1、BRITISH STANDARD BS 7709-4: 1993 ISO 10136-4: 1993 Analysis of extract solutions of glass Part 4: Method for determination of aluminium oxide by molecular absorption spectrometry UDC 666.11/.18.01.2:543.422:546.623-31BS7709-4:1993 This British Standard, having been prepared under the directionof the
2、 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 90/56737DC ISBN 0 580 22285 3 C
3、ommittees 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 Asso
4、ciation 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 standard
5、, through a subcommittee: Society of Glass Technology Amendments issued since publication Amd. No. Date CommentsBS7709-4:1993 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 R
6、eagents 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 coverBS7709-4:1993 ii BSI 10-1999 National foreword This Part of BS7709 has been prepared under the direction of the Laborator
7、y Apparatus Standards Policy Committee and is identical with ISO10136-4:1993 Glass and glassware Analysis of extract solutions Part4: Determination of aluminium oxide by molecular absorption spectrometry, published by the International Organization for Standardization (ISO). ISO10136-4 has been prep
8、ared 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 molecular absorption spectrometry; Part 2: Method for determination of sodium oxide and po
9、tassium 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) oxide b
10、y 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 Part1:1988 Glasses of the soda-lime-magnesia-silica type and Part3:1988 Glasses of the potass
11、ium 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 r
12、eference 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 835-2:1
13、981 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 glass 3.
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)BS7709-4:1993 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 BritishStandard should indicate that the method of test used is in accordance with BS7709-4:1993. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards
16、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, pagesi toiv, pages1to6, an inside back cover and a back cover. This standard has
17、 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 blankBS7709-4:1993 BSI 10-1999 1 Introduction The amounts of aluminium oxide (Al 2 O 3 ) extracted from most glasses by methods normally used for me
18、asuring the hydrolytic resistance are extremely small, therefore very sensitive analytical methods are needed for its determination. Technical Committee2, Chemical Durability and Analysis, of the International Commission on Glass (ICG), examined the problem (see6 inAnnex A) and decided that the most
19、 widely applicable approach would probably be via a molecular absorption spectrometic method, although flame atomic absorption spectrometry was also studied. A considerable number of reagents are available for producing colour complexes with aluminium but none is particularly outstanding. Three were
20、 selected for the round-robin examination in which eleven laboratories collaborated and they were chromazurol S, eriochrome cyanine and8-hydroxyquinoline. The results obtained suggested that the chromazurol S method was the most satisfactory from an operational point of view and, at the low concentr
21、ations of aluminium oxide expected in extract solutions, is probably as accurate as any other generally available method. In a later investigation, the determination of very low concentrations of aluminium oxide in extract solutions by flame atomic absorption spectrometry was examined. The results c
22、learly indicated that the proposed flame atomic absorption spectrometric method is not suitable for the determination of low concentrations of aluminium oxide in extract solutions. The results of investigations on turbidities, especially in grain test solutions, showed that acidification to dissolve
23、 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 part of ISO10136 specifies an analytical procedure, using molecular absorptio
24、n spectrometry, for measuring the concentrations of aluminium, expressed as its oxide (Al 2 O 3 ), released into extract solutions during hydrochloric resistance test procedures. This part of ISO10136 applies to the analysis of extract solutions obtained from any kind of glass or glassware, includin
25、g laboratory and pharmaceutical ware made, for example, from borosilicate glass (such as borosilicate glass3.3 according to ISO3585), neutral glass, or soda-lime-silica glass as defined in ISO480234, food and drink packaging ware, tableware and kitchenware. The extract solution may be obtained from
26、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 Normative references Th
27、e 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 ISO10136 are encourage
28、d 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 Part2: Burettes for which no waiting time is specified. ISO 648:
