1、BRITISH STANDARD CONFIRMED AUGUST 1991 BS 3900-B7: 1986 ISO 3856-2: 1984 Methods of test for paints Part B7: Determination of “soluble” antimony content ISO title: Paints and varnishes Determination of “soluble” metal content Part 2: Determination of antimony content Flame atomic absorption spectrom
2、etric method and RhodamineB spectrophotometric method It is recommended that this Part be read in conjunction with the general information in the Introduction to BS3900, issued separately. UDC 667.61:620.1BS3900-B7:1986 This British Standard, having been prepared under the directionof the Pigments,
3、Paintsand Varnishes StandardsCommittee, was published under the authority ofthe Board of BSI and comes intoeffect on 31 January 1986 BSI 10-1999 The Committees responsible for this British Standard are shown inBS3900: Introduction. The following BSI references relate to the work on this standard: Co
4、mmittee reference PVC/10 Draft for comment 78/51513 DC ISBN 0 580 14946 3 Amendments issued since publication Amd. No. Date of issue CommentsBS3900-B7:1986 BSI 10-1999 i Contents Page National foreword ii 0 Introduction 1 1 Scope and field of application 1 2 References 1 3 Flame atomic absorption sp
5、ectrometric method 1 4 Rhodamine B spectrophotometric method 3 5 Test report 6 Publications referred to Inside back coverBS3900-B7:1986 ii BSI 10-1999 National foreword This Part of BS3900 has been prepared under the direction of the Pigments, Paints and Varnishes Standards Committee. It is identica
6、l with ISO3856-2:1984 “Paints and varnishes Determination of “soluble” metal content” Part2“Determination of antimony content Flame atomic absorption spectrometric method and Rhodamine B spectrophotometric method” published by the International Organization for Standardization (ISO). It is assumed i
7、n the drafting of this standard that it will be used and applied by those who are appropriately qualified and experienced. The procedures described in this standard are intended to be carried out by suitably trained and/or supervised personnel. The substances and procedures described may be injuriou
8、s to health if inadequate precautions are taken. This standard refers only to its technical suitability and does not absolve the user from statutory obligations relating to health and safety. Terminology and conventions. The text of the International Standard has been approved as suitable for public
9、ation as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards, it is current practice to use a full poin
10、t on the baseline as the decimal marker. In British Standards it is current practice to use the symbol “L” for litre rather than “l”, and to use the spelling “sulphur”, etc., instead of “sulfur”, etc. Wherever the words “International Standard” and “part of ISO3856” appear, referring to this standar
11、d, they should be read as “British Standard” and “Part of BS3900” respectively, and wherever the identification “ISO3856-2” appears, it should be read as “BS3900-B7”. The Technical Committee has reviewed the provisions of ISO385-1:1984, and ISO648:1977 to which reference is made in the text, and has
12、 decided that they are acceptable for use in conjunction with this standard. ISO385-1 is related to BS846 “Specification for burettes” and ISO648 is related to BS1583 “One-mark pipettes”. The Technical Committee has reviewed the proposed provisions of ISO3696 to which reference is made in3.2 and4.2
13、and has decided that they are acceptable for use in conjunction with this standard. ISO3696 is related to BS3978 “Water for laboratory use”. Cross-references International Standards Corresponding British Standards ISO 1042:1983 BS 1792:1982 Specification for one-mark volumetric flasks (Identical) IS
14、O 4800:1977 BS 2021:1980 Specification for separating and dropping funnels for laboratory use (Identical) ISO 6713:1984 BS 3900 Methods of test for paints Part B5:1986 Preparation of acid extracts from liquid paints or coating powders Identical)BS3900-B7:1986 BSI 10-1999 iii ISO3856, to which refere
15、nce is made in clause0, is published in a number of Parts of BS3900. At the time of publication of this standard, the relationship between other Parts of BS3900 and Parts of ISO3856 was as follows: Additional information. With reference to the method in clause4, since publication of the ISO standard
16、 it has been reported that Rhodamine B may be a carcinogen. If this method is used precautions should be taken to avoid contact with this reagent or solutions containing it. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are resp
17、onsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Part of ISO 3856 Corresponding Part of BS 3900 BS 3900 Methods of test for paints ISO 3856-1:1984 Part B6:1986 Determination of “soluble” lead content a (Identical) IS
