1、BRITISH STANDARD BS 7709-6: 1993 ISO 10136-6: 1993 Analysis of extract solutions of glass Part 6: Method for determination of boron(III) oxide by molecular absorption spectrometry UDC 666.11/.18.01.2:543.422:546.273-31BS7709-6:1993 This British Standard, having been prepared under the directionof th
2、e Laboratory Apparatus Standards Policy Committee, was published underthe authority of the Standards Board and comes intoeffect on 15September1993 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference LBC/36 Draft for comment 90/56739 DC ISBN 0 580 22289 6
3、 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 for Science Education BLWA Ltd. (The As
4、sociation 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 represented in the drafting of the standa
5、rd, through a subcommittee: Society of Glass Technology Amendments issued since publication Amd. No. Date CommentsBS7709-6:1993 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii Introduction 1 1 Scope 1 2 Normative references 1 3 Definitions 2 4 Principle 2 5
6、 Reagents 2 6 Apparatus 3 7 Sampling and samples 3 8 Procedure 3 9 Expression of results 4 10 Test report 4 Annex A (informative) Bibliography 5 List of references Inside back coverBS7709-6:1993 ii BSI 10-1999 National foreword This Part of BS7709 has been prepared under the direction of the Laborat
7、ory Apparatus Standards Policy Committee and is identical with ISO10136-6:1993 Glass and glassware Analysis of extract solutions Part 6: Determination of boron(III) oxide by molecular absorption spectrometry, published by the International Organization for Standardization (ISO). ISO10136-6 has been
8、prepared by Subcommittee5 of Technical Committee ISO/TC48, with the active participation and approval of the UK. BS7709 is published in six Parts as follows: Part 1: Method for determination of silicon dioxide by molecular absorption spectrometry; Part 2: Method for determination of sodium oxide and
9、 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 molecular absorption spectrometry; Part 5: Method for determination of iron(III) oxid
10、e by molecular absorption spectrometry and flame atomic absorption spectrometry; Part 6: Method for determination of boron(III) oxide by molecular absorption spectrometry. BS2649 Methods for analysis of glass Part1:1988 Glasses of the soda-lime-magnesia-silica type and Part3:1988 Glasses of the pota
11、ssium 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. The Technical Committee has reviewed the provisions of ISO385-2, ISO648, ISO835-3 and ISO6955, to which normative
12、 reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. Cross-references International Standard Corresponding British Standard ISO 835-1:1981 BS 700 Graduated pipettes Part 1:1982 Specification for general requirements (Identical) ISO 835-2
13、:1981 Part 2:1982 Specification for pipettes for which no waiting time is specified (Identical) ISO 1042:1983 BS 1792:1982 Specification for one-mark volumetric flasks (Identical) ISO 3585:1991 BS 2598 Glass plant, pipeline and fittings Part 1:1991 Specification for properties of borosilicate glass3
14、.3 (Identical) ISO 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)BS7709-6:1993 BSI 10-1999 iii This British Standard describes a method of test only and should not be
15、 used or quoted as a specification defining limits of performance. Reference to this British Standard should indicate that the method of test used is in accordance with BS7709-6:1993. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standard
16、s are responsible for their correct application. Compliance with a British Standard does 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 stand
17、ard 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.iv blankBS7709-6:1993 BSI 10-1999 1 Introduction The amounts of boron(III) oxide (B 2 O 3 ) extracted from glass and glassware during hydrolytic
18、 resistance tests are normally very small, even from heat-resisting borosilicate glass3.3 used for making laboratory ware. Therefore, neither macro-titration methods nor flame atomic absorption spectrometry are suitable for its determination, so recourse shall be made to colorimetric techniques usin
19、g measurement by molecular absorption spectrometry. Boron(III) oxide forms coloured complexes with a number of organic reagents, but those most commonly used are curcumin, 1,1-dianthrimide, carminic acid, quinalizarin, and for some years azomethine H. Technical Committee2, Chemical Durability and An
20、alysis, of the International Commission on Glass (ICG), examined the determination of boron(III) oxide using all of these reagents (see 7 inAnnex A) and recommended the procedure using azomethine H, after consideration of all of the results and comments received. In a round-robin examination involvi
21、ng eleven laboratories, the participants were provided with a homogeneous extract solution obtained from ordinary borosilicate glass containers using an autoclave process according to ISO4802. The results obtained were considered to be very satisfactory. The results of investigations on turbidities,
22、 especially in grain test solutions, showed that acidification to dissolve possible hydroxides and/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 par
23、t of ISO10136 specifies an analytical procedure, using molecular absorption spectrometry, for measuring the concentrations of boron, expressed as its oxide (B 2 O 3 ), released into extract solutions during hydrolytic resistance test procedures. This part of ISO10136 applies to the analysis of extra
24、ct solutions obtained from any kind of glass or glassware, including laboratory and pharmaceutical ware made, for example, from borosilicate glass (such as borosilicate glass3.3 according to ISO3585), or neutral glass as defined in ISO4802 34 , tableware and kitchenware. The extract solution may be
