1、BSI Standards PublicationBS ISO 17992:2013Iron ores Determinationof arsenic content Hydridegeneration atomic absorptionspectrometric methodBS ISO 17992:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 17992:2013.The UK participation in its preparation was e
2、ntrusted to TechnicalCommittee ISE/58, Iron ores.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Stan
3、dards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 79546 6ICS 73.060.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 September 2013.
4、Amendments issued since publicationDate Text affectedBS ISO 17992:2013 ISO 2013Iron ores Determination of arsenic content Hydride generation atomic absorption spectrometric methodMinerais de fer Dosage de larsenic Mthode par spectromtrie dabsorption atomique gnration dhydrureINTERNATIONAL STANDARDIS
5、O17992First edition2013-09-15Reference numberISO 17992:2013(E)BS ISO 17992:2013ISO 17992:2013(E)ii ISO 2013 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2013All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by a
6、ny 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 body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Ge
7、neva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 17992:2013ISO 17992:2013(E) ISO 2013 All rights reserved iiiContents PageForeword iv1 Scope . 12 Normative references 13 Principle 14 Reagents 15 Apparatus . 36 Sampling and samples
8、 46.1 Laboratory sample . 46.2 Preparation of predried test samples 47 Procedure. 47.1 Number of determinations . 47.2 Test portion 47.3 Blank test and check test 47.4 Determination . 58 Expression of results 78.1 Calculation of mass fraction of arsenic content 78.2 General treatment of results . 78
9、.3 Oxide factor . 109 Test report 10Annex A (normative) Flow sheet of the procedure for the acceptance of analytical values for test sample .13Annex B (informative) Parameters of some instruments 14Annex C (informative) Derivation of repeatability and permissible tolerance formulae 16Annex D (inform
10、ative) Precision data obtained by international analytical trials .17BS ISO 17992:2013ISO 17992:2013(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normall
11、y carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the
12、work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the di
13、fferent approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document
14、 may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/pa
15、tents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO princ
16、iples in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 102, Iron ore and direct reduced iron, Subcommittee SC 2, Chemical analysis.iv ISO 2013 All rights reservedBS ISO 17992:2013INTERNATIONAL ST
17、ANDARD ISO 17992:2013(E)Iron ores Determination of arsenic content Hydride generation atomic absorption spectrometric methodWARNING This International Standard can involve hazardous materials, operations, and equipment, and does not purport to address all of the safety issues associated with its use
18、. It is the responsibility of the user of this International Standard to establish appropriate health and safety practices and determine the applicability of regulatory limitations prior to use.1 ScopeThis International Standard specifies a hydride generation atomic absorption spectrometric method f
19、or the determination of the arsenic content of iron ore.This International Standard is applicable to mass fractions of arsenic between 0,000 66 % and 0,020 15 % in natural iron ores, iron ore concentrates and agglomerates, including sinter products.2 Normative referencesThe following documents, in w
20、hole 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 (including any amendments) applies.ISO 648, Laboratory glassware Single-
21、volume pipettesISO 1042, Laboratory glassware One-mark volumetric flasksISO 3082, Iron ores Sampling and sample preparation proceduresISO 3696, Water for analytical laboratory use Specification and test methodsISO 7764, Iron ores Preparation of predried test samples for chemical analysisISO Guide 35
22、:2006, Reference materials General and statistical principles for certification3 PrincipleThe test portion is decomposed by treatment with hydrochloric and nitric acid. The residue is treated with sodium peroxide and sodium carbonate. Potassium iodide reduces As(V) to As(III) and ascorbic acid masks
23、 the effect of iron in the solution. At optimum acidity of around 26 %, the solution and sodium borohydride react to generate gaseous arsenic hydride. An inert carrier gas is used to transport the arsenic hydride to a quartz tube atomizer. The equipment is set to measure the absorbances at 197,3 nm.