18、O 3856-3:1984 Part B8:1986 Determination of “soluble” barium content (Identical) ISO 3856-4:1984 Part B9:1986 Determination of “soluble” cadmium content (Identical) ISO 3856-5:1984 Part B10:1986 Determination of hexavalent chromium content of solid matter (Identical) ISO 3856-6:1984 Part B11:1986 De
19、termination of total chromium content of liquid matter (Identical) ISO 3856-7:1984 Part B12:1986 Determination of “soluble” mercury content (Identical) a Attention is drawn to a similar standard, BS3900-B3 “Determination of “soluble” lead in the solidmatter in liquid paints: method for use in conjun
20、ction with The Control of Lead at Work Regulations,1980 (S.I.1980 No.1248)”. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages1to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendment
21、s incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS3900-B7:1986 BSI 10-1999 1 0 Introduction This International Standard is a part of ISO3856, Paints and varnishes Determination of “soluble” metal content. 1 Scope and field of application This part of I
22、SO3856 describes two methods for the determination of the antimony content of the test solutions prepared according to ISO6713 or other suitable International Standards. The methods are applicable to paints having “soluble” antimony contents in the range of about0,05 to5% (m/m). The flame atomic abs
23、orption spectrometric (AAS) method (clause3) should be used as the referee method in cases of dispute. Other methods can be used by agreement between the interested parties. If a spectrophotometric method is agreed, the Rhodamine B spectrophotometric method (clause4) should be used. 2 References ISO
24、 385-1, Laboratory glassware Burettes Part1: General requirements 1) . ISO 648, Laboratory glassware One-mark pipettes. ISO 1042, Laboratory glassware One-mark volumetric flasks. ISO 3696, Water for laboratory use Specifications 2) . ISO 4800, Laboratory glassware Separating funnels and dropping fun
25、nels. ISO 6713, Paints and varnishes Preparation of acid extracts from paints in liquid or powder form. 3 Flame atomic absorption spectrometric method 3.1 Principle Aspiration of the test solution into an acetylene/air flame. Measurement of the absorption of the selected spectral line, emitted by an
26、 antimony hollow-cathode or antimony discharge lamp, in the region of217,6nm (see also3.5). 3.2 Reagents and materials During the analysis, use only reagents of recognized analytical grade and only water of at least grade3 purity according to ISO3696. 3.2.1 Hydrochloric acid, approximately 37% (m/m)
27、 ( approximately 1,18g/ml). 3.2.2 Hydrochloric acid, c(HCl) = 1mol/l. 3.2.3 Acetylene, commercial grade, in a steel cylinder. 3.2.4 Compressed air 3.2.5 Antimony, standard stock solution containing1g of Sb per litre. Weigh, to the nearest 0,1mg, 119,7mg of dried antimony trioxide, dissolve in 40ml o
28、f the hydrochloric acid (3.2.1) in a 100ml one-mark volumetric flask, dilute to the mark with water and mix well. 1ml of this standard stock solution contains 1mg ofSb. 3.2.6 Antimony, standard solution containing100mg of Sb per litre. Prepare this solution on the day of use. Pipette 10ml of the sta
29、ndard stock solution (3.2.5) into a 100ml one-mark volumetric flask, dilute to the mark with the hydrochloric acid (3.2.2) and mix well. 1ml of this standard solution contains 1004g of Sb. 3.3 Apparatus Ordinary laboratory apparatus and 3.3.1 Flame atomic absorption spectrometer, suitable for measur
30、ements at a wavelength of217,6nm and fitted with a burner fed with acetylene and air. 3.3.2 Antimony hollow-cathode lamp or antimony discharge lamp 3.3.3 Burette, of capacity 50ml, complying with the requirements of ISO385-1. 3.3.4 One-mark volumetric flasks, of capacity100ml, complying with the req
31、uirements of ISO1042. 3.4 Procedure 3.4.1 Preparation of the calibration graph 3.4.1.1 Preparation of the standard matching solutions Prepare these solutions on the day of use. Into a series of five 100ml one-mark volumetric flasks (3.3.4), introduce from the burette (3.3.3), respectively, the volum
32、es of the standard antimony solution (3.2.6) shown in the following table, dilute each to the mark with the hydrochloric acid (3.2.2) and mix well. 1) At present at the stage of draft. (Partial revision of ISO/R 385:1964.) 2) At present at the stage of draft.BS3900-B7:1986 2 BSI 10-1999 3.4.1.2 Spec
33、trometric measurements Install the antimony spectral source (3.3.2) in the spectrometer (3.3.1) and optimize the conditions for the determination of antimony. Adjust the instrument in accordance with the manufacturers instructions and adjust the monochromator to the region of 217,6nm in order to obt
34、ain the maximum absorbance. Adjust the flow of the acetylene (3.2.3) and of the air(3.2.4) according to the characteristics of the aspirator-burner, and ignite the flame. Set the scale expansion, if fitted, so that the standard matching solution No.4 (see table) gives almost a full-scale deflection.
