BRITISH STANDARD BS EN 10212 1996 Chemical analysis of ferrous materials — Determination of arsenic in steel and iron — Spectrophotometric method The European Standard EN 10212 1995 has the status of[.]
BRITISH STANDARD Chemical analysis of ferrous materials — Determination of arsenic in steel and iron — Spectrophotometric method The E urop ean S tandard E N 02 : 99 has the s tatus of a Britis h S tandard IC S 40 40 BS EN 10212:1996 BS EN 10212:1996 Committees responsible for this British Standard The p rep aration of this British S tandard was entrusted to Technical C ommittee IS E /1 8, S amp ling and analysis of iron and s teel, up on which the following b odies were rep res ented: BC IRA Britis h Iron and S teel Producers ’ As s ociation Minis try of D efence Welding Ins titute This Britis h S tandard, having b een p rep ared under the direction of the E ngineering S ector Board, was p ub lis hed under the authority of the S tandards Board and comes into effect on Amendments issued since publication Feb ruary 99 Amd No © BS I 1 - 99 The following BS I references relate to the work on this s tandard: C omm ittee reference I S E /1 D raft for com ment /3 8468 D C ISBN 580 25440 D ate C omments BS EN 10212:1996 Contents Page Committees responsib le © BSI 1 - 999 Inside front cover National foreword ii Foreword Text of E N 02 List of references Inside back cover i BS E N 2 : 996 National fore word This British Standard has been prepared by Technical Committee ISE/1 and is Chemical analysis of ferrous materials — Determination of arsenic in steel and iron — Spectrophotometric method, published by the European Committee for Standardization (CEN) It was the English language version of EN 021 2: 995, produced as a result of international discussions in which the United Kingdom took an active part 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 C omp liance with a British S tand ard d oe s no t of itse lf confe r immunity from le gal ob ligatio ns S ummary of p age s This document comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages to 8, an inside back cover and a back cover This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover ii © BSI 1 - 999 EUROPEAN STANDARD EN 021 NORME EUROPÉENNE March 995 EUROPÄISCHE NORM ICS 71 040 40 Descriptors: Iron and steel products, steels, cast iron, chemical analysis, determination of content, arsenic, spectrophotometric analysis English version Chemical analysis of ferrous materials — Determination of arsenic in steel and iron — Spectrophotometric method Analyse chimique des matériaux Chemische Analyse von Eisenwerkstoffen — sidérurgiques — Dosage de l’arsenic dans les Bestimmung von Arsen in Stahl und Eisen aciers et les fontes — Méthode mittels Spektralphotometrie spectrophotométrique This European Standard was approved by CEN on 995- 02- 06 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 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 Secretariat has the same status as the official versions CEN members Denmark, are Finland, the national France, standards Germany, bodies Greece, of Austria, Iceland, Belgium, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung C e ntral Se cre tariat: rue de Stassart 6, B-1 Brusse ls © 995 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 021 2: 995 E EN 10212:1995 Foreword Contents This European Standard was prepared by Technical Committee ECISS/TC 20, Methods of chemical Page Foreword Scope Normative references identical text or by endorsement, at the latest by Principle September 995, and conflicting national standards Reagents Apparatus Sampling Procedure Belgium, Denmark, Finland, France, Germany, Expression of results Greece, Iceland, Ireland, Italy, Luxembourg, Test report analysis, the secretariat of which is held by SIS The European Standard shall be given the status of a national standard, either by publication of an shall be withdrawn at the latest by September 995 According with the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom Annex A (informative) Precision data Figure — Arsine evolution and absorption apparatus Table — Calibration solutions Table A — Certified reference materials tested © BSI 1 - 999 E N 2 : 995 Hydrochloric-nitric acid mixture Add 65 ml nitric acid, approximately Ô 1,40 g/ml, to 100 ml This European Standard specifies a water; add the resulting diluted acid to 60 ml spectrophotometric method for the determination of hydrochloric acid ( ) and mix arsenic in steel and iron The method is applicable Absorption solution Dissolve 1,25 g of silver to all types of steel and iron with arsenic contents diethyldithiocarbamate (C5H10AgNS 2) and 0,825 g from 0,001 % to 0,08 % (m/m ) of 1-ephedrin in approximately 400 ml of trichloromethane (chloroform) in a 