1、BRITISH STANDARD BS 7709-2: 1993 ISO 10136-2: 1993 Analysis of extract solutions of glass Part 2: Method for determination of sodium oxide and potassium oxide by flame spectrometric methods UDC 666.11/.18.01.2:543.422:546.32 + .33-31BS7709-2:1993 This British Standard, having been prepared under the
2、 directionof the 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 90/56735 DC ISB
3、N 0 580 22278 0 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 BL
4、WA 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 represented in the draftin
5、g of the standard, through a subcommittee: Society of Glass Technology Amendments issued since publication Amd. No. Date CommentsBS7709-2:1993 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 1
6、4 Principle 2 5 Reagents 2 6 Apparatus 3 7 Sampling and samples 3 8 Procedure 3 9 Expression of results 4 10 Test report 5 Annex A (informative) Bibliography 6 Table 1 Conditions for use of the instruments for measuring sodium (Na) and potassium (K) 5 List of references Inside back coverBS7709-2:199
7、3 ii BSI 10-1999 National foreword This Part of BS7709 has been prepared under the direction of the Laboratory Apparatus Standards Policy Committee and is identical with ISO10136-2:1993 Glass and glassware Analysis of extract solutions Part2: Determination of sodium oxide and potassium oxide by flam
8、e spectrometric methods, published by the International Organization for Standardization (ISO). ISO10136-2 has been 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 determi
9、nation of silicon dioxide by molecular 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 deter
10、mination of aluminium oxide by molecular 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. BS2649 Metho
11、ds for analysis of glass Part1:1988 Glasses of the soda-lime-magnesia-silica type and Part3:1988 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 BS264
12、9. The Technical Committee has reviewed the provisions of ISO385-2, ISO648, ISO835-3 and ISO6955, 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
13、 be 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 BS7709-2:1993. Cross-references International Standard Corresponding British Standard BS 700 Graduated pipettes ISO 835-1:1981 P
14、art 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-mark volumetric flasks (Identical) ISO 3585:1991 BS 2598 Glass plant, pipeline and f
15、ittings Part 1:1991 Specification for properties of borosilicate glass 3.3 (Identical) ISO 3696:1987 BS 3978:1987 Specification for water for laboratory use (Identical)BS7709-2:1993 BSI 10-1999 iii A British Standard does not purport to include all the necessary provisions of a contract. Users of Br
16、itish Standards 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, pages1to6, an inside back cover and a back cover.
17、 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.iv blankBS7709-2:1993 BSI 10-1999 1 Introduction Classifications of glass or glassware, in National or International Standards and in
18、 the various pharmacopoeia, have relied for many years on a titration of extract solutions with a diluted mineral acid. Such solutions may contain not only the alkali metal oxides (sodium and potassium), but also the alkaline earth oxides (calcium and magnesium), which are also titrated by acid. Thu
19、s, the determination is actually of the total alkalinity of the extract solution and this is calculated as the equivalent mass of sodium oxide. In recent years, with the advent of more modern techniques, such as flame spectrometric methods, these techniques have been applied more and more. Therefore
20、, the specific determination of sodium and potassium in extract solutions is possible, and this is of interest for many general investigations on the durability of glasses. The procedure was established and applied to simulated or actual durability extract solutions of glasses in an international co
21、llaborative study conducted by Technical Committee2, Chemical Durability and Analysis, of the International Commission on Glass (ICG). In these round robins, up to21analysts from15laboratories collaborated. The final results of the round robin were that for the very low concentrations in extract sol
22、utions, e.g.from borosilicate glasses, no spectrochemical buffer needs to be added, and that for other aqueous extract solutions the addition of only caesium chloride is sufficient (see 5 in Annex A). The flame spectrometric methods described in this part of ISO10136 are claimed to be satisfactory f
23、or determining both alkali metal oxides in durability extract solutions. The results of investigations on turbidities, 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
24、by using spectroscopic buffer solutions, which are normally strongly acidic, or by addition of acids. 1 Scope This part of ISO10136 specifies the analytical methods of flame spectrometry, using either atomic emission (also in the filter flame spectrometer technique) or atomic absorption spectrometry
25、, for measuring the concentrations of sodium and potassium, expressed as sodium oxide (Na 2 O) and potassium oxide (K 2 O), released into extract solutions during hydrolytic resistance test procedures. This part of ISO10136 applies to the analysis of extract solutions obtained from any kind of glass