35、 Aspirate into the flame each of the standard matching solutions (see3.4.1.1) in ascending order of concentration, and repeat with the standard matching solution No.3 to verify that the instrument has achieved stability. Aspirate water through the burner between each measurement, taking care to keep
36、 the rate of aspiration uniform. 3.4.1.3 Calibration graph Plot a graph having the masses, in micrograms, of Sb contained in1ml of the standard matching solutions as abscissae and the corresponding values of the absorbances, reduced by the reading for the blank matching solution, as ordinates. 3.4.2
37、 Test solutions 3.4.2.1 Pigment portion of the liquid paint Mix thoroughly9 parts by volume of each of the solutions obtained by the procedure described in sub-clause8.2.3 of ISO6713 with 1 part by volume of the hydrochloric acid (3.2.1). 3.4.2.2 Liquid portion of the paint Mix thoroughly9 parts by
38、volume of each of the solutions obtained by the procedure described in sub-clause9.3 of ISO6713 with 1 part by volume of the hydrochloric acid (3.2.1). 3.4.2.3 Other test solutions Use the test solutions obtained by other specified or agreed procedures. Take care that the acidity of the solutions is
39、 about1mol/l. 3.4.3 Determination Measure first the absorbance of the hydrochloric acid (3.2.2) in the spectrometer (3.3.1) after having adjusted it as described in3.4.1.2. Then measure the absorbance of each test solution (3.4.2) three times and, afterwards, that of the hydrochloric acid again. Fin
40、ally, re-determine the absorbance of standard matching solution No.3 (see3.4.1.1) in order to verify that the response of the apparatus has not changed. If the absorbance of a test solution is higher than that of the standard matching solution with the highest antimony concentration, dilute the test
41、 solution appropriately (dilution factorF) with a known volume of the hydrochloric acid (3.2.2). 3.5 Interferences Spectral interference occurs in the presence of lead, calcium or copper on the resonance line at217,6nm. In the presence of lead, use the antimony resonance line at206,8nm, or231,1nm. I
42、n the presence of calcium, measure the absorbance at217,0nm and subtract the result from the absorbance at217,6nm. In the presence of copper, use the antimony resonance line at231,1nm. Use a deuterium background corrector to correct forbackground absorption. Alternatively, the solutions can be re-as
43、pirated using a neighbouring non-absorbing line for the background correction (see the note). NOTESome hollow-cathode lamps for antimony have a non-absorbing line at216,9nm. 3.6 Expression of results 3.6.1 Calculations 3.6.1.1 Pigment portion of the liquid paint Calculate the mass of “soluble” antim
44、ony in the hydrochloric acid extract obtained by the method described in sub-clause8.2.3 of ISO6713, using the equation where a 0is the antimony concentration, in micrograms per millilitre, of the blank test solution prepared by the method described in sub-clause8.4 of ISO6713; Standard matching sol
45、utionNo. Volume of the standard antimony solution(3.2.6) Corresponding concentration of Sb in the standard matchingsolution ml 4g/ml 0 a 1 2 3 4 0 5 10 20 40 0 5 10 20 40 a Blank matching solution.BS3900-B7:1986 BSI 10-1999 3 a 1is the antimony concentration, in micrograms per millilitre, of the tes
46、t solution obtained from the calibration graph; F 1is the dilution factor referred to in3.4.3; m 0is the mass, in grams, of “soluble” antimony in the hydrochloric acid extract; V 1is the volume, in millilitres, of the hydrochloric acid plus ethanol used for the extraction described in sub-clause8.2.
47、3 of ISO6713 (assumed to be 77ml). Calculate the “soluble” antimony content of the pigment portion of the paint, using the equation where is the “soluble” antimony content, of the pigment portion of the paint, expressed as a percentage by mass of the paint; m 1is the mass, in grams, of the test port
48、ion taken to prepare the solution described in sub-clause8.2.3 of ISO6713; P is the pigment content of the liquid paint, expressed as a percentage by mass, obtained by the appropriate method described in clause6 of ISO6713. 3.6.1.2 Liquid portion of the paint Calculate the mass of antimony in the so
49、lution (extract), obtained by the method described in sub-clause9.3 of ISO6713, using the equation where b 0is the antimony concentration, in micrograms per millilitre, of the blank test solution prepared by the method described in sub-clause6.5 of ISO6713; b 1is the antimony concentration, in micrograms millilitre, of the test solution obtained from the calibration graph; F 2is the dilution factor referred to in3.4.3; m 2is the mass, in grams, of antimony in the liquid portion of the paint; V 2is the volume, in millilitres, of the solution obtained
