1、July 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).ICS 71
2、.100.40!$sHH“1803737www.din.deDDIN EN 12829Surface active agents Preparation of water with known calcium and magnesium hardnessEnglish translation of DIN EN 12829:2011-07Grenzflchenaktive Stoffe Herstellung von Wasser mit bekannter Calcium- und MagnesiumhrteEnglische bersetzung von DIN EN 12829:2011
3、-07Agents de surface Prparation dune eau de duret calcique et magnsienne dtermineTraduction anglaise de DIN EN 12829:2011-07SupersedesDIN EN 12829:1997-10www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.1106.11 DIN EN 12829:2011-07
4、2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 276 “Surface active agents” (Secretariat: AFNOR, France). The responsible German body involved in its preparation was the Normenausschuss Materialprfung (Materials Testing Standar
5、ds Committee), Working Committee NA 062-05-63 AA Anwendungstechnische Prfverfahren fr Tenside. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 1773 DIN ISO 1773 EN ISO 3696 DIN ISO 3696 Amendments This standard differs from DIN EN 12829
6、:1997-10 as follows: a) the scope has been extended to include water with known magnesium hardness and the title of the standard has been modified accordingly; b) reagents required for the preparation of water with known magnesium hardness have been included and Clause 7 “Procedure” has been revised
7、; c) Annex A has been extended to include specifications relating to the magnesium hardness; d) the standard has been editorially revised. Previous editions DIN 53910: 1968-05, 1986-09 DIN 53910-1: 1980-04 DIN EN 12829: 1997-10 National Annex NA (informative) Bibliography DIN ISO 1773, Laboratory gl
8、assware Narrow-necked boiling flasks DIN ISO 3696, Water for analytical laboratory use Specification and test methods EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12829 April 2011 ICS 71.100.40 Supersedes EN 12829:1997English Version Surface active agents - Preparation of water with known ca
9、lcium and magnesium hardness Agents de surface - Prparation dune eau de duret calcique et magnsienne dtermine Grenzflchenaktive Stoffe - Herstellung von Wasser mit bekannter Calcium- und Magnesiumhrte This European Standard was approved by CEN on 26 February 2011. CEN members are bound to comply wit
10、h 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 CEN-CENELEC 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 CEN-CENELEC Management Centre has the same sta
12、tus as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portuga
13、l, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE 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 re
14、served worldwide for CEN national Members. Ref. No. EN 12829:2011: EEN 12829:2011 (E) 2 Contents Page Foreword 31 Scope 42 Normative references 43 Terms and definitions .44 Principle 45 Reagents .56 Apparatus .67 Procedure .6Annex A (informative) Units used to express water hardness .8DIN EN 12829:2
15、011-07 EN 12829:2011 (E) 3 Foreword This document (EN 12829:2011) has been prepared by Technical Committee CEN/TC 276 “Surface active agents”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical tex
16、t or by endorsement, at the latest by October 2011, and conflicting national standards shall be withdrawn at the latest by October 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 shall not be held responsi
17、ble for identifying any or all such patent rights. This document supersedes EN 12829:1997. The new edition includes the preparation of water with known magnesium hardness. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to
18、implement this European 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
19、, Switzerland and the United Kingdom. DIN EN 12829:2011-07 EN 12829:2011 (E) 4 1 Scope This European Standard specifies a method of preparing water of known calcium and magnesium hardness for use in testing surface active agents and products containing them. 2 Normative references The following refe
20、renced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN ISO 385, Laboratory glassware Burettes (ISO 385:2005) EN ISO 648
