BS 7709-5-1993 Analysis of extract solutions of glass - Method for determination of iron (III) oxide by molecular absorption spectrometry and flame atomic absorption spectrometry《玻.pdf

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1、BRITISH STANDARD BS 7709-5: 1993 ISO 10136-5: 1993 Analysis of extract solutions of glass Part 5: Method for determination of iron(III) oxide by molecular absorption spectrometry and flame atomic absorption spectrometry UDC 666.11/.18.01.2:543.422:546.72-31BS7709-5:1993 This British Standard, having

2、 been prepared under the directionof the Laboratory Apparatus Standards Policy Committee, was published underthe authority of the Standards Board and comes intoeffect on 15 September1993 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference LBC/36 Draft fo

3、r comment 90/56738 DC ISBN 0 580 22288 8 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Laboratory Apparatus Standards Policy Committee (LBC/-) to Technical Committee LBC/36, upon which the following bodies were represented: Association

4、 for Science Education BLWA Ltd. (The Association of the Laboratory Supply Industry) British Glass Manufacturers Confederation CLEAPSS School Science Service Department of Trade and Industry (Laboratory of the Government Chemist) Institute of Medical Laboratory Sciences The following body was also r

5、epresented in the drafting of the standard, through a subcommittee: Society of Glass Technology Amendments issued since publication Amd. No. Date CommentsBS7709-5:1993 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 Normative refe

6、rences 1 3 Definitions 2 4 Principle 2 5 Reagents 2 6 Apparatus 3 7 Sampling and samples 3 8 Procedure 4 9 Expression of results 5 10 Test report 5 Annex A (informative) Bibliography 6 List of references Inside back coverBS7709-5:1993 ii BSI 10-1999 National foreword This Part of BS 7709 has been pr

7、epared under the direction of the Laboratory Apparatus Standards Policy Committee and is identical with ISO10136-5:1993 Glass and glassware Analysis of extract solutions Part 5: Determination of iron(III) oxide by molecular absorption spectrometry and flame atomic absorption spectrometry, published

8、by the International Organization for Standardization (ISO). ISO10136-5 has been prepared by Subcommittee5 of Technical Committee ISO/TC48, with the active participation and approval of the UK. BS 7709 is published in six Parts as follows: Part 1: Method for determination of silicon dioxide by molec

9、ular absorption spectrometry; Part 2: Method for determination of sodium oxide and potassium oxide by flame spectrometric methods; Part 3: Method for determination of calcium oxide and magnesium oxide by flame atomic absorption spectrometry; Part 4: Method for determination of aluminium oxide by mol

10、ecular absorption spectrometry; Part 5: Method for determination of iron(III) oxide by molecular absorption spectrometry and flame atomic absorption spectrometry; Part 6: Method for determination of boron(III) oxide by molecular absorption spectrometry. BS 2649 Methods for analysis of glass Part 1:1

11、988 Glasses of the soda-lime-magnesia-silica type and Part 3:1988 Glasses of the potassium oxide-lead oxide-silica type describe methods of determination primarily of the gravimetric type. The methods given in BS7709 should be considered complementary to those of BS2649. Cross-references Internation

12、al Standard Corresponding British Standard ISO 835-1:1981 BS 700 Graduated pipettes Part 1:1982 Specification for general requirements (Identical) ISO 835-2:1981 Part 2:1982 Specification for pipettes for which no waiting time is specified (Identical) ISO 1042:1983 BS 1792:1982 Specification for one

13、-mark volumetric flasks (Identical) ISO 1773:1976 BS 2734:1984 Specification for boiling flasks (narrow-necked), conical, flat bottom and round bottom (Identical) ISO 3585:1991 BS 2598 Glass plant, pipeline and fittings Part 1:1991 Specification for properties of borosilicate glass 3.3 (Identical) I

14、SO 3696:1987 BS 3978:1987 Specification for water for laboratory use (Identical) ISO 3819:1985 BS 6523:1984 Specification for glass beakers for laboratory use (Technically equivalent)BS7709-5:1993 BSI 10-1999 iii The Technical Committee has reviewed the provisions of ISO385-2, ISO648, ISO835-3 and I

15、SO6955, to which normative reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. This British Standard describes a method of test only and should not be used or quoted as a specification defining limits of performance. Reference to this Br

16、itish Standard should indicate that the method of test used is in accordance with BS7709-5:1993. 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. Compliance with a British Standard doe