26、 or glassware, 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, tableware and kitchenware. The extract solution
27、 may 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
28、Normative 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
29、 ISO10136 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 tim
30、e is specified. 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 glas
31、sware Graduated pipettes Part 3: Pipettes for which a waiting time of 15 s 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 6955:1982,
32、 Analytical spectroscopic methods Flame emission, atomic absorption, and atomic fluorescence Vocabulary. 3 Definitions For the purposes of this part of ISO10136, the following definitions apply.BS7709-2:1993 2 BSI 10-1999 3.1 extract solution the aqueous solution obtained from the reaction of glass
33、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 solution of appropr
34、iate 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 calibration solut
35、ions; set of reference solutions a set of simple or synthetic reference solutions having different analyte concentrations. The zero member is, in principle, the solution having zero concentration of the analyte ISO6955 3.7 flame atomic absorption spectrometry (FAAS) a technique for determining the c
36、oncentration of chemical elements based on the measurement of the absorption of characteristic electromagnetic radiation in a vapour phase in a flame 3.8 flame emission spectrometry (FES) a method of determining chemical elements based on the measurement of the intensity of characteristic electromag
37、netic radiation emitted by atoms or molecules in a flame ISO6955 3.9 filter flame spectrometry (Filter FES) a method equivalent to flame emission spectrometry (FES) (3.8) using filters for selection of the detection lines 3.10 spectrochemical buffer solution a solution of a substance or substances a
38、dded 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 which the relationship between absorption (or emission) and concentratio
39、n is linear 4 Principle Spraying of the extract solution to be analysed into the flame of the burner of an emission or absorption spectrometer, if necessary with the addition of a spectrochemical buffer solution, or into the flame of a filter flame spectrometer without this addition. For FES and FAA
40、S, for the determination of sodium and potassium using their lines at589,0nm and766,5nm respectively, using a set of reference solutions. For a flame filter spectrometer, using the special filters for the determination of sodium and potassium 5 Reagents During the analysis, unless otherwise stated,
41、use only reagents of recognized analytical grade, and grade1or grade2 water as 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 ra
42、tio, stating the number of volumes of the concentrated reagent to be added to a given number of volumes or water. For example, 1+3means that1volume of the concentrated reagent shall be diluted with3 volumes of water. Commercially available standard solutions for spectrometry may be used for the prep
43、aration of stock or standard solutions. 5.1 Hydrochloric acid (HCl), = 1,19 g/ml. 5.1.1 Hydrochloric acid, diluted1+1. 5.1.2 Hydrochloric acid, diluted1+12. 5.2 Caesium chloride (CsCl) 5.3 Spectrochemical buffer solution, caesium chloride solution. Dissolve40g of caesium chloride (5.2) in water, add
44、100ml of the hydrochloric acid (5.1) and transfer to a1000ml one-mark volumetric flask(6.4). Dilute to the mark with water and mix. Store the spectrochemical buffer solution in a pre-treated borosilicate glass bottle (6.3).BS7709-2:1993 BSI 10-1999 3 5.4 Sodium chloride (NaCl) Dry for at least1h at1
45、10 C, allow to cool and store in a desiccator. 5.5 Potassium chloride (KCl) Dry for at least1h at110 C, allow to cool and store in a desiccator. 5.6 Sodium oxide, stock solution Use commercially available standard solution or prepare as follows. Dissolve1,8858g of the sodium chloride (5.4) in water
46、in a1000ml one-mark volumetric flask (6.4), make up to the mark and mix. Store this solution in a pre-treated borosilicate glass bottle (6.3). 1ml of this stock solution contains1mg of Na 2 O. 5.7 Potassium oxide, stock solution. Use commercially available standard solutions, or prepare as follows.
47、Dissolve1,5830g of the potassium chloride (5.5) in water in a1000ml one-mark volumetric flask (6.4), make up to the mark and mix. Store this solution in a pre-treated borosilicate glass bottle (6.3). 1mg of this solution contains1mg of K 2 O. 5.8 Sodium oxide, and potassium oxide, standard solutions
48、. Preliminary measurements of the extract solution shall show which range of concentration of both oxides is to be expected. According to the analytical task, prepare standard solutions by diluting appropriate volumes of the stock solutions (5.6 and5.7) such that, for instance, concentrations of1004
49、g Na 2 O and1004g K 2 O per millilitre are obtained, or, since K 2 O is very often released in only small amounts, 1004g Na 2 O and104g K 2 O per millilitre are obtained. Store these standard solutions in pre-treated borosilicate glass bottles (6.3). 1000ml of each standard solutions shall contain5ml of hydrochloric acid (5.1.1). 6 Apparatus All laboratory glassware, except pipettes and burettes, shall be made of borosilicate glass, preferably of type3.3complying with the requirements in ISO3585. Ordinary labora