24、 The absorbances of the test and calibration solutions, including those of certified or other reference materials, are compared to determine the arsenic content.4 ReagentsDuring the analysis, use only reagents of recognized analytical grade and Grade 2 water in accordance with ISO 3696.Reagents are
25、to be selected or purified for the lowest possible blank value.4.1 Sodium peroxide (Na2O2). ISO 2013 All rights reserved 1BS ISO 17992:2013ISO 17992:2013(E)4.2 Sodium carbonate (Na2CO3), anhydrous powder.4.3 Sodium bicarbonate (NaHCO3).4.4 Sodium hydroxide (NaOH).4.5 Iron oxide (Fe2O3).4.6 Arsenic t
26、rioxide (As2O3).4.7 Hydrochloric acid, 1,16 g/ml to 1,19 g/ml.4.8 Nitric acid, 1,42 g/ml.4.9 Hydrochloric acid, 1,16 g/ml to 1,19 g/ml, diluted 1+1.4.10 Hydrochloric acid, 1,16 g/ml to 1,19 g/ml, diluted 2+98.4.11 Hydrochloric acid, 1,16 g/ml to 1,19 g/ml, diluted 12+88.4.12 Sodium hydroxide solutio
27、n, 40 g/l.Dissolve 2 g of sodium hydroxide to 10 ml of water; dilute to 50 ml.4.13 Sodium borohydride solution, 8 mg/ml.Dissolve 0,5 g of sodium hydroxide to 10 ml of water, then dissolve 0,8 g of sodium borohydride NaBH4 95 % (m/m) in the 50 ml beaker contained sodium hydroxide solution; dilute to
28、100 ml. This solution shall be freshly prepared and used immediately.4.14 Potassium iodide solution, 100 mg/ml.Dissolve 10 g of potassium iodide KI 98,5 % (m/m) in 20 ml of water. Dilute to 100 ml.4.15 Ascorbic acid solution, 100 mg/ml.Dissolve 10 g of ascorbic acid C6H8O6 99,5 % (m/m) in 20 ml of w
29、ater. Dilute to 100 ml. This solution shall be freshly prepared and used immediately.4.16 Background solution, 10 mg Fe/ml.Dissolve 1,43 g of iron oxide (4.5) minimum purity 99,99 % (m/m) in 30 ml of hydrochloric acid (4.7). Evaporate until a syrupy consistency is obtained, cool, add 10 ml of hydroc
30、hloric acid (4.9), and transfer the solution to a 100 ml one-mark volumetric flask. Dilute to volume with water and mix.4.17 Arsenic standard solution A, 100 g/ml.Dry several hundred milligrams of arsenic trioxide As2O3 99,95 % (m/m) at 105 C for 1 h. Dissolve 0,132 g of the dried product in 2 ml of
31、 sodium hydroxide solution (4.12), add 30 ml of water, neutralize with hydrochloric acid (4.10), using methyl orange (4.21) indicator, and add 4 g of sodium bicarbonate (4.3). Dilute in a volumetric flask to 1 000 ml with water and mix.1 ml of standard arsenic solution A contains 100 g of arsenic.2
32、ISO 2013 All rights reservedBS ISO 17992:2013ISO 17992:2013(E)4.18 Arsenic standard solution B, 1 g/ml.Transfer 10 ml of arsenic standard solution A (4.17) to a 1 l volumetric flask, dilute to the mark with water, and mix.1 ml of standard arsenic solution B contains 1 g of arsenic.4.19 Arsenic stand
33、ard solution C, 0,1 g/ml.Transfer 10 ml of arsenic standard solution B (4.18) to a 100 ml volumetric flask, dilute to the mark with water, and mix.1 ml of standard arsenic solution C contains 0,1 g of arsenic.4.20 Methyl orange, indicator.4.21 Methyl orange solution, 1 mg/ml.Dissolve 0,10 g of methy
34、l orange in 20 ml of water. Dilute to 100 ml.5 ApparatusUse ordinary laboratory apparatus, including one-mark pipettes and one-mark volumetric flasks complying with the specifications of ISO 648 and ISO 1042 respectively, and the following.5.1 Atomic absorption spectrometer, equipped with an arsenic
35、 hollow cathode lamp or electrodeless discharge lamp.WARNING Follow the manufacturers instructions to avoid possible explosion hazards for igniting and extinguishing the air-acetylene flame and possible burning for hot electric furnace. Wear tinted safety glasses whenever the atomic absorption spect
36、rometer is in operation. Good ventilation of the flame is necessary to prevent poison by arsenic hydride.The atomic absorption spectrometer used in this method shall meet the following criteria.a) Minimum sensitivity: The absorbance of the highest concentration calibration solution (see 7.4.3) is at
