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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 1622 : 1998 The Eur
2、opean Standard EN 1622 : 1997 has the status of a British Standard ICS 13.060.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Water analysis Determination of the threshold odour number (TON) and threshold flavour number (TFN) Licensed Copy: sheffieldun sheffieldun, na, Fri
3、Nov 17 08:05:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 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 March 1998 BSI 1998 ISBN 0 580 28873 0 BS EN 162
4、2 : 1998 Amendments issued since publication Amd. No.DateText affected National foreword This British Standard is the English language version of EN 1622 : 1997 published by the European Committee for Standardization (CEN). The UK participation in its preparation was entrusted by Technical Committee
5、 EH/3, Water quality, to Subcommittee EH/3/2, Physical, chemical and biochemical methods, which has the responsibility to: aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests infor
6、med; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Further information Users of this standard are informed that the UK submitted a vote of disapproval on the
7、 final voting stage of the draft EN for the following reasons: While most of the standard is presented in a satisfactory manner, the main procedural clause, clause 10, is unclear in structure, confusing and almost impossible to follow to a user who is not already familiar with the test. This is not
8、helped by the multiplicity of methods presented in the procedural clause thereby making any truly international comparison virtually impossible. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standard
9、s Catalogue under the section entitled International Standards Correspondence Index, or by using the Find facility of the BSI Standards Electronic Catalogue. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front
10、 cover, an inside front cover, the EN title page, pages 2 to 12, an inside back cover and a back cover. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 08:05:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI CEN European Committee for Standardization Comite Europe en de Normalisation Europa ische
11、s Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1622 : 1997 E EUROPEAN STANDARDEN 1622 NORME EUROPE ENNE EUROPA ISCHE NORM October 1997 ICS 13.060
12、.20 Descriptors: Water tests, water, quality, chemical analysis, sensory analysis, determination, taste, odours, quantitative analysis English version Water analysis Determination of the threshold odour number (TON) and threshold flavour number (TFN) Analyse de leau De termination du seuil dodeur (T
13、ON) et du seuil de flaveur (TFN) Wasserbeschaffenheit Bestimmung des Geruchsschwellenwerts (TON) und des Geschmacksschwellenwerts (TFN) This European Standard was approved by CEN on 4 September 1997. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the condit
14、ions 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 o
15、fficial 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 Austri
16、a, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 08:05:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 2
17、EN 1622 : 1997 BSI 1998 Foreword This European Standard has been prepared by Technical Committee CEN/TC 230, Water analysis, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement,
18、 at the latest by April 1998, and conflicting national standards shall be withdrawn at the latest by April 1998. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech R
19、epublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Annex A is normative. Annexes B, C, D and E are informative. Contents Page Foreword2 Introduction3 1Scope3 2Normative references3
20、 3Definitions3 4Principle3 5Hazards4 6Test environment4 7Apparatus and reagents4 8Sampling and sample preservation4 9Test panel and selected assessors4 10Procedure4 11Expression of results7 12Test report7 Annexes A(normative) Chlorinated water8 B(informative) Method for the preparation of reference
21、water8 C(informative) Selection of the test panel8 Dinformative) Preparation of dilutions10 E(informative) Interlaboratory tests11 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 08:05:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 3 EN 1622 : 1997 BSI 1998 Introduction This European Stan
22、dard gives methods for the determination of the threshold odour number (TON) and the threshold flavour number (TFN). The methods described in this European Standard are based on the standard methods for sensory analysis. However, some differences are noted, as compared with those methods, due to wat
23、er specificity. This European Standard is primarily intended to give a quantitative measure of odour and flavour of a water sample at a temperature of 25 8C. NOTE. The method can be used to determine the odour and flavour of a water sample at other temperatures but there will be no correlation betwe
24、en results obtained at different temperatures. 1 Scope This European Standard specifies methods for determining the TON and TFN of waters. It is essential that the safety remarks in clause 5 are taken into account. Two methods are described. A short method applicable when either a sample has no odou
25、r and flavour or when the odour and flavour are to be compared with a specified threshold number. A full method applicable when the threshold number for the sample is to be determined. Both methods are applicable for quantifying the odour and flavour of drinking water and/or migration waters from ma
26、terials in contact with waters. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, su
27、bsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. ISO 3591 : 1977Sensory analysis Apparatus Wine-tasting glass ISO 5
28、492 : 1992Sensory analysis Vocabulary ISO 8589 : 1988Sensory Analysis General guidance for the design of test rooms ISO 7393-2 : 1985Water quality Determination of free chlorine and total chlorine Part 2: Colorimetric method using N,N-diethyl-1,4-phenylenediamine, for routine control purposes 3 Defi
29、nitions For the purposes of this standard, the following definitions apply: 3.1 odour Organoleptic attribute perceptible by the olfactory organ on sniffing certain volatile substances ISO 5492 : 1992. 3.2 flavour Complex combination of the olfactory, gustatory and trigeminal sensations perceived dur
