BS ISO 13165-1-2013 Water quality Radium-226 Test method using liquid scintillation counting《水质 镭-226 使用液体闪烁计数的试验方法》.pdf

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1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 13165-1:2013Water quality Radium-226Part 1: Test method using liquid scintillationcountingBS ISO 13165-1:2013 BRITISH STANDARDNational forewordThis British Standard is the

2、 UK implementation of ISO 13165-1:2013.The UK participation in its preparation was entrusted to TechnicalCommittee EH/3, Water quality.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovis

3、ions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 72184 7ICS 13.060.60; 17.240Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was pub

4、lished under the authority of theStandards Policy and Strategy Committee on 30 April 2013.Amendments issued since publicationDate Text affectedBS ISO 13165-1:2013 ISO 2013Water quality Radium-226 Part 1: Test method using liquid scintillation countingQualit de leau Radium 226 Partie 1: Mthode dessai

5、 par comptage des scintillations en milieu liquideINTERNATIONAL STANDARDISO13165-1First edition2013-04-15Reference numberISO 13165-1:2013(E)BS ISO 13165-1:2013ISO 13165-1:2013(E)ii ISO 2013 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2013All rights reserved. Unless otherwise specified, no pa

6、rt of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member b

7、ody in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 13165-1:2013ISO 13165-1:2013(E) ISO 2013 All rights reserved iiiContents PageForeword ivIntroductio

8、n v1 Scope . 12 Normative references 13 Symbols, definitions and units . 14 Principle 25 Reagents and equipment . 25.1 Reagents 25.2 Equipment . 36 Sampling 37 Instrument set-up and calibration 47.1 Preparation of calibration sources 47.2 Optimization of counting conditions . 47.3 Detection efficien

9、cy. 47.4 Blank sample preparation and measurement 58 Procedure. 58.1 Direct counting 58.2 Thermal preconcentration 58.3 Sample preparation 68.4 Sample measurement 69 Quality control 610 Expression of results 610.1 Calculation of massic activity . 610.2 Standard uncertainty . 610.3 Decision threshold

10、 . 710.4 Detection limit . 710.5 Confidence limits. 810.6 Calculations using the activity concentration 811 Interference control 812 Test report . 9Annex A (informative) Set-up parameters and validation data .10Bibliography .14BS ISO 13165-1:2013ISO 13165-1:2013(E)ForewordISO (the International Orga

11、nization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been establis

12、hed has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization

13、.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Pub

14、lication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent

15、rights.ISO 13165-1 was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 3, Radioactivity measurements.ISO 13165 consists of the following parts, under the general title Water quality Radium-226: Part 1: Test method using liquid scintillation counting Part 2: Test method usi

16、ng emanometryThe following part is under preparation: Part 3: Test method using coprecipitation and gamma-spectrometryiv ISO 2013 All rights reservedBS ISO 13165-1:2013ISO 13165-1:2013(E)IntroductionRadioactivity from several naturally occurring and human-made sources is present throughout the envir

17、onment. Thus, water bodies (surface waters, groundwaters, sea waters) can contain radionuclides of natural and artificial origin (i.e. human-made).a) Natural radionuclides, including potassium-40, and those of the thorium and uranium decay series, in particular radium-226, radium-228, uranium-234, u

18、ranium-238, lead-210, can be found in water for natural reasons (e.g. desorption from the soil and wash-off by rain water) or release from technological processes involving naturally occurring radioactive materials (e.g. the mining and processing of mineral sands or phosphate fertilizer production a

19、nd use).b) Human-made radionuclides such as transuranium elements (americium, plutonium, neptunium, curium), tritium, carbon-14, strontium-90 and gamma-emitting radionuclides can also be found in natural waters as they can be authorized to be routinely released into the environment in small quantiti

20、es in the effluent discharged from nuclear fuel cycle facilities and following their use in unsealed form in medicine or industry. They are also found in water due to fallout from past explosions in the atmosphere of nuclear devices and the accidents at Chernobyl and Fukushima.Drinking water can thu