37、 least 0,25.b) Graph linearity: The slope of the calibration graph covering the top 20 % of the concentration range (expressed as a change in absorbance) is not less than 0,7 of the value of the slope for the bottom 20 % of the concentration range determined in the same way.c) Minimum stability: The
38、 standard deviation of the absorbance of the most concentrated calibration solution and that of the zero calibration solution, each being calculated from a sufficient number of repetitive measurements, are less than 1,5 % and 0,5 %, respectively, of the mean value of the absorbance of the most conce
39、ntrated solution.The use of a strip-chart recorder and/or digital readout device is recommended to evaluate criteria a), b), and c) and for all subsequent measurements.Parameters will vary with each instrument. The parameters in Annex B were successfully used in several laboratories and they can be
40、used as guidelines. An air-acetylene flame or electric furnace capable of reaching temperatures of 900 C to 1 000C is used.5.2 Hydride generator, continuous or discontinuous injection sample hydride generator.An example of continuous injection sample hydride generator is given in Figure 1, and an ex
41、ample of discontinuous injection sample hydride generator is given in Figure 2.5.3 Quartz tube atomizer (T type). ISO 2013 All rights reserved 3BS ISO 17992:2013ISO 17992:2013(E)An example of a quartz tube atomizer is given in Figure 3.5.4 Muffle furnace.5.5 Zirconium crucible, of minimum capacity 2
42、5 ml.5.6 Pipettes.5.7 Volumetric flasks and storage bottles.5.8 Carrier gas supply, inert gas.6 Sampling and samples6.1 Laboratory sampleFor analysis, use a laboratory sample of 100 m particle size that has been taken and prepared in accordance with ISO 3082. In the case of ores containing significa
43、nt contents of combined water or oxidizable compounds, use a particle size of 160 m.NOTE A guideline on significant contents of combined water and oxidizable compounds is incorporated in ISO 7764.6.2 Preparation of predried test samplesThoroughly mix the laboratory sample and, taking multiple increm
44、ents, extract a test sample in such a way that it is representative of the whole contents of the container. Dry the test sample at (105 2) C, as specified in ISO 7764. (This is the predried test sample.)7 Procedure7.1 Number of determinationsCarry out the analysis at least in duplicate in accordance
45、 with Annex A, independently, on one predried test sample.NOTE The expression “independently” means that the second and any subsequent result is not affected by the previous result(s). For this particular analytical method, this condition implies that the repetition of the procedure is carried out e
46、ither by the same operator at a different time or by a different operator including, in either case, appropriate recalibration.7.2 Test portionTaking several increments, weigh, to the nearest 0,000 1 g, approximately 0,5 g of the predried test sample obtained in accordance with 6.2.7.3 Blank test an
47、d check testIn each run, one blank test and one analysis of a certified reference material of the same type of ore shall be carried out parallel with the analysis of the ore sample(s) under the same conditions. A predried test sample of the certified reference material shall be prepared as specified
48、 in 6.2.Where the analysis is carried out on several samples at the same time, the blank value can be represented by one test, provided that the procedure is the same and the reagents used are from the same reagent bottles.4 ISO 2013 All rights reservedBS ISO 17992:2013ISO 17992:2013(E)Where the ana
49、lysis is carried out on several samples of the same type of ore at the same time, the analytical value of one certified reference material can be used.The certified reference material should be of the same type as the sample to be analysed and the properties of the two materials should be sufficiently similar to ensure that, in either case, no significant changes in the analytical procedure will become necessary. Where a certified reference material is not available, a reference mater