30、ing tasting. The flavour may be influenced by tactile, thermal, painful and/or kinaesthetic effects ISO 5492 : 1992. 3.3 threshold odour number (TON) Dilution ratio beyond which the diluted sample does not have any perceptible odour. TON = A + B A where: Ais the volume of sample; Bis the volume of r
31、eference water. 3.4 threshold flavour number (TFN) Dilution ratio beyond which the diluted sample does not have any perceptible flavour. TFN = A + B A where: Ais the volume of sample; Bis the volume of reference water. 3.5 reference water The water described as without any odour and flavour. NOTE. F
32、or guidance on reference waters, see annex B. 3.6 test panel A group of selected assessors used to evaluate flavour and odour. NOTE. For guidance on the selection of the test panel, see annexes C and E. 3.7 selected assessor Assessor chosen for his/her ability to perform a sensory test ISO 5492 : 19
33、92. 4 Principle The odour and flavour of a water sample are assessed by a test panel by comparing that sample and/or dilutions of that sample with a reference water. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 08:05:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 4 EN 1622 : 1997 BSI 1
34、998 5 Hazards Care shall be taken to ensure that the samples are safe for selected assessors. If there is any suspicion of the presence of harmful micro-organisms or of toxic substances at a toxic concentration, the samples shall not be tested without further precautions being taken. Depending on th
35、e type of sample being tested, the selected assessors shall be instructed not to swallow any test sample. 6 Test environment The room used for odour and flavour assessment has to be free from obtrusive draughts and noise and the general environment such that the selected assessors can perform their
36、task unobserved so that they are not influenced by other selected assessors. No air fresheners or room deodorizers shall be used in the room. The room shall be sited away from any activity that could generate interfering odours. The temperature of the room shall be (232) 8C. It is advisable that thi
37、s room is only used for odour and flavour assessment. Suggestions on the design of suitable facilities are given in ISO 8589 : 1988. 7 Apparatus and reagents 7.1 Glassware Glassware shall be reserved solely for TON and TFN assessment, shall be cleaned separately from other laboratory items and, when
38、 not in use, shall be stored in clean conditions in order to avoid accidental contamination. Sample bottles, tasting glasses and volumetric glassware shall be cleaned before use so that they have no perceptible influence on the result of the assessment. Tasting glasses can be as specified by ISO 359
39、1 : 1977. NOTE. Sample bottles should be of glass and of a suitable capacity. Stoppers should be of glass or polytetrafluoroethene (PTFE) and capable of yielding no headspace in the sample. 7.2 Water bath or incubator Capable of maintaining an homogeneous temperature of (251) 8C. 7.3 Reference water
40、 Odour and flavour free water used for rinsing, dilution and reference, preferably appropriate to the area and where possible similar in mineral character to the type of water being tested. See annex B. 7.4 Cleaning liquids Use one of the following cleaning liquids for glassware. 7.4.1 Non-perfumed
41、biodegradable laboratory detergent. 7.4.2 Hydrochloric acid, c(HCl) 2 mol/l. 7.4.3 Hydrogen peroxide, w(H2O2) approximately 3 %. 8 Sampling and sample preservation Collect the samples (with no headspace) in the clean, well stoppered sample bottles (see 7.1). Keep the samples cool and in the absence
42、of light during transportation and storage. If storage is necessary, store in a refrigerator at (42) 8C. Storage time shall be as short as possible, in no case longer than 72 h, and be specified with the result. 9 Test panel and selected assessors A test panel shall consist of at least three selecte
43、d assessors (see 3.7) for unforced choice (see clause 10) and eight selected assessors (see 3.7) for forced choice (see clause 10). Selected assessors shall be trained and have known sensitivities to specific substances (descriptors) describing odours and flavours such as earthy, musty, aromatic or
44、plasticizer. NOTE. When a new test panel is started, the selected assessors will be untrained but will undergo training with flavours and odours to increase their precision. It is accepted that after a period of training and experience, the test panel will become both more selective and more precise
45、 than the general population. New selected assessors shall be introduced to the odour and flavour test method by an experienced selected assessor or consultant. Selected assessors shall have gained experience in the method before being integrated into regular test panel sessions. Selected assessors
46、shall be willing to serve, and shall be disqualified if they suffer from allergy or of unusual sensitivity. It is desirable that the sensitivities in a test panel to odour and flavour do not differ widely. The performance of individual selected assessors and test panels shall be monitored. This shal
47、l be done by recording the results of each selected assessor during regular work and by interlaboratory tests. The precision of the result is dependent on the test panel size. See annexes C and E for information. 10 Procedure 10.1 General The principle of the method is to quantify the odour and flav
48、our of a sample by the use of a test panel, comparing dilutions of the sample with the reference water. A coordinator organizes the activities of the test panel. Before testing, samples of chlorinated water shall be dechlorinated according to the procedure indicated in annex A. 10.2 Short method 10.
49、2.1 Applicability This short method is applicable when either a sample has no odour and flavour or for compliance of odour and flavour with a specified level. Only one dilution is prepared. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 17 08:05:08 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Page 5 EN 1622 : 1997 BSI 1998 10.2.2 Type of test 10.2.2.1 The triangle test Three test samples, two of which are reference water (see 7.3) and the third, the sample or a dilution of it, are presented simultaneously to the selected assess
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