1、BRITISH STANDARDBS ISO 22961:2008Titanium and titanium alloys Determination of iron Atomic absorption spectrometry ICS 77.120.50g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g
2、60g53g44g42g43g55g3g47g36g58BS ISO 22961:2008This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 May 2008 BSI 2008ISBN 978 0 580 57634 8National forewordThis British Standard is the UK implementation of ISO 22961:2008.The UK participation in i
3、ts preparation was entrusted to Technical Committee NFE/35, Light metals and their alloys.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible f
4、or its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate CommentsReference numberISO 22961:2008(E)INTERNATIONAL STANDARD ISO22961First edition2008-01-15Titanium and titanium alloys Determination of
5、iron Atomic absorption spectrometry Titane et alliages de titane Dosage du fer Spectromtrie dabsorption atomique BS ISO 22961:2008ii iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Principle. 1 4 Reagents 1 5 Apparatus 2 6 Sample . 3 7 Procedure 3 8 Expression of results . 5 9
6、Precision 6 Bibliography . 7 BS ISO 22961:2008iv Foreword ISO (the International Organization 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
7、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 work. ISO collaborates closely with the International
8、 Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. 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
9、adopted by the technical committees are circulated to the member bodies for voting. Publication 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
10、patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 22961 was prepared by Technical Committee ISO/TC 79, Light metals and their alloys, Subcommittee SC 11, Titanium. BS ISO 22961:20081Titanium and titanium alloys Determination of iron Atomic absorption
11、 spectrometry 1 Scope This International Standard specifies an atomic absorption spectrometric method for the determination of the mass fraction of iron in titanium and titanium alloys. The method is applicable to titanium and titanium alloys with a mass fraction of iron in the range from 0,005 % to
12、 2,0 %. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 384:1978, Labo
13、ratory glassware Principles of design and construction of volumetric glassware ISO 648:1), Laboratory glassware Single volume pipettes ISO 1042:1998, Laboratory glassware One-mark volumetric flasks ISO 3696:1987, Water for analytical laboratory use Specifications and test methods ISO 4787:1984, Labo
14、ratory glassware Volumetric glassware Methods for use and testing of capacity 3 Principle Dissolve the test portion in hydrochloric acid and hydrofluoric acid. Add nitric acid to oxidize titanium, iron and other elements. Then add boric acid, determine the iron concentration in the test portion usin
15、g an atomic absorption spectrometer. 4 Reagents 4.1 General During the analysis, use only reagents of recognized analytical grade and water that complies with grade 2 of ISO 3696. 1) To be published. (Revision of ISO 648:1977) BS ISO 22961:20082 4.2 Hydrochloric acid (1+1) Add slowly 500 ml of hydro
16、chloric acid (20 1,16 g/ml to 1,19 g/ml) to 500 ml of water. 4.3 Nitric acid (1+1) Add slowly 500 ml of nitric acid (20 1,42 g/ml) to 500 ml of water. 4.4 Hydrofluoric acid (1+1) Add, carefully and slowly, 100 ml of hydrofluoric acid (20 1,14 g/ml) to 100 ml of water. 4.5 Boric acid 4.6 Titanium Tit
17、anium with minimum purity 99 % (mass fraction) and the mass fraction of iron as low as possible, and already known. If the mass fraction of iron is unknown, it should be determined by ISO 22960. 4.7 Iron standard solution 4.7.1 Iron standard stock solution (0,500 mg Fe/ml) Weigh, to the nearest 0,1
18、mg, 0,500 g of iron metal minimum purity 99,9 % (mass fraction) into a 300 ml beaker, heat and decompose with 30 ml of hydrochloric acid (4.2). Add 5ml of nitric acid (4.3) to oxidize iron and heat until nitrogen oxides evaporates. After cooling, transfer to a 1 000 ml volumetric flask, make up to t
19、he mark with water and mix. 4.7.2 Iron standard solution (0,050 mg Fe/ml) Pipette 10,00 ml of iron standard stock solution (4.7.1) to a 100 ml volumetric flask, make up to the mark with water and mix. Prepare this solution on the day of use. 5 Apparatus 5.1 General Use normal laboratory apparatus. 5