25、obtained from glass articles, for example according to ISO4802, or from glass as material, for example when tested according to ISO7191 or ISO 7202. In addition, it may be applied to the extract solutions produced by any method for measuring the hydrolytic resistance of glass or glassware. 2 Normati
26、ve 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 ISO101
27、36 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 sp
28、ecified. 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 G
29、raduated pipettes Part 3: Pipettes for which a waiting time of15s is specified. ISO 1042:1983, Laboratory glassware One-mark volumetric flasks. ISO 3585:1991, Borosilicate glass3.3 Properties. ISO 3696:1987, Water for analytical laboratory use Specification and test methods. ISO 3819:1985, Laborator
30、y glassware Beakers. ISO 6955:1982, Analytical spectroscopic methods Flame emission, atomic absorption, and atomic fluorescence Vocabulary. BS7709-6:1993 2 BSI 10-1999 3 Definitions For the purposes of this part of ISO10136, the following definitions apply. 3.1 extract solution the aqueous solution
31、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 solution 3.3 analyte the element or constituent to be determined 3.4
32、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 concentration suitable for the preparation of reference or calibration so
33、lutions 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 concentration of the analyte ISO6955 3.7 molecular absorption spectrometry (MAS)
34、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 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 4 Prin
35、ciple Complexing of the boron in the extract solution to be analysed with azomethine H. Measurement of the optical density of the resulting colour complex by means of a molecular absorption spectrometer at415nm using20mm optical cells. 5 Reagents During the analysis, unless otherwise stated, use onl
36、y reagents of recognized analytical grade, and grade1 or grade2 water specified in ISO3696. When acids and 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, stat
37、ing the number of volumes of the concentrated reagent to be added to a given number of volumes or water. For example, 1 + 3 means that1 volume of the concentrated reagent shall be diluted with3 volumes of water. Commercially available standard solutions for colorimetry may be used for the preparatio
38、n of stock or standard solutions. 5.1 Boric acid (H 3 BO 3 ). 5.2 Boron(III) oxide, stock solution. Dissolve1,776g of boric acid (5.1) in water contained in a1000ml one-mark volumetric flask(6.5), make up to the mark and mix. Transfer to a boron-free glass or plastics bottle(6.3) for storage. 1 ml o
39、f this stock solution contains1004g ofB 2 O 3 . 5.3 Boron(III) oxide, standard solution. Using a one-mark pipette (6.8), transfer5ml of the boron(III) oxide stock solution (5.2) to a500ml one-mark volumetric flask (6.5), make up to the mark with water and mix. This solution shall be freshly prepared
40、 immediately before use. 1 ml of this standard solution contains104g of B 2 O 3 . 5.4 Ascorbic acid (C 6 H 8 O 6 ). 5.5 Azomethine H (C 17 H 12 NNaO 8 S 2 ), solution. Dissolve1g of azomethine H and3g of ascorbic acid (5.4) in100ml of water. Filter the solution through a close filter paper and store
41、 in the dark. Discard after one week. 5.6 Acetic acid (CH 3 COOH), glacial, = 1,05g/ml. 5.7 Ammonium acetate (CH 3 COONH 4 ). 5.8 Ammonium hydroxide (NH 4 OH), = 0,88g/ml. 5.9 Buffer solution Dilute80ml of acetic acid (5.6) to100ml with water and add50g of ammonium acetate (5.7). After dissolving it
42、, adjust the pH of the solution to4,5 using the pH meter (6.11), and either acetic acid(5.6) or ammonium hydroxide (5.8). Store in a plastics bottle (6.3).BS7709-6:1993 BSI 10-1999 3 5.10 Ethylene diaminetetraacetic acid disodium salt (EDTA) (C 10 H 14 N 2 Na 2 O 8 .2H 2 O). 5.11 Citric acid (C 6 H
43、8 O 7 .H 2 O). 5.12 Sodium hydroxide, solution, c(NaOH) . 5mol/l, stored in a plastics bottle (6.3). 5.13 Sodium hydroxide, solution, c(NaOH) . 0,1mol/l. 5.14 Hydrochloric acid (HCl), = 1,19g/ml. 5.15 Hydrochloric acid, diluted1+24. 5.16 Screening solution Dissolve20g of the EDTA (5.10) and10g of ci
44、tric acid (5.11) in450ml of water by the progressive addition of sodium hydroxide solution (5.12) until the pH of the solution is4.5 using the pH-meter(6.11). Transfer the solution to the500ml one-mark volumetric flask (6.5), make up to the mark and mix. 6 Apparatus All laboratory glassware, except
45、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 at415nm. 6.2 Optical cells, of suitable path length, e.g.
46、 20mm. 6.3 Bottles made of boron-free glass or plastics, stoppered, of a suitable capacity. 6.4 Beaker, of capacity100ml, and complying with the requirements in ISO3819. 6.5 One-mark volumetric flasks, of a suitable capacity e.g. of500ml and1000ml, and complying with the requirements for class A one
47、-mark volumetric flasks in ISO1042. 6.6 One-mark volumetric flasks, made of silica glass or from suitable plastics, of capacity25ml, and complying with the requirements for class A one-mark volumetric flasks in ISO1042. 6.7 Graduated pipette, of capacity5ml, and complying with the requirements for c
48、lass A graduated pipettes in ISO835-1, ISO835-2 or ISO835-3. 6.8 One-mark pipette, of suitable capacity e.g. 5ml or50ml, and complying with the requirements for class A one-mark pipettes in ISO648. 6.9 Burettes, of a suitable capacity e.g. of10ml, and complying with the requirements for class A bure
49、ttes in ISO385-2. 6.10 Balance, with a discrimination of0,1mg. 6.11 pH-meter, with glass and calomel electrodes, or combined electrodes. 6.12 Magnetic stirrer, with a plastic coated rod. 6.13 Filter papers, of the ashless type washed twice with acid, and designated as follows: “open” or “coarse” will have a porosity generally used for filtering aluminium hydroxide; “medium” will have a porosity generally used for filtering calcium oxalate; “close” or “fine” will have a porosity generally used for filtering bari