500 ml volumetric flask Dilute to the mark with This European Standard incorporates by dated or trichloromethane and mix undated references, provisions from other preparation a small residue may develop publications These normative references are cited After Filter the solution after at least 20 h and store the at the appropriate places in the text and the solution in an amber coloured bottle The solution publications are listed hereafter For dated can be used after the filtration for at least months references, subsequent amendments to or revisions NOTE The peak wavelength of the silver colloid may vary with of any of these publications apply to this European the quality of the reagent and should be determined with each Standard only when incorporated in it by new batch of reagent amendment or revision For undated references the acid, 100 g/l solution This solution latest edition of the publication referred to applies shallAscorbic be freshly prepared each day EURONORM 18:1979, Selection and preparation of Potassium iodide, 150 g/l solution This solution samples and test pieces for steel and iron and steel shall be freshly prepared each day products Tin (II) chloride, 400 g/l in hydrochloric acid solution Dissolve 20 g of tin (II) chloride in approximately 40 ml of hydrochloric acid ( ) Dissolution of a test portion in a mixture of nitric Transfer to a 50 ml volumetric flask, dilute to the and hydrochloric acids followed by evaporation to mark with hydrochloric acid ( ) and mix dryness and prolonged heating of the dried residue This solution shall be freshly prepared each day Extraction of the residue with acid, reduction of the Lead acetate wool Impregnate cotton wool with arsenic (As V to As III) by addition of potassium lead acetate trihydrate solution, (10 g/l), squeeze iodide, ascorbic acid and tin (II) chloride out the excess solution and dry the wool at 105 °C Conversion of the arsenic to arsenic hydride (arsine) for several hours with zinc Arsenic standard solution, corresponding Absorption of the evolved arsine in a solution of to 4g of arsenic per ml Dissolve 0,3301 g of silver diethyldithiocarbamate and 1-ephedrin in arsenic trioxide, dried at 105 °C, in 20 ml sodium trichloromethane hydroxide solution (8 g/l) Transfer to a 000 ml Spectrophotometric measurement of the volumetric flask, dilute to the mark with water and reddish-violet coloured colloid at a wavelength mix Transfer 20,0 ml of this solution to a 000 ml between 500 nm and 520 nm volumetric flask, dilute to the mark with water and mix S cop e 4.5 4.3 4.6 Normative re fe re nce s 4.7 4.8 4.9 Princip le 4.3 4.3 4.1 4.1 Re age nts During the analysis, use only reagents of recognized analytical quality and only distilled water or water of equivalent purity Iron, of high purity, free of arsenic or of known low arsenic content Zinc, of high purity, free of arsenic or of known low arsenic content Zinc shot, 0,5 mm to mm, and zinc pellets, approximately mm in diameter Hydrochloric acid, approximately Ô 1,19 g/ml Sulfuric acid, approximately Ô 1,84 g/ml, diluted + 4.1 4.2 4.3 4.4 © BSI 11-1999 App aratus Ordinary laboratory equipment and A spectrophotometer, suitable for measuring the absorbance of the solution at a wavelength of 500 nm to 520 nm (see ), together with cells of 40 mm and 10 mm optical path length 5.1 4.6 Apparatus for the evolution and absorption of arsine , as shown in Figure NOTE Approximate dimensions are shown in the figure Important parameters are an adequate depth of immersion and sufficient free space around the capillary to allow the bubbles to rise without agglomeration If these conditions are satisfied, variations in the apparatus should be permissible It is essential that the arsine absorption is complete This may be verified initially for a given piece of apparatus by coupling a second absorption vessel in series with the first E N 2 : 995 NOTE The dimensions given are the approximate values only Figure — Arsine e volution and ab so rp tion ap p aratus S amp ling Blank te st Sampling shall be carried out in accordance with With each analytical run, carry out the calibration EURONORM procedure as specified in 7.4 The zero member of the calibration series provides automatic Proce dure compensation for arsenic in the reagents — see 7.4.3 and the note Te st p ortion Weigh, to the nearest 0, 0001 g, a test portion of 0, g NOTE ± 0, 005 g For coarse samples, where the weighing of 0, g may be inconvenient or where a more representative sample is required, a larger portion may be dissolved in the acid- mixture (4 ) After the prolonged heating period and the extraction of the residue in hydrochloric acid (4 ) , an aliquot equivalent to 0, g shall be taken and treated with ml of sulfuric acid (4 ) as specified in 