1、BRITISH STANDARD BS EN ISO 3696:1995 Incorporating Amendment No. 1 Water for analytical laboratory use Specification and test methods The European Standard EN ISO 3696:1995 has the status of a British StandardBSENISO3696:1995 This British Standard, having been prepared under the directionof the Chem
2、icals Standards Committee, was published under the authority ofthe Board of BSI and comes intoeffect on 31 December 1987 BSI 10-1999 First published February 1966 First revision December 1987 The following BSI references relate to the work on this standard: Committee reference CIC/26 Draft for comme
3、nt 83/55146 DC ISBN 0 580 16312 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Chemicals Standards Committee (CIC/-) to Technical Committee CIC/26, upon which the following bodies were represented: British Pharmacopoeia Commission Che
4、mical Industries Association Institute of Petroleum Milk Marketing Board Royal Society of Chemistry Society of Glass Technology Textile Institute The following bodies were also represented in the drafting of the standard, through subcommittees and panels: British Ceramic Research Association British
5、 Effluent and Water Association Standardization of Tar Products Tests Committee Amendments issued since publication Amd. No. Date of issue Comments 8807 September 1995 Indicated by a sideline in the marginBSENISO3696:1995 BSI 10-1999 i Contents Page Committees responsible Inside front cover National
6、 foreword ii Foreword 2 1 Scope and field of application 3 2 Description 3 3 Classification 3 4 Requirements 3 5 Sampling 3 6 Storage 3 7 Methods of test 4 8 Test reports 6 Table Requirements 4BSENISO3696:1995 ii BSI 10-1999 National foreword This British Standard has been prepared under the directi
7、on of the Chemicals Standards Committee. It is identical with ISO3696:1987 “Water for analytical laboratory use Specification and test methods”, published by the International Organization for Standardization (ISO). In 1995 the European Committee for Standardization (CEN) accepted ISO3696:1987 as Eu
8、ropean Standard EN ISO3696. As a consequence of implementing the European Standard this British Standard is renumbered as BSEN ISO3696 and any reference to BS3978 should be read as a reference to BS EN ISO3696. This standard is a revision of BS3978:1966, which is withdrawn. The principal changes in
9、this edition are as follows. a) The single grade of water has been replaced by three grades, of which grade3 is roughly equivalent to the water specified in the previous edition. b) Residue on ignition is no longer specified and the requirement (for grade3 water) for residue on evaporation has been
10、tightened. c) Electrical conductivity is now measured at25C instead of20C, and the requirement for grade3 water has been changed from1mS/m to0.5mS/m. d) The limit for oxidizable matter for grade3 water has been tightened. e) Requirements for ammonia content, chloride content and sulphate content are
11、 no longer included. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especial
12、ly to the following. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. The symbol “l” has been used to denote litre (and in its submultiples). In British Standards it is current practice to use the symb
13、ol “L”. The spelling “sulfur”, etc.has been used. In British Standards it is current practice to use the spelling “sulphur”, etc. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. Additional information. If water complying with
14、 BS3978 is specified in another British Standard without stating which grade should be used, it is recommended that grade3 be used (see clause3). Textual errors. When adopting the text of the International Standard, the textual errors listed below were discovered. They have been marked in the text a
15、nd have been reported to ISO in a proposal to amend the text of the International Standard. a) In the note to clause5 the cross-reference should read “see note2 to clause4”. b) In paragraph 1, line3 of7.6.1.1, the reference should be to7.6.2.1 and not7.5.2.3. In paragraph 1, line4 of7.6.1.1, “mix th
16、e sample with a dry” should read “mix with the sand using a dry”.BSENISO3696:1995 BSI 10-1999 iii A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard do
17、es not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi toiv, theENISOtitle page, pages2 to6 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This wil
