus5.1 Usual laboratory glassware, including a burette graduated in intervals of or smaller.5.2 pH-meterSet up following the manufacturers instructions and cali

45、brate with buffer solutions (4.3).5.3 Magnetic stirrer5.4 Automatic titrimeter (optional)Set up following the manufacturers instructions and calibrate with buffer solutions (4.3). Results shall be expressedrelatively to an end-point of .5.5 Flame atomic absorption spectrometerEquip with a nitrous ox

46、ide/acetylene burner and set up following the manufacturers instructions. Determination ofaluminium is commonly carried out at a wavelength of .c(NaOH)=50 103mol l11,25 103mol l150 ml 1 000 mlc(NaF)=1 mol l142,0 g 0,2 g 900 ml1 000 mlBaCl22H2O1,000 g l11,000 g 0,001 g 99,9 % 20 mld = 1,19 g ml11 000

47、 ml0,100 g l110 ml 100 mlc(BaCl2)=0,5 mol l112,21 g 0,01 g 60 ml100 ml5 ml 10 ml 20 ml 100 ml20 ml 20 ml0,05 mlpH = 7,8396,2 nmDIN EN ISO 14254:2011-09 EN ISO 14254:2011 (E) 6 5.6 Inductively coupled plasma spectrometerSet up following the manufacturers instructions. Determination of aluminium is co

48、mmonly carried out withbackground correction at various wavelengths such as or .6Sample6.1 Barium chloride extract, obtained in accordance with ISO 11260.6.2 Blank extract, obtained in the same way.7 Procedure7.1 Total exchangeable acidityPipette of the extract (6.1) into a container of sufficient c

49、apacity to also receive the electrodes of the pH-meter(5.2). Introduce a bar magnet and set up the speed of the magnetic stirrer (5.3). Insert the electrodes and titrate withthe sodium hydroxide solution (4.7) until a pH value of 7,8 is reached and remains stable for .When phenolphthalein is used, titrate until the colour just turns permanently pink (in practice wait about ). Titrateof the blank solution (6.2) in the same way in order to obtain a blank value.7.2 Free H+acidity (optional)Pipette of the extract (6.1)