17、s not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. Thi

18、s will be indicated in the amendment table on the inside front cover.iv blankBS7709-5:1993 BSI 10-1999 1 Introduction All silicate glasses contain some iron, although in very low concentrations, and in certain usages some of this iron can be released into the contents of a glass container. There may

19、 be serious consequences, for instance when solutions are sterilized by autoclaving after they have been poured into a container, or when solutions are stored (even at ambient temperatures) for long periods of time. Iron may be released into the extract solutions produced during hydrolytic resistanc

20、e tests and, because the concentration will be very low, a very sensitive test method is required for its determination. Technical Committee 2, Chemical Durability and Analysis, of the International Commission on Glass (ICG), investigated the problem (see 6 inAnnex A) and considered flame-emission,

21、flame atomic absorption and two molecular absorption spectrometric methods, using ortho-phenanthroline and bathophenanthroline. As a result of these deliberations, it was considered that the bathophenanthroline method probably offered the greatest sensitivity and freedom from interferences. Nine lab

22、oratories participated in the round-robin study to develop recommended procedures using both molecular absorption and flame atomic absorption spectrometry. The results of investigations on turbidities, especially in grain test solutions, showed that acidification to dissolve possible hydroxides and/

23、or carbonates is necessary prior to the analytical determination. This is achieved by using spectroscopic buffer solutions, which are normally strongly acidic, or by addition of acids. 1 Scope This part of ISO 10136 specifies an analytical procedure, using molecular absorption spectrometry and flame

24、 atomic absorption spectrometry, for measuring the concentrations of iron, expressed as iron(III) oxide (Fe 2 O 3 ), released into extract solutions during hydrolytic resistance test procedures. This part of ISO 10136 applies to the analysis of extract solutions obtained from any kind of glass or gl

25、assware, including laboratory and pharmaceutical ware made, for example, from borosilicate glass (such as borosilicate glass3.3according to ISO3585), neutral glass, or soda-lime-silica glass as defined in ISO480234, food and drink packaging ware, table-ware and kitchenware. The extract solution may

26、be obtained from glass articles, for example according to ISO4802 or from glass as material, for example when tested according to ISO7191 or ISO7202. In addition, it may be applied to the extract solutions produced by any method for measuring the hydrolytic resistance of glass or glassware. 2 Normat

27、ive references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO10136. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO10

28、136 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 385-2:1984, Laboratory glassware Burettes Part 2: Burettes for which no waiting time is s

29、pecified. ISO 648:1977, Laboratory glassware One-mark pipettes. ISO 835-1:1981, Laboratory glassware Graduated pipettes Part 1: General requirements. ISO 835-2:1981, Laboratory glassware Graduated pipettes Part 2: Pipettes for which no waiting time is specified. ISO 835-3:1981, Laboratory glassware

30、Graduated pipettes Part 3: Pipettes for which a waiting time of15s is specified. ISO 1042:1983, Laboratory glassware One-mark volumetric flasks. ISO 1773:1976, Laboratory glassware Boiling flasks (narrow-necked). ISO 3585:1991, Borosilicate glass 3.3 Properties. ISO 3696:1987, Water for analytical l

31、aboratory use Specification and test methods. ISO 3819:1985, Laboratory glassware Beakers. ISO 6955:1982, Analytical spectroscopic methods Flame emission, atomic absorption, and atomic fluorescence Vocabulary. BS7709-5:1993 2 BSI 10-1999 3 Definitions For the purposes of this part of ISO10136, the f

32、ollowing definitions apply. 3.1 extract solution the aqueous solution obtained from the reaction of glass with water under specific conditions 3.2 sample measuring solution the solution actually used for measuring the concentration of the analyte. It may be the undiluted, diluted or modified extract

33、 solution 3.3 analyte the element or constituent to be determined 3.4 stock solution a solution of appropriate composition containing the analyte, expressed as its oxide, in a known but high concentration 3.5 standard solution a solution containing the analyte, expressed as its oxide, in a known con

34、centration suitable for the preparation of reference or calibration solutions 3.6 set of calibration solutions; set of reference solutions a set of simple or synthetic reference solutions having different analyte concentrations. The zero member is, in principle, the solutions having zero concentrati

35、on of the analyte ISO6955 3.7 molecular absorption spectrometry (MAS) a technique for determining the concentration of an analyte in solution by measuring the optical density of a colour complex of the analyte 3.8 flame atomic absorption spectrometry (FAAS) a technique for determining the concentrat

36、ion of chemical elements based on the measurement of the absorption of characteristic electromagnetic radiation in a vapour phase in a flame 3.9 blank test solution a solution prepared in the same way as the sample measuring solution but so that it does not contain the analyte to be determined 3.10