7.3.1 © BSI 1 - 999 EN 021 2:1 995 7.3 Determination 7.3.1 Preparation of the test solution Transfer the test portion (7.1 ) to a 100 ml conical beaker, add 10 ml of hydrochloric-nitric acid mixture (4.5 ), cover the beaker with a watch-glass and digest until solvent action ceases Rinse and remove the watch-glass and heat carefully until all liquid has been evaporated Continue to heat the dried residue at a temperature of 300 °C to 350 °C for a period of about h Cool, add 10 ml of hydrochloric acid (4.3 ) and heat to dissolve the residue Add 10 ml of sulfuric acid (4.4) and heat carefully to remove oxides of nitrogen Continue heating until copious white fumes of sulfur trioxide are evolved Cool, dilute with water to 40 ml, warming if necessary to dissolve the precipitated sulfates 7.3.2 Reduction of arsenic (V) to arsenic (III) Allow the evolution of arsine to proceed for 30 Remove the absorption tube from the evolution apparatus and dilute to the 20 ml mark on the tube with trichloromethane to make up for loss by evaporation Mix the solution thoroughly 7.3.4 Spectrophotometric measurement Carry out the spectrophotometric measurement at the peak wavelength (500 nm to 520 nm, see 4.6) after having set the spectrophotometer (5.1 ) to zero absorption in relation to water Use 40 mm cells for arsenic contents up to 0,02 % and 10 mm cells for contents larger than 0,02 % Control the solution temperature at the time of measurement to be 20 °C ± °C Convert the absorbance readings of the test solution to micrograms of arsenic by reference to the appropriate calibration graph (see 7.4 ) 7.4 Establishment of the calibration graph NOTE It is essential that the calibration graph is established Cool and add in the following order, ml of for each series of samples potassium iodide solution (4.8), ml of ascorbic acid 7.4.1 Preparation of the calibration solutions solution (4.7 ) and ml of tin (II) chloride Weigh 0,1 g portions of iron (4.1 ) into a series solution (4.9 ) Allow to stand for of 100 ml beakers From a burette make additions NOTE In the case of an unalloyed steel, the solution, at this of arsenic standard solution (4.1 ) as shown stage should be virtually colourless Coloration is indicative of incomplete removal of nitric acid Optimum conditions for fuming in Table are best decided in the individual laboratory, with due regard being taken of the temperature variations occurring across hot plate surfaces and to spurting if the temperature rises too fast A final hot plate temperature of approximately 200 °C to 240 °C has been found to be satisfactory Table — Calibration solutions Arsenic standard Arsenic Optical path solution (4.1 ) added length ml 4g mm 0,0 10 and 40 0,5 2,5 40 Transfer the solution to the evolution flask (5.2 ), 1,0 40 rinsing with 10 ml to 20 ml of water Dry the neck of 2,0 10 40 the flask, add a mixture of g of zinc shot and g of 3,0 15 40 zinc pellets (4.2 ) and immediately connect the flask 4,0 20 10 and 40 to the delivery tube by means of the ground glass 8,0 40 10 stopper As evolution commences, immerse the 12,0 60 10 delivery tube into 20 ml of the absorption 16,0 80 10 solution (4.6 ) contained in an absorption tube with a 20,0 ml mark (See the figure.) Continue as described in 7.3.1 , 7.3.2 and 7.3.3 NOTE It is important to avoid crystallization at the tip of the Evolution of arsine and development of the colour 7.3.3 capillary with the danger of blockage and pressure build-up in the apparatus Recommended practice is to lower the delivery tube slowly into the absorption solution (or conversely, if more convenient, to raise the absorption vessel) as evolution commences, so that the inside of the capillary remains dry At the end of the experiment, the bore at the tip of the capillary should be cleaned immediately with a fine wire and rinsed with trichloromethane to prevent adhesion of dried salts A multihole bubbler could be advantageous in minimizing the risk of blocking, but being more difficult to standardize, may increase the risk of arsine carry over NOTE During the experiment there is inevitably a small release of trichloromethane vapour It is recommended that the apparatus is placed in a fume cupboard or is otherwise adequately ventilated © BSI 11-1999 7.4.2 Spectrophotometric measurements 7.4.3 Plotting the calibration graph Carry out the spectrophotometric measurements according to the method described in 7.3.4 after having adjusted the spectrophotometer (5.1 ) to zero absorbance in relation to water Prepare calibration graphs (10 mm and 40 mm cells) by plotting the absorbance readings against micrograms of arsenic in the measuring solution NOTE Using the calibration graphs as described above results in an automatic correction of the arsenic in the blank EN 10212:1995 