21、s contain radionuclides at activity concentrations which present a risk to human health. In order to assess the quality of drinking-water (including mineral waters and spring waters) with respect to its radionuclide content and to provide guidance on reducing health risks by taking measures to decre

22、ase radionuclide activity concentrations, water resources (groundwater, river, lake, sea, etc.) and drinking water are monitored for their radioactivity content as recommended by the World Health Organization (WHO).An International Standard on a test method of radium-226 activity concentrations in w

23、ater samples is justified for test laboratories carrying out these measurements, which are sometimes required by national authorities, as laboratories may have to obtain a specific accreditation for radionuclide measurement in drinking water samples.Radium-226 activity concentration can vary widely

24、according to local geological and climatic characteristics and ranges from 0,001 Bq l1in surface waters up to 50 Bq l1in natural groundwaters; the guidance level for radium-226 in drinking water as recommended by WHO is 1 Bq l1(Reference 7).NOTE The guidance level is the activity concentration with

25、an intake of 2 l day1of drinking water for 1 year that results in an effective dose of 0,1 mSv year1for members of the public, an effective dose that represents a very low level of risk that is not expected to give rise to any detectable adverse health effect.This International Standard is one of a

26、series on determination of the activity concentration of radionuclides in water samples. ISO 2013 All rights reserved vBS ISO 13165-1:2013BS ISO 13165-1:2013Water quality Radium-226 Part 1: Test method using liquid scintillation countingWARNING Persons using this part of ISO 13165 should be familiar

27、 with normal laboratory practice. This part of ISO 13165 does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions

28、.IMPORTANT It is absolutely essential that tests conducted in accordance with this part of ISO 13165 be carried out by suitably qualified staff.1 ScopeThis part of ISO 13165 specifies the determination of radium-226 (226Ra) activity concentration in non-saline water samples by extraction of its daug

29、hter radon-222 (222Rn) and its measurement using liquid scintillation counting.Radium-226 activity concentrations which can be measured by this test method utilizing currently available liquid scintillation counters goes down to 50 mBq l1. This method is not applicable to the measurement of other ra

30、dium isotopes.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (includ

31、ing any amendments) applies.ISO 3696, Water for analytical laboratory use Specification and test methodsISO 5667-1, Water quality Sampling Part 1: Guidance on the design of sampling programmes and sampling techniquesISO 5667-3, Water quality Sampling Part 3: Preservation and handling of water sample

32、sISO/IEC 17025, General requirements for the competence of testing and calibration laboratoriesISO 80000-10, Quantities and units Part 10: Atomic and nuclear physicsISO/IEC Guide 98-3:2008, Uncertainty of measurement Part 3: Guide to the expression of uncertainty in measurement (GUM:1995)3 Symbols,

33、definitions and unitsFor the purposes of this document, the definitions, symbols and abbreviations given in ISO 80000-10, ISO/IEC Guide 98-3, and the following apply.a massic activity of the sample at the measuring time, in becquerels per gramaSmassic activity of the 226Ra standard solution at the m

34、easuring time, in becquerels per grama* decision threshold for the massic alpha-activity, in becquerels per gramINTERNATIONAL STANDARD ISO 13165-1:2013(E) ISO 2013 All rights reserved 1BS ISO 13165-1:2013ISO 13165-1:2013(E)a#detection limit for the massic alpha-activity, in becquerels per grama, alo

35、wer and upper limits of the confidence interval, in becquerels per gramcAactivity concentration, in becquerels per litrem mass of the test sample, in gramsm1mass of initial sample subject to heating or possibly concentration, in gramsm2mass of heated or concentrated sample, in gramsm3mass of heated

36、or concentrated sample transferred in the vial, in gramsmSmass of 226Ra standard solution used for the preparation of the calibration sample, in gramsr0blank sample count rate in the alpha-window, in reciprocal secondsrgsample gross count rate in the alpha-window, in reciprocal secondsrScount rate o