20、.2 Volumetric glassware, of class A complying with ISO 384, ISO 648 and ISO 1042. Use in accordance with ISO 4787. 5.3 Analytical balance, sensitive to 0,1 mg. 5.4 Atomic absorption spectrometer. Instrumental conditions: Flame: air/acetylene Wavelength: 248,3 nm BS ISO 22961:200836 Sample 6.1 Sampli
21、ng The sampling procedure for titanium and titanium alloys shall be agreed upon until a corresponding standard method has been published. 6.2 Test portion Extract a test portion of 0,50 g from the test sample and weigh to the nearest 0,1 mg. 7 Procedure 7.1 Number of determinations Carry out the det
22、ermination at least in duplicate, as far as possible under repeatability conditions, on each sample. 7.2 Blank test Carry out a blank test in parallel with the analysis, using the same quantities of all reagents but omitting the test portion. 7.3 Preparation of calibration solution 7.3.1 General Pre
23、pare the calibration solutions in accordance with 7.3.2 or 7.3.3. 7.3.2 In the case of a mass fraction of iron less than 0,1 % Weigh six samples of titanium (4.6), each of 0,50 g, and transfer to polyethylene beakers (200 ml). Add 10 ml of hydrochloric acid (4.2) and 5 ml of hydrofluoric acid (4.4),
24、 cover with a polyethylene watch glass and heat gently on a water bath to decompose the test portion. Add 3 ml of nitric acid (4.3) and continue heating until nitrogen oxides are evaporated. Then add 3 g of boric acid (4.5), stir to dissolve the boric acid and cool to room temperature. Transfer the
25、solution into a 100 ml volumetric flask and add, from a burette or pipette, 0 ml, 2 ml, 4 ml, 6 ml, 8 ml and 10 ml of iron standard solution (4.7.2). Make up to the mark with water and mix. 7.3.3 In the case of a mass fraction of iron more than 0,1 % Weigh 0,50 g of titanium (4.6) and transfer to a
26、polyethylene beaker (200 ml). Add 10 ml of hydrochloric acid (4.2) and 5 ml of hydrofluoric acid (4.4), cover with a polyethylene watch glass and heat gently on a water bath to decompose the titanium. Add 3 ml of nitric acid (4.3) and continue heating until nitrogen oxides are evaporated. Then add 3
27、 g of boric acid (4.5), stir to dissolve the boric acid and cool to room temperature. Transfer the solution into a 100 ml volumetric flask. Pipette 20,0 ml or 5,0 ml of the solution according to the mass fraction of iron in the sample (see Table 1) into six volumetric flasks. Add 8 ml or 9,5 ml of h
28、ydrochloric acid (4.2) according to the mass fraction of iron in the sample (see Table 1). Add, from a burette or pipette, 0 ml, 2 ml, 4 ml, 6 ml, 8 ml and 10 ml of iron standard solution (4.7.2). Make up to the mark with water and mix. BS ISO 22961:20084 7.4 Preparation of test solution for present
29、ation to atomic absorption spectrometer Transfer the test portion to a polyethylene beaker (200 ml). Add 10 ml of hydrochloric acid (4.2) and 5 ml of hydrofluoric acid (4.4), cover with a polyethylene watch glass and heat gently on a water bath to decompose the test portion. Add 3 ml of nitric acid
30、(4.3) and continue heating until nitrogen oxides are evaporated. Then add 3 g of boric acid (4.5), stir to dissolve the boric acid and cool to room temperature. Transfer the solution into a 100 ml volumetric flask, make up to the mark with water and mix. In case the mass fraction of iron is more tha
31、n 0,1 %, pipette 20,0 ml or 5,0 ml of the solution according to the mass fraction of iron in the sample into a 100 ml volumetric flask. Add 8 ml or 9,5 ml of hydrochloric acid (4.2) according to the aliquot volume, and make up to the mark with water (see Table 1). Table 1 Mass fractions of iron and
32、aliquot volume Mass fraction of iron Aliquot volume Added volume of HCl (4.2) % ml ml W 0,1 0,5 W 0,5 u 2 20,0 5,0 8 9,5 7.5 Determination of iron concentration 7.5.1 General The instrument shall be set up with an iron hollow cathode lamp in accordance with the manufacturers recommendation. The wave
33、length shall be set to 248,3 nm. An oxidizing acetylene-air flame is used. When using devices for a computer system preparation of a working curve, standardization (drift correction, normalization, recalibration) and measurement of iron concentration shall be in accordance with the operating manual
34、for the devices computer system software. 7.5.2 Preparation of working curve Spray a portion of the calibration solutions into the air and acetylene flame of an atomic absorption spectrometer of which the zero point has been regulated by using water, measure the absorbance at a wavelength of 248,3 n