29、1977, Laboratory glassware One-mark pipettes. ISO 835-1:1981, Laboratory glassware Graduated pipettes Part1: General requirements. ISO 835-2:1981, Laboratory glassware Graduated pipettes Part2: Pipettes for which no waiting time is specified. ISO 835-3:1981, Laboratory glassware Graduated pipettes P
30、art3: Pipettes for which a waiting time of15s is specified. ISO 1042:1983, Laboratory glassware One-mark volumetric flasks. ISO 3585:1991, Borosilicate glass 3.3 Properties. ISO 3696:1987, Water for analytical laboratory use Specification and test methods. ISO 3819:1985, Laboratory glassware Beakers
31、. ISO 6955:1982, Analytical spectroscopic methods Flame emission, atomic absorption, and atomic fluorescence Vocabulary. BS7709-4:1993 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 obtained from the r
32、eaction 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 stock solution a so
33、lution 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 solutions 3.6 set of
34、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) a technique for det
35、ermining 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 Principle Complexing of
36、 the extract solution to be analysed with chromazurol S. Measurement of the optical density of the resulting solution by means of a molecular absorption spectrometer at545nm using10mm optical cells. 5 Reagents During the analysis, unless otherwise stated, use only reagents of recognized analytical g
37、rade, 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, stating the number of volumes of the conc
38、entrated reagent to be added to a given number of volumes or water. For example, 1+3 means that1volume of the concentrated reagent shall be diluted with3volumes of water. Commercially available standard solutions for colorimetry may be used for the preparation of stock or standard solutions. 5.1 Alu
39、minium (Al), foil. 5.2 Aluminium oxide, stock solution. Transfer 264,7mg of aluminium (5.1), cut into small pieces, to a250ml beaker (6.4) containing5ml of hydrochloric acid (5.9) and5ml of water. Add1drop of copper solution (5.7) to aid dissolution and allow to dissolve with the beaker partially im
40、mersed in a cold water bath. Heat to boiling and boil for1min. Cool, transfer the solution to a500ml one-mark volumetric flask (6.5), make up to the mark with water and mix. 1 ml of this stock solution contains1,0mg of Al 2 O 3 . 5.3 Aluminium oxide, standard solution. Using a one-mark pipette (6.7)
41、, transfer5,00ml of the aluminium oxide stock solution (5.2) to a1000ml one-mark volumetric flask (6.5). Add10ml of hydrochloric acid (5.9.1), make up to the mark with water and mix. 1 ml of this standard solution contains 54g of Al 2 O 3 . 5.4 Ascorbic acid (C 6 H 8 O 6 ), 16g/l solution freshly pr
42、epared immediately before use. 5.5 Chromazurol S (C 23 H 13 Cl 2 Na 3 O 9 S), solution. Dissolve 0,10g of chromazurol S in ethanol (5.8), transfer to a250ml one-mark volumetric flask(6.5), make up to the mark with ethanol andmix. 5.6 Copper (Cu), foil. 5.7 Copper, (Cu 2+ ), 1g/l solution. Transfer10
43、0mg of copper (5.6), cut into small pieces, to a50ml beaker (6.4), add10ml of hydrochloric acid (5.9.1) and heat to dissolve. Cool, transfer to a100ml one-mark volumetric flask(6.5), make up to the mark with water andmix. 5.8 Ethanol (C 2 H 5 OH). 5.9 Hydrochloric acid (HCl), =1,19g/ml.BS7709-4:1993
44、 BSI 10-1999 3 5.9.1 Hydrochloric acid, diluted 1+1. 5.9.2 Hydrochloric acid, diluted 1+24. 5.10 Sodium acetate trihydrate (CH 3 COONa.3H 2 O), buffer solution. Dissolve150g of sodium acetate trihydrate in water, transfer to a1000ml one-mark volumetric flask (6.5), make up to the mark and mix. Trans
45、fer the solution to a stoppered plastics bottle(6.3) for storage. 5.11 Sodium hydroxide, solution, c(NaOH). 0,1mol/l, stored in a plastics bottle (6.3). 6 Apparatus All laboratory glassware, except pipettes and burettes, shall be made of borosilicate glass, preferably of type3.3 complying with the r
46、equirements in ISO3585. Ordinary laboratory apparatus, and 6.1 Molecular absorption spectrophotometer, capable of measuring optical density at545nm. 6.2 Optical cells, 10mm path length. 6.3 Plastics bottles, stoppered, of a suitable capacity e.g.about1000ml. 6.4 Beakers, of a suitable capacity e.g.1
47、00ml, and complying with the requirements in ISO3819. 6.5 One-mark volumetric flasks, of a suitable capacity, and complying with the requirements for class A one-mark volumetric flasks in ISO1042. 6.6 Graduated pipette, of a suitable capacity e.g.20ml, and complying with the requirements for class A
48、 graduated pipettes in ISO835-1, ISO835-2 or ISO835-3. 6.7 One-mark pipettes, of capacity10ml and50ml, and complying with the requirements for class A one-mark pipettes in ISO648. 6.8 Burettes, of a suitable capacity e.g.10ml, and complying with the requirements for class A burettes in ISO385-2. 6.9
49、 Balance, with a discrimination of0,1mg. 6.10 pH-meter, with glass and calomel electrodes, or combined electrodes. 6.11 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 barium sulfate. 7 Sampling and samples The sample for analysis shall be the extra