18、l be indicated in the amendment table on the inside front cover.iv blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM ENISO 3696 April1995 ICS 71.040.30 Descriptors: Inorganic chemistry, chemical analysis, chemical reagents, water, classification, specification, tests, storage English version Wa
19、ter for analytical laboratory use Specification and test methods (ISO 3696:1987) Eau pour laboratoire usage analytique Spcification et mthodes dessai (ISO3696:1987) Wasser fr analytische Laborzwecke- Spezifikation und Prfverfahren (ISO3696:1987) This European Standard was approved by CEN on 1995-02-
20、13. 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 bibliographical references concerning such national standards may be obtained
21、on application to the Central Secretariat 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 Central Secretari
22、at has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CEN European Committee for
23、Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue 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 3696:1995 EENISO3696:
24、1995 BSI 10-1999 2 Foreword The text of the International Standard has been taken as a European Standard by the Technical Committee CEN/TC19, Petroleum products, lubricants, and related products, from ISO/TC47, Chemistry, of the International Organization for Standardization (ISO). This European Sta
25、ndard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October1995, and conflicting national standards shall be withdrawn at the latest by October1995. According to the CEN/CENELEC Internal Regulations, the following cou
26、ntries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom.ENISO3696:1995 BSI 10-1999 3 1 Scope and field of application This Inter
27、national Standard specifies the requirements and corresponding test methods for three grades of water for laboratory use for the analysis of inorganic chemicals. It is not applicable to water for organic trace analysis, to water for the analysis of surface active agents, or to water for biological o
28、r medical analysis. NOTEFor some purposes (for example for certain analytical methods or for tests in which the water is required to be sterile or pyrogen-free or of specified surface tension), additional specific tests and further purification or other treatment may be necessary. 2 Description The
29、material shall be a clear, colourless liquid as assessed by visual inspection. 3 Classification This International Standard covers three grades of water as follows: Grade 1 Essentially free from dissolved or colloidal ionic and organic contaminants and suitable for the most stringent analytical requ
30、irements including those of high-performance liquid chromatography; should be produced by further treatment of grade2 water (for example reverse osmosis or deionization followed by filtration through a membrane filter of pore size0,24m to remove particulate matter or redistillation from a fused sili
31、ca apparatus). Grade 2 Very low in inorganic, organic or colloidal contaminants and suitable for sensitive analytical purposes, including atomic absorption spectrometry (AAS) and the determination of constituents in trace quantities; should be produced, for example, by multiple distillation, or by d
32、eionization or reverse osmosis followed by distillation. Grade 3 Suitable for most laboratory wet chemistry work and preparation of reagents solutions; should be produced, for example, by single distillation, by deionization, or by reverse osmosis. Unless otherwise specified, it should be used for o
33、rdinary analytical work. NOTEIt is assumed that the initial feed stock water is potable and reasonably pure. If it is heavily contaminated in any respect, some pretreatment may be necessary. 4 Requirements The material shall comply with the appropriate requirements of the Table. Testing for complian
34、ce shall be carried out by means of the methods specified in clause7. 5 Sampling A representative sample of the material of not less than2 litres shall be taken from the bulk for the purpose of examination in accordance with this specification. NOTEThis sample is not used for measurements of conduct
35、ivity on grade1 and grade2 water (see7.2.2.1) 1) . The sample shall be placed in a suitable, clean, airtight container, reserved solely for water samples, which shall be of such a size that it is completely filled by the sample. Care shall be taken to avoid the risk of contaminating the contents in