21、, Laboratory glassware Single-volume pipettes (ISO 648:2008) EN ISO 1042, Laboratory glassware One-mark volumetric flasks (ISO 1042:1998) EN ISO 3696:1995, Water for analytical laboratory use Specification and test methods ISO 1773, Laboratory glassware Narrow-necked boiling flasks 3 Terms and defin
22、itions For the purposes of this document, the following terms and definitions apply. 3.1 water hardness Measure for the content of dissolved calcium and magnesium salts and, in special cases, salts of strontium and/or barium NOTE 1 The unit of measurement of water hardness is the millimole per litre
23、 (mmol/l). 1 mmol/l of calcium hardness corresponds to 40,08 mg/l of calcium ions. 1 mmol/l of magnesium hardness corresponds to 24,31 mg/l of magnesium ions. NOTE 2 The equivalents for other degrees of hardness of water, as well as other units used for measuring water hardness and the relationships
24、 between them, are given for information in Annex A. NOTE .3 Originally, the hardness of a sample of water was determined by measuring its power to destroy the foam formed by soap. This property is primarily due to the presence of calcium and magnesium, but salts of other metals, such as iron, alumi
25、nium and manganese, behave in a similar manner, although these seldom occur in natural waters. 4 Principle Preparation of a stock solution by dissolving an appropriate quantity of calcium chloride or magnesium chloride in water. Determination of the calcium or magnesium ions in this stock solution b
26、y complexometric titration with the disodium salt of (ethylenedinitrilo)tetraacetic acid (EDTA) using a mixture of Mordant Black 11 (C.I. 14645) and methyl red as indicator. Preparation of dilute solutions, of the hardness required, by dilution of appropriate volumes of the stock solution. DIN EN 12
27、829:2011-07 EN 12829:2011 (E) 5 5 Reagents 5.1 General WARNING Your attention is drawn to the regulations covering the handling of hazardous substances. Technical, organisational and personal protection measures should be observed. During the analysis, unless otherwise specified, use only reagents o
28、f recognized analytical grade and have been checked in advance as to not interfere with the analytical results and water complying with grade 3 as defined in EN ISO 3696:1995. 5.2 Calcium chloride dihydrate (CaCl2.2H2O), (CAS number: 10035-04-8) If the dihydrate is not available, use an equivalent q
29、uantity of another hydrate or the anhydrous salt. 5.3 Magnesium chloride hexahydrate (MgCl2.6H2O), (CAS number: 7791-18-6) If the hexahydrate is not available, use an equivalent quantity of another hydrate or the anhydrous salt. 5.4 Ammonia solution Dilute 57 ml of ammonia solution (200,90 g/ml) and
30、 1 g of potassium cyanide1)with water to 100 ml. 5.5 Disodium salt of EDTA (Na2EDTA), standard volumetric solution, c(Na2EDTA.2H2O) = 0,05 mol/l, (CAS number : 60-00-4) Dissolve 18,612 g of the disodium salt of (ethylenedinitrilo)tetraacetate (EDTA) dihydrate in water in a 1 000 ml one-mark volumetr
31、ic flask (see 6.1), and make up to the mark with water. 1 ml of this solution, which is stable, is equivalent to 0,05 mmol, i.e. 2,004 mg, of calcium ions or 1,216 mg, of magnesium ions. 5.6 Mixed indicator 5.6.1 Preparation of magnesium-disodium salt of EDTA (MgNa2EDTA), hexahydrate Dissolve 18,6 g
32、 of disodium (ethylenedinitrilo)tetraacetate dihydrate in 75 ml of very hot water ( 80 C). To this solution add 12,3 g of magnesium sulfate heptahydrate dissolved in 25 ml of very hot water ( 80 C). Mix the two solutions thoroughly, cover the mixture and let it cool overnight. Pour off the supernata
33、nt solution and wash the residue three times with cold water, pouring off the washings each time. Wash the crystals with water in a Buchner funnel and dry them under reduced pressure in a desiccator, or in an oven at a temperature of 85 C. 5.6.2 Preparation of mixed indicator Grind 200 mg of Mordant
34、 Black 112)(C.I. 14645) and 37 mg of methyl red with 50 g of ammonium chloride. Add 150 g of ammonium chloride and 10 g of MgNa2EDTA (see 5.5), and continue grinding until a homogeneous mixture is obtained. Store the mixed indicator in a glass bottle with a ground-glass stopper. 1)Potassium cyanide
35、solution may be destroyed by treatment with sodium hypochlorite and hydrogen peroxide. 2)For example Eriochrome Black T. DIN EN 12829:2011-07 EN 12829:2011 (E) 6 NOTE 1 The mixed indicator is prepared and stored as a dry powder because solutions of Mordant Black 11 are unstable; it is used in the gr
