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1、BRITISH STANDARD BS EN ISO 9963-2:1996 BS 6068-2.52: 1996 Water quality Determination of alkalinity Part 2: Determination of carbonate alkalinity The European Standard EN ISO 9963-2:1995 has the status of a British Standard ICS 13.060.40 Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 01:40:5
2、3 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 9963-2:1996 This British Standard, having been prepared under the direction of the Health and Environment Sector Board, was published under the authority of the Standards Board and comes into effect on 15 April 1996 BSI 08-1999 The following BSI
3、 references relate to the work on this standard: Committee reference EH/3/2 Draft for comment 92/53921 ISBN 0 580 25292 2 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee EH/3, Water quality, to Subcommittee EH/3/2, Physic
4、al, chemical and biochemical methods, upon which the following bodies were represented: The Association of the Laboratory Supply Industry British Agrochemicals Association Ltd. British Ceramic Research British Gas plc British Soft Drinks Association Ltd. Chemical Industries Association Convention of
5、 Scottish Local Authorities Department of the Environment (Water Directorate) Department of Trade and Industry (Laboratory of the Government Chemist) GAMBICA (BEAMA) Ltd. Industrial Water Society Institution of Water and Environmental Management National Rivers Authority Royal Society of Chemistry S
6、oap and Detergent Industry Association Society of Chemical Industry Swimming Pool and Allied Trades Association Ltd. Water Companies Association Water Research Centre Water Services Association of England and Wales Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun s
7、heffieldun, na, Sat Nov 18 01:40:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 9963-2:1996 BSI 08-1999i Contents Page Committees responsibleInside front cover National forewordii Foreword2 1Scope3 2Normative references3 3Definition3 4Principle3 5Reagents3 6Apparatus5 7Sampling and sample t
8、reatment5 8Procedure5 9Expression of results6 10Test report6 Annex A (informative) Information on factors for the conversion of alkalinity values to alternative units8 Annex B (informative) Bibliography8 Annex ZA (normative) Normative references to international publications with their relevant Euro
9、pean publications8 Figure 1 Principle for absorption of carbon dioxide from air4 Table 1 Precision data6 Table 2 Comparison of results using this method with other methods for the determination of alkalinity7 Table A.18 List of referencesInside back cover Licensed Copy: sheffieldun sheffieldun, na,
10、Sat Nov 18 01:40:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 9963-2:1996 ii BSI 08-1999 National foreword This British Standard has been prepared by Subcommittee EH/3/2 and is the English language version of EN ISO 9963-2:1995 Water quality Determination of alkalinity Part 2: Determinati
11、on of carbonate alkalinity, published by the European Committee for Standardization (CEN). It is identical with ISO 9963-2:1994, published by the International Organization for Standardization (ISO). A British Standard does not purport to include all the necessary provisions of a contract. Users of
12、British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references Publication referred toCorresponding British Standard ISO 3696:1987BS 3978:1987 Specification for water for laboratory use B
13、S EN 25667 Water quality Sampling EN 25667-1:1993 (ISO 5667-1:1980) Part 1:1994 Guidance on the design of sampling programmes EN 25667-2:1993 (ISO 5667-2:1991) Part 2:1993 Guidance on sampling techniques BS 6068 Water quality Part 1 Glossary ISO 6107-2:1989Section 1.2:1990 Additional terms relating
14、to types of water, and treatment and storage of water and waste water, and terms used in sampling and analysis of water ISO 9963-1:1994BS EN ISO 9663 Water quality Determination of alkalinity Part 1 Determination of total and composite alkalinity IEC 746-2:1982BS 6438 Electrochemical analyzers Part
15、2:1984 Method for specifying performance of pH value analyzers Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN ISO title page, pages 2 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have h
16、ad amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 01:40:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 9963-2 December 1995 ICS 13.060.40