37、spectrochemical buffer solution a solution of a substance or substances added to the sample measuring solution and to the reference solutions in order to reduce interferences during flame spectrometric measurements 3.11 optimum working range the range of concentrations of an analyte in solution over

38、 which the relationship between absorption (or emission) and concentration is linear 4 Principle 4.1 Determination of iron by molecular absorption spectrometry Reduction of the iron in the extract solution to be analysed to the iron(II) state by adding ascorbic acid. Addition of bathophenanthroline

39、and buffering of the solution to pH4 to6. Then, extraction of the coloured iron complex into chloroform. Measurement of the optical density by means of a molecular absorption spectrometer at533nm using40mm optical cells. Determination of the concentration of iron from the calibration graph. 4.2 Dete

40、rmination of iron by flame atomic absorption spectrometry Evaporation of a portion of the extract solution to be analysed with hydrofluoric and perchloric acids and dissolution of the residue in hydrochloric acid solution. Spraying the solution into an air/acetylene flame and measuring the absorptio

41、n using a flame atomic absorption spectrometer at248,3nm. Determination of the concentration of iron from the calibration graph. 5 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical grade, and grade1 or grade2 water specified in ISO3696. When acids and

42、ammonium hydroxide are specified only by name or chemical formula, the concentrated reagent is intended. The concentrations of diluted acids or ammonium hydroxide are specified as a ratio, stating the number of volumes of the concentrated reagent to be added to a given number of volumes or water. Fo

43、r example,1+3means that1volume of the concentrated reagent shall be diluted with3 volumes of water. Commercially available standard solutions for colorimetry or atomic absorption spectrometry may be used for the preparation of stock or standard solutions.BS7709-5:1993 BSI 10-1999 3 5.1 Ammonium hydr

44、oxide, c(NH 3 ) or c(NH 4 OH) . 5 mol/l. 5.2 Ammonium iron(II) sulfate, (NH 4 ) 2 Fe(SO 4 ) 2 .6H 2 O. 5.3 Ascorbic acid (C 6 H 8 O 6 ) 100 g/l solution, freshly prepared. 5.4 Bathophenanthroline (4,7-diphenyl-1,10-phenanthroline), solution, c(C 24 H 16 N 2 ) = 0,001mol/l. 5.5 Chloroform (CHCl 3 ).

45、5.6 Ethanol (C 2 H 5 OH). 5.7 Hydrochloric acid (HCl), = 1,19 g/ml. 5.8 Hydrochloric acid, diluted 1+ 24. 5.9 Perchloric acid (HClO 4 ), 600 g/l solution. 5.10 Sodium acetate trihydrate (CH 3 COONa.3H 2 O). 5.11 Iron, stock solution. Dissolve0,4911g of ammonium iron(II) sulfate(5.2) in water and add

46、10ml of hydrochloric acid (5.7). Transfer the solution to a1000ml one-mark volumetric flask (6.6), make up to the mark and mix. 1 ml of this stock solution contains1004g of Fe 2 O 3 . 5.12 Iron, standard solution, for MAS. Using a one-mark pipette (6.9), transfer10ml of the iron stock solution (5.11

47、) to a1000ml one-mark volumetric flask (6.6), make up to the mark with water and mix. The solution shall be prepared immediately before use. 1 ml of this standard solution contains1,04g of Fe 2 O 3 . 5.13 Iron, standard solution, for FAAS. Using a one-mark pipette (6.9), transfer100ml of the iron st

48、ock solution (5.11) to a1000ml one-mark volumetric flask (6.6), make up to the mark with water and mix. 1 ml of this standard solution contains104g of Fe 2 O 3 . 5.14 Butan-1-Ol CH 3 (CH 2 ) 3 OH. 5.15 Lanthanum oxide (La 2 O 3 ). 5.16 Spectrochemical buffer solution Transfer 11,7g of lanthanum oxid

49、e (5.15) to a250ml beaker (6.4), add100ml of hydrochloric acid (5.7) and dissolve while heating gently. Cool, transfer to a1000ml one-mark volumetric flask(6.6), make up to the mark with water and mix. 6 Apparatus All laboratory glassware, except pipettes and burettes, shall be made of borosilicate glass, preferably of type 3.3. complying with the requirements in ISO3585. Ordinary laboratory apparatus, and 6.1 Molecular absorption spectrophotometer, capable of measuring optical density at533nm. 6.2 Optical cel