37、f the calibration sample in the alpha-window, in reciprocal secondst0blank sample counting time, in secondstgsample counting time, in secondstScalibration sample counting time, in secondsu(a) standard uncertainty associated with the measurement result; in becquerels per gramU expanded uncertainty, c

38、alculated using U = ku(a), with k = 1, 2, in becquerels per gramw factor equal to 1/m alpha-efficiency density, in grams per litre4 Principle226Ra massic activity is determined by liquid scintillation counting of daughter 222Rn at isotopic equilibrium (99,56 %) reached 30 d after the preparation of

39、the sample. The 222Rn is extracted from aqueous solution by means of a scintillation cocktail immiscible with water inside the scintillation vial (References 14).The aqueous sample is acidified, heated and, if possible, concentrated by slow evaporation in order to desorb 222Rn and to achieve a bette

40、r detection limit. The concentrated aqueous sample is transferred into a radon-tight scintillation vial and a water-immiscible scintillation cocktail is added.After 30 d, the sample is measured by liquid scintillation counting (LSC) applying alpha and beta discrimination: only alpha-emission of 222R

41、n and that of its short lived progeny (218Po, 214Po) are considered, as this counting condition ensures a better detection limit.5 Reagents and equipment5.1 ReagentsAll reagents shall be of recognized analytical grade and, except for 5.1.3 and 5.1.4, shall not contain any detectable alpha- and beta-

42、activity.2 ISO 2013 All rights reservedBS ISO 13165-1:2013ISO 13165-1:2013(E)5.1.1 Laboratory water, distilled or deionized, complying with ISO 3696, grade 3.Deionized water can contain detectable amounts of 222Rn and short-lived daughters. It is therefore strongly recommended that water be boiled u

43、nder vigorous stirring and allowed to stand for 1 day before use. Otherwise, flux it with nitrogen for about 1 h for 2 l.5.1.2 Nitric acid, c(HNO3) = 15,8 mol l1, = 1,42 g ml1, mass fraction w(HNO3) = 70 %.5.1.3 Scintillation cocktail, commercially available scintillation cocktails, water immiscible

44、 and suitable for alpha and beta discrimination (e.g. diisopropylnaphthalene-based cocktails).5.1.4 226Ra standard solution226Ra standard solutions shall be provided with calibration certificates containing at least the activity concentration, measurement uncertainty and/or statement of compliance w

45、ith an identified metrological specification.5.2 Equipment5.2.1 Balance.5.2.2 Hotplate with magnetic stirrer and stirring bar.5.2.3 pH-meter.5.2.4 Wide-mouth HDPE sample bottles, volumes between 100 ml and 500 ml.5.2.5 Liquid scintillation counter, with alpha and beta discrimination option, with the

46、rmostated counting chamber and preferably an ultra-low level counter to achieve better detection limits.5.2.6 Polyethylene scintillation vials, PTFE coated, 20 ml.PTFE-coated polyethylene vials are the best choice, since they prevent both the diffusion of the cocktail into the wall of the vial and t

47、he absorption of radon from the environment. Glass vials exhibit a considerably higher background and generally degrade the achievable alpha and beta discrimination.6 SamplingIt is the responsibility of the laboratory to ensure the suitability of this test method for the water samples tested.Collect

48、 the sample in accordance with ISO 5667-1. Store the water sample (from 0,1 l to 1 l) in a plastic bottle (5.2.4) according to ISO 5667-3. When preconcentration is desired, acidify the sample to pH 1 to pH 3 with HNO3(5.1.2). If necessary, carry out filtration immediately on collection and before ac

49、idification.Acidification of the water sample minimizes the loss of radioactive material from solution by plating on the wall of the sample container. If filtration of the sample is required, the acidification is performed afterwards, otherwise radioactive material already adsorbed on the particulate material can be desorbed.If the sample is not acidified, the sample preparation should start as soon as possible and always less than 1 month after the sampling date (ISO 5667-3). ISO 2013 All rights rese