17、Descriptors: Water, quality, water tests, chemical analysis, determination, alkalinity, volumetric analysis English version Water quality Determination of alkalinity Part 2: Determination of carbonate alkalinity (ISO 9963-2:1994) Qualit de leau Dtermination de lalcalinit Partie 2: Dtermination de la
18、lcalinit carbonate (ISO 9963-2:1994) Wasserbeschaffenheit Bestimmung der Alkalinitt Teil 2: Bestimmung der Carbonatalkalinitt (ISO 9963-2:1994) This European Standard was approved by CEN on 1995-10-11. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the cond
19、itions 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 Central Secretariat or to any CEN member. This European Standard exists in three
20、 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 Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Aust
21、ria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: ru
22、e de Stassart 36, B-1050 Brussels 1995 All rights of reproduction and communication in any form and by any means reserved in all countries to CEN and its members. Ref. No. EN ISO 9963-2:1995 E Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 01:40:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI
23、EN ISO 9963-2:1995 BSI 08-1999 2 Foreword The text of the International Standard from ISO/TC 147, Water quality, of the International Organization for Standardization (ISO) has been taken over as a European Standard by the Technical Committee CEN/TC 230, Water analysis. This European Standard consis
24、ts of the following Parts: EN ISO 9963-1, Determination of total and composite alkalinity. EN ISO 9963-2, Determination of carbonate alkalinity. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by Jun
25、e 1996, and conflicting national standards shall be withdrawn at the latest by June 1996. According to the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Lu
26、xembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom. NOTENormative references to International Standard are listed in Annex ZA (normative). Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 01:40:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 9963-2:1995 BS
27、I 08-19993 1 Scope This part of ISO 9963 specifies a method for the titrimetric determination of carbonate alkalinity in natural and drinking water. Using a higher pH value for the endpoint than the method specified in ISO 9963-1, the influence of other hydrogen acceptors, such as anions of humic ac
28、ids, is reduced by the procedure. The method is intended for samples with a carbonate alkalinity between 0,01 mmol/l and 4 mmol/l (as H+ equivalents). For samples containing higher concentrations of alkalinity, a smaller test portion can be used for analysis. In this context, carbonate alkalinity is
29、 often called total alkalinity and usually has nearly the same numerical value as methyl orange alkalinity (MO-alkalinity). The endpoint detection, using a pH-meter is less prone to interferences than the use of the indicator. 2 Normative references The following standards contain provisions which,
30、through reference in this text, constitute provisions of this part of ISO 9963. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO 9963 are encouraged to investigate the possibility of applying the
31、 most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 385-1:1984, Laboratory glassware Burettes Part 1: General requirements. ISO 3696:1987, Water for analytical laboratory use Specification and test methods.
32、 ISO 5667-2:1991, Water quality Sampling Part 2: Guidance on sampling techniques. ISO 6107-2:1989, Water quality Vocabulary Part 2. ISO 9963-1:1994, Water quality Determination of alkalinity Part 1: Determination of total and composite alkalinity. IEC 746-2:1982, Expression of performance of electro
33、chemical analyzers Part 2: pH value. 3 Definition For the purposes of this part of ISO 9963, the following definition applies. 3.1 alkalinity (A) the quantitative capacity of aqueous media to react with hydrogen ions ISO 6107-2 in this method, the endpoint is chosen in such a way as to permit the fu
34、ll neutralization of the carbonate system usually proton acceptors (X) other than the carbonate system are present in low concentrations and can often be disregarded. Examples of such buffering substances are ammonia, phosphate, and anions of humic and other organic acids 4 Principle Alkalinity is d
35、etermined by titration with hydrochloric acid, with simultaneous removal of carbon dioxide. In this way, a precise endpoint independent of the initial concentration of alkalinity can be used. The endpoint preferably needs to be as close to neutrality as possible but still low enough to allow the rem