Expression of results Test report The arsenic content (As), expressed as a percentage The test report shall contain the following by mass, is given by the equation: particulars: As = m m × 00 × 10 = m m a) the method of analysis used by reference to this × 10 European Standard; b) the results obtained; where c) any particular details which may have been m is the value of the mass of the test portion m is the value of the mass of arsenic found Standard or any optional operations which could in the test solution in have had an influence on the result; in g noted during the determination; d) any operations not specified in this European 4g e) all indications necessary for the identification of the sample; f) the laboratory and the date of analysis © BSI 1 - 999 EN 10212:1995 Annex A (informative) Precision data The available data not permit statistical analysis according to ISO 5725:1986 The results obtained show a standard deviation of 0,002 % As at a The method has been tested by analysts of different concentration level of 0,050 % As laboratories on the certified reference materials shown in Table A.1 Table A.1 — Certified reference materials tested Materials Certified As content % 0,007 0,007 EURONORM CRM 077-2 NBS 55e Unalloyed steel Open hearth iron EURONORM CRM 053-1 NBS 82 NBS 4g High purity iron Ni-Cr cast iron Cast iron 0,009 0,009 0,012 BCS 322 CRM 077-1 CRM 039-2 CRM 076-2 BCS 260/3 Unalloyed steel Unalloyed steel Unalloyed steel Unalloyed steel High purity iron 0,012 0,014 0,018 0,022 0,026 EURONORM CRM 082-1 BCS 239-3 NBS 6f Unalloyed steel Unalloyed steel Cast iron 0,029 0,032 0,032 EURONORM CRM 079-1 BCS 453 Unalloyed steel Unalloyed steel 0,051 0,052 EURONORM EURONORM EURONORM © BSI 11-1999 blank BS EN 10212:1996 List of references See national foreword © BSI 1 - 999 BS EN 10212:1996 BSI — British Standards Institution BS I is the indep endent national b ody res p ons ib le for p rep aring Britis h S tandards It p res ents the UK view on s tandards in E urop e and at the international level It is incorp orated b y Royal C harter Revisions Britis h S tandards are up dated b y amendment or revis ion Us ers of Britis h S tandards should make s ure that they p oss es s the latest amendments or editions It is the constant aim of BS I to imp rove the quality of our p roducts and services We would b e grateful if anyone finding an inaccuracy or amb iguity while us ing this Britis h S tandard would inform the S ecretary of the technical committee res p ons ib le, the identity of which can b e found on the inside front cover Tel: 02 89 96 90 00 Fax: 02 89 96 40 BS I offers memb ers an individual up dating s ervice called PLUS which ens ures that s ub s crib ers automatically receive the lates t editions of s tandards Buying standards O rders for all BS I, international and foreign s tandards p ub lications s hould b e addres s ed to C us tomer S ervices Tel: 899 00 Fax: 899 7001 In res p ons e to orders for international standards , it is BS I p olicy to sup p ly the BS I imp lementation of thos e that have b een p ub lis hed as Britis h S tandards, unless otherwis e requested Information on standards BS I p rovides a wide range of information on national, E urop ean and international standards through its Lib rary and its Technical H elp to E xp orters S ervice Various BS I electronic information s ervices are also availab le which give details on all its p roducts and s ervices C ontact the Information C entre Tel: 02 89 96 71 1 Fax: 02 89 96 048 S ub s crib ing memb ers of BS I are kep t up to date with s tandards develop ments and receive sub s tantial discounts on the p urchase p rice of s tandards For details of thes e and other b enefits contact Memb ership Adminis tration Tel: 02 89 96 70 02 Fax: 02 89 96 00 Copyright C op yright s ub s is ts in all BS I p ub lications BS I als o holds the cop yright, in the UK, of the p ub lications of the international s tandardization b odies E xcep t as p ermitted under the C op yright, D es igns and Patents Act 988 no extract may b e rep roduced, s tored in a retrieval s ystem or transmitted in any form or b y any means – electronic, p hotocop ying, recording or otherwis e – without p rior written p ermis s ion from BS I This does not p reclude the free us e, in the cours e of imp lementing the standard, of necess ary details such as s ymb ols, and size, typ e or grade designations If thes e details are to b e used for any other p urp os e than imp lementation then the p rior written p ermiss ion of BS I must b e ob tained If p ermis sion is granted, the terms may include royalty p ayments or a licensing agreement D etails and advice can b e ob tained from the C op yright Manager BS I 89 C his wick H igh Road London W4 4AL Tel: 02 89 96 70