35、m, prepare the relation curve between the obtained absorbance and iron concentration in milligrams per 100 ml. Prepare the working curve for a sample by parallel shifting of the relation curve, so as to let the curve pass through the origin of the coordinate axes. 7.5.3 Measurement of iron concentra
36、tion Spray a portion of the test solutions into the air and acetylene flame of an atomic absorption spectrometer of which the zero point has been regulated by using water, measure the absorbance at a wavelength of 248,3 nm, and determine the iron concentration (mg/100 ml) of the test solutions from
37、the working curve. BS ISO 22961:200858 Expression of results 8.1 In the case of a mass fraction of iron less than 0,1 % (m/m) The mass fraction of iron in the test portion, WFe, expressed as a percentage, is given by the following equation: Wm=3123Fe()100 10 (1)where 1is the concentration of iron in
38、 the test solution, expressed in mg/100 ml; 2is the concentration of iron in the blank solution, expressed in mg/100 ml; 3is the concentration of iron in the titanium (4.6) used in 7.3.2 or 7.3.3, expressed in mg/100ml; m is the mass of test portion, expressed in g. Calculate the mass fraction of ir
39、on in the test portion to the third decimal place. The difference in results of two parallel determinations of oxygen content in the same sample shall not be greater than the tolerance Equation (3), (4) or (5). If the difference exceeds the tolerance, the analysis shall be repeated. 8.2 In the case
40、of a mass fraction of iron more than 0,1 % The mass fraction of iron in the test portion, WFe, expressed as a percentage, is given by the following equation: VWm=4533Fe100100 10 (2) where 3is the concentration of iron in the titanium used in 7.3.2 or 7.3.3, expressed in mg/100 ml; 4is the concentrat
41、ion of iron in the aliquot test solution expressed in mg/100 ml; 5is the concentration of iron in the aliquot blank solution expressed in mg/100 ml; V is the volume of aliquot, expressed in ml; m is the mass of test portion, expressed in g. Calculate the mass fraction of iron in the test portion to
42、the third decimal place. The difference in results of two parallel determinations of the mass fraction of iron in the same sample shall not be greater than the tolerance Equation (3), (4) or (5). If the difference exceeds the tolerance, the analysis shall be repeated. BS ISO 22961:20086 9 Precision
43、The tolerance of this analytical method is expressed by the following equations: Repeatability limit 2,8 0,010 0 (WFe) + 0,000 4 % (mass fraction) (3) Within-laboratory-reproducibility limit 2,8 0,014 9 (WFe) + 0,000 4 % (mass fraction) (4) Between-laboratory-reproducibility limit 2,8 0,027 0 (WFe)
44、+ 0,002 3 % (mass fraction) (5) BS ISO 22961:20087Bibliography 1 ISO 22969, Titanium and titanium alloys Determination of iron Molecular absorption spectrometry using 1, 10-phenanthroline BS ISO 22961:2008BS ISO 22961:2008BSI389 Chiswick High RoadLondonW4 4ALBSI British Standards InstitutionBSI is t
45、he independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter.RevisionsBritish Standards are updated by amendment or revision. Users of British Standards should make sure th
46、at they possess the latest amendments or editions.It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible,
47、the identity of which can be found on the inside front cover. Tel: +44 (0)20 8996 9000. Fax: +44 (0)20 8996 7400.BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards.Buying standardsOrders for all BSI, int
48、ernational and foreign standards publications should be addressed to Customer Services. Tel: +44 (0)20 8996 9001. Fax: +44 (0)20 8996 7001. Email: ordersbsi-. Standards are also available from the BSI website at http:/www.bsi-.In response to orders for international standards, it is BSI policy to su
49、pply the BSI implementation of those that have been published as British Standards, unless otherwise requested.Information on standardsBSI provides a wide range of information on national, European and international standards through its Library and its Technical Help to Exporters Service. Various BSI electronic information services are also available which give details on all its products and services. Contact the Information Centre. Tel: +44 (0)20 8996 7111. Fax: +