36、oval of carbon dioxide produced. In this part of ISO 9963, the endpoint is set at pH 5,4, since the pH value can easily be determined with the indicator chosen. The induced systematic error is corrected by titrating a blank. 5 Reagents Use only reagents of recognized analytical grade. Commercially a
37、vailable, ready-made solutions may be used. Licensed Copy: sheffieldun sheffieldun, na, Sat Nov 18 01:40:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 9963-2:1995 4 BSI 08-1999 5.1 Water, grade 2 in accordance with ISO 3696, free of interfering concentrations of acid or alkali and with a cond
38、uctivity of less than 0,1 mS/m. 5.2 Gas, free from carbon dioxide, nitrogen or alternatively a gas free from carbon dioxide obtained by passing air through a standing tube filled with soda lime or another compound that absorbs carbon dioxide. Then pass the gas through a wash bottle containing water
39、and subsequently the gas distribution tube (see Figure 1). 5.3 Mixed indicator pH 5,4 Dissolve 0,040 g 0,005 g of methyl red and 0,060 g 0,005 g of bromocresol green in 100 ml of ethanol 90 % (V/V). Neutralize the solution with about 2 ml of 0,1 mol/l sodium hydroxide until a brown colour appears. C
40、heck the neutrality of the indicator solution by titration to endpoint of one sample. If the brown colour does not remain after the addition of 10 more drops of the indicator, adjust the pH of the indicator solution. Stored in an amber glass bottle, the solution is stable for at least 6 months. Sodi
41、um carbonate solution, c(Na2CO3) . 0,025 mol/l. Dry sodium carbonate (Na2CO3) in an oven at 250 C 10 C for 4 h. Allow to cool in a desiccator. Dissolve 1,3 g 0,1 g (weighed to the nearest 0,001 g) in water in a 500 ml volumetric flask. This solution is stable for at least one month if stored in a re
42、frigerator. 5.4 Hydrochloric acid, c(HCl) . 0,020 mol/l. Dilute 1,7 ml 0,1 ml of concentrated hydrochloric acid ( . 1,18 g/ml) to 1 000 ml with water in a volumetric flask. An equivalent, commercially available solution can be used. Standardize this solution at least weekly as follows. Pipette 2,00
43、ml 0,02 ml of the sodium carbonate solution () into the titration vessel (6.2) and add 40 ml 5 ml of water (5.1). Titrate according to the procedure using electrodes (see 8.1) or with indicator (8.2) for the endpoint detection Figure 1 Principle for absorption of carbon dioxide from air Licensed Cop
44、y: sheffieldun sheffieldun, na, Sat Nov 18 01:40:53 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 9963-2:1995 BSI 08-19995 Perform at least three titrations, and record the volumes (V2) of hydrochloric acid consumed. The difference between the highest and lowest volume of hydrochloric acid consu
45、med shall be less than 0,05 ml. Continue until three consecutive titrations give the required result. Using 50 ml 5 ml of water (5.1), carry out a blank determination in the same manner and note the volume V3, in millilitres, of acid consumed. Calculate the concentration of the hydrochloric acid usi
46、ng the equation where 6 Apparatus Usual laboratory equipment and, in particular, the following should be used. 6.1 Burette, preferably of total capacity 10 ml, graduated in divisions of 0,02 ml, and conforming to the requirements of ISO 385-1. 6.2 Titration vessel, use either a glass filter funnel w
47、ith a porosity of 2-3 and a volume of about 75 ml, or a gas distribution tube for dipping into the titration vessel (an Erlenmeyer flask with a volume of 100 ml). 6.3 pH-meter, with a compatible electrode system suitable for the measurement of pH to within 0,05 pH units over the range 3 to 10, for u
48、se when the endpoint determination is to be made using a pH-meter. The equipment shall be set up, calibrated, and used according to IEC 746-2. Alternatively, a titrator fulfilling these specifications can be used. 7 Sampling and sample treatment Collect samples in clean polyethylene or borosilicate
49、glass bottles with a volume of at least 100 ml. Fill the bottle completely with the sample and insert the stopper so that no air remains inside the bottle. Analyse the samples immediately after collection. If this is not possible, store the samples at a temperature of 4 C to 8 C in order to avoid nitrification or scaling. (See ISO 5667-2.) 8 Procedure Mount the components according to Figure 1. NOTE 1Coloured samples interfere with the indicator endpoint determination. Such samples