36、any way. Aged containers (i.e.containers boiled for at least2h in a solution of hydrochloric acid, c(HCl). 1mol/l, then twice for1h in distilled water) made of borosilicate glass can be used as well as suitable inert plastics containers (for example polyethylene or polypropylene), but it is essentia
37、l to establish that the sample is unaffected by storage therein, particularly in respect of oxidizable matter and absorbance. 6 Storage Contamination of water during storage may arise principally from dissolution of soluble constituents from glass or plastics containers or absorption of atmospheric
38、carbon dioxide and of any other impurities present in the laboratory atmosphere. For this reason, the storage of grade1 and grade2 water is not recommended, the water being prepared, as required, for immediate use. Nevertheless, grade 2 water may be prepared in reasonable quantity and stored in suit
39、able, inert, clean, airtight, full containers which have been thoroughly pre-rinsed with water of similar grade. The storage of grade3 water presents little problem, but the containers and storage conditions should be the same as those used for the storage of grade2 water. It is recommended that any
40、 storage container be reserved exclusively for the storage of a particular grade of water. 1) See national foreword for details of textual error.ENISO3696:1995 4 BSI 10-1999 Table Requirements 7 Methods of test It is essential that the determinations specified in this clause are carried out in a dus
41、t-free, pure atmosphere and that suitable precautions are taken to prevent any contamination of the sample and test portions. 7.1 Measurement of pH 7.1.1 Apparatus Ordinary laboratory apparatus and pH-meter, fitted with a glass measuring electrode and an Ag/AgCl reference electrode. 7.1.2 Procedure
42、Calibrate the pH-meter (7.1.1) in accordance with the manufacturers instructions, using buffer solutions having pH values covering the range4,0 to8,0. Transfer some of the laboratory sample to a suitable vessel and adjust the temperature of the water to25 1 C. Introduce the electrodes and determine
43、the pH. 7.2 Measurement of conductivity 7.2.1 Apparatus Ordinary laboratory apparatus and 7.2.1.1 Conical flask, fitted with a guard tube containing self-indicating granular soda lime. 7.2.1.2 Conductivity meter with cell for circulation, having an “in-line” conductivity cell, with automatic tempera
44、ture compensation, for measurements on grade1 and grade2 water. NOTEIf the instrument is not temperature-compensated an in-line heat-exchanger, capable of adjusting the temperature of the water under test to25 1 C, should be fitted. 7.2.1.3 Conductivity meter, for measurements on grade3 water. 7.2.2
45、 Procedure 7.2.2.1 Grade 1 and grade 2 water Using the conductivity meter (7.2.1.2), temperature-compensated to25 1 C, measure the conductivity. 7.2.2.2 Grade 3 water Transfer400ml of the sample into the flask(7.2.1.1), insert the guard tube and adjust the temperature of the water to25 1 C. Measure
46、theconductivity by means of the conductivity meter(7.2.1.3) in accordance with the manufacturers operating instructions. Parameter Grade 1 Grade 2 Grade 3 Test method pH value at25C inclusiverange Not applicable (see note 1) Not applicable (see note 1) 5,0 to 7,5 Sub-clause7.1 Electrical conductivit
47、y mS/mat 25C, max. 0,01 (seenote2) 0,1 (see note 2) 0,5 Sub-clause7.2 Oxidizable matter Oxygen(O)content mg/l, max Not applicable (see note 3) 0,08 0,4 Sub-clause7.3 Absorbance at 254nm and1cm optical path length, absorbance units, max. 0,001 0,01 Not specified Sub-clause7.4 Residue after evaporatio
48、n on heating at110C mg/kg, max. Not applicable (see note 3) 1 2 Sub-clause7.5 Silica (SiO 2 ) content mg/l, max. 0,01 0,02 Not specified Sub-clause7.6 NOTE 1Because of the difficulties associated with measurement of the pH value of high-purity water, and the doubtful significance of the value obtain
49、ed, limits for the pH of grade1 and grade2 water have not been specified. NOTE 2The values of conductivity for grade1 and grade2 water apply to freshly prepared water; during storage, it is possible for contaminants such as atmospheric carbon dioxide and alkalis from glass containers to be dissolved, leading to changes in conductivity. NOTE 3A limit for oxidizable matter and residue after evaporation for grade1 water is not specified because of the difficulty of testing for compliance at this level of purity. The quality of grade1 water