36、ound state with ammonium chloride and it reacts with magnesium ions. NOTE 2 The inclusion of MgNa2EDTA allows the indicator to react with calcium or magnesium ions, whilst the addition of methyl red enhances the colour change at the end-point of the titration. NOTE 3 It is also possible to use buffe
37、red indicator tablets instead of the mixed indicator; the colour change is from red to green, via grey. 6 Apparatus Ordinary laboratory apparatus and the following : 6.1 One-mark volumetric flasks, capacity 250 ml and 1 000 ml, complying with EN ISO 1042. 6.2 One-mark pipettes, capacity 25 ml and 50
38、 ml, complying with EN ISO 648. 6.3 Bottle, capacity 5 litres, made of dark-brown glass, with a ground-glass stopper. 6.4 Conical flask, capacity 250 ml, complying with ISO 1773. 6.5 Burette, capacity 50 ml, class A, complying with EN ISO 385. 6.6 Analytical balance. 7 Procedure 7.1 Preparation of s
39、tock solution 7.1.1 Calcium stock solution Dissolve 220,5 g of calcium chloride dihydrate (see 5.2) in water, dilute to 5 litres and store in the bottle (see 6.3). Water of the required calcium hardness can be prepared by dilution from this solution which contains about 300 mmol/l of calcium ions. 7
40、.1.2 Magnesium stock solution Dissolve 305,0 g of magnesium chloride hexahydrate (see 5.2) in water, dilute to 5 litres and store in the bottle (see 6.3). Water of the required magnesium hardness can be prepared by dilution from this solution which contains about 300 mmol/l of magnesium ions. 7.2 De
41、termination of calcium or magnesium content of stock solution Take 50 ml of the stock solution prepared as described in 7.1, using a 50 ml pipette (see 6.2), transfer it to a 250 ml one-mark volumetric flask (see 6.1) and make up to the mark with water. Take 25 ml of the stock solution, using a 25 m
42、l pipette (see 6.2), and transfer to the conical flask (see 6.4). Dilute with about 100 ml of water, and add 4 ml of ammonia solution (see 5.4) from a measuring cylinder and 0,3 g of the mixed indicator (see 5.6). Heat the mixture to about 40 C and titrate it with Na2EDTA solution (see 5.5) to the e
43、nd-point colour change to green. DIN EN 12829:2011-07 EN 12829:2011 (E) 7 Calculate the calcium or magnesium content c0of the stock solution, expressed in millimoles of calcium or magnesium ions per litre, using the equation: cV V00052502510005010= =, where V is the volume, in millilitres, of Na2EDT
44、A solution (see 5.3) used for the titration; 0,05 is the actual concentration, expressed in moles of Na2EDTA.2H2O per litre, of this solution. 7.3 Preparation of water of known calcium or magnesium hardness Calculate the volume V0, expressed in millilitres, of stock solution required to prepare a gi
45、ven volume of solution of known calcium or magnesium hardness from the equation: 0110ccVV = where V1is the required volume, in millilitres, of water of known hardness; c0is the hardness, in millimole per litre of calcium or magnesium ions, of the stock solution calculated in 7.2; c1is the required h
46、ardness, in millimole per litre of calcium or magnesium ions, of the solution of volume V1. Choose the volume V1so that it corresponds to the capacity of a one-mark volumetric flask, and in such a way V0is more than 10 ml and less than 50 ml. Fill the burette (see 6.5) with the stock solution (see 7
47、.1). Transfer the calculated volume V0, measured to the nearest 0,1 ml, of the stock solution to a one-mark volumetric flask of capacity V1and make up to the mark with water. DIN EN 12829:2011-07 EN 12829:2011 (E) 8 Annex A (informative) Units used to express water hardness Table A.1 - Units used to
48、 express calcium water hardness Name of unit Definition Symbol Conversion factors Ca2+CaO CaCO3mmol/l meq/l d mg/kg 1)e a f millimole per litre 1 mmol of calcium ions (Ca2+) in 1 l of water mmol/l 1 2,000 5,600 100 7,020 5,850 0 10,00 milliequivalent per litre 20,04 mg of calcium ions (Ca2+) in 1 l of water meq/l 0,500 1 2,800 50 3,510 2,925 0 5,00 German degree of hardness 10 mg of calcium oxide (CaO) in 1 l of water d 0,178 0,357 1 17,8 1,250 1,044 0 1,78 milligram per kilogram 1 mg of calc
