1、BRITISH STANDARD BS 3900-B15: 1987 Methods of test for paints Part B15: Rapid method for estimation of lead in liquid paints It is recommended that this Part be read in conjunction with the general information in the Introduction to BS 3900, issued separately UDC 667.612:667.629.32 168.15BS 3900-B15
2、:1987 This British Standard, having been prepared under the directionof the Pigments, Paintsand Varnishes StandardsCommittee, was published under the authority ofthe Board of BSI and comesintoeffect on 27 February 1987 BSI 07-1999 The Committees responsible forthis British Standard are shown in BS 3
3、900: Introduction The following BSI references relate to the work on this standard: Committee reference PVC/10 Draft for comment 85/55930 DC ISBN 0 580 15610 9 Foreword This Part of BS 3900 has been prepared under the direction of the Pigments, Paints and Varnishes Standards Committee. The method of
4、 test described in this Part is a rapid procedure for the estimation of the amount of lead, within the range of0.01%(m/m) to0.1%(m/m), contained in liquid paint. The result obtained enables a decision to be taken as to whether the estimated lead content justifies an accurate determination of the con
5、tent by one of the methods described in PartB4 of this British Standard. Part B4 of BS3900 describes two methods for the determination, in the liquid product, of the total lead content of paints or similar materials using flame atomic absorption spectroscopy. The referee method for the determination
6、 of lead in the range of about 0.01%(m/m) to2%(m/m) uses a dry ashing procedure to obtain the test solution. An alternative method uses a wet oxidation procedure. It has been assumed in the drafting of this standard that it will be used and applied by those who are appropriately qualified and experi
7、enced. 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 does not of itself confer immunity from legal obligations. Summary of pages This document com
8、prises a front cover, an inside front cover, pages i and ii, pages 1 to 4, an inside back cover and a back cover. 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. Amendments issued s
9、ince publication Amd. No. Date of issue CommentsBS3900-B15:1987 BSI 07-1999 i Contents Page Foreword Inside front cover 1 Scope 1 2 Definitions 1 3 Principle 1 4 Apparatus and materials 1 5 Instrument calibration 1 6 Sampling 1 7 Procedure 1 8 Assessment of results 2 9 Test report 2 Figure 1 Positio
10、n of test strip in the flame 2 Figure 2 Typical recorder traces 3 Figure 3 Sample preparation 4 Table 1 Paint categorization 2 Publications referred to Inside back coverii blankBS3900-B15:1987 BSI 07-1999 1 1 Scope This Part of BS 3900 describes a method for the rapid examination of liquid paint to
11、ascertain the level of lead present in the range 0.01 % (m/m) to0.1% (m/m). The method is not applicable to those paints or similar products (e.g. fillers and putties) that do not allow a drop of the required diameter to be spotted onto a hardened filter paper. It is applicable principally to the ge
12、neral range of decorative and industrial paints. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this Part of BS 3900, the definitions given in BS 2015 apply. 3 Principle A small drop of the paint sample is spotte
13、d onto a hardened filter paper and the lead present estimated by flame atomic absorption spectroscopy. 4 Apparatus and materials 4.1 Flame atomic absorption (A.A.) spectrophotometer, suitable for measurements at a wavelength of 283.3 nm and fitted with a burner fed with acetylene and air. 4.2 Lead s
14、pectral source comprising either a lead hollow-cathode lamp or lead discharge lamp. 4.3 Potentiometer chart recorder 4.4 Acetylene, commercial grade, in a steel cylinder. 4.5 Compressed air 4.6 Hardened filter paper NOTEWhatman No. 541 has been found to be satisfactory. 4.7 Glass rod, of sufficientl
15、y small diameter such that, when a drop of the paint is allowed to fall from it onto the hardened filter paper (4.6), it produces a spot of 4.5 0.5 mm diameter. 4.8 Pair of tongs 4.9 Reference paints, as follows: a) paint A containing a lead content, as Pb, of approximately 100 mg/kg; b) paint B con
16、taining a lead content, as Pb, of approximately 500 mg/kg; c) paint C containing a lead content, as Pb, of approximately 1000 mg/kg. The actual lead content of each of these paints shall be determined using the referee method described in BS 3900-B4. 5 Instrument calibration 5.1 Install the lead spe
17、ctral source (4.2) in the spectrophotometer (4.1) and optimize the conditions for the determination of lead. Adjust the instrument in accordance with the manufacturers instructions, and adjust the monochromator to the region of283.3 nm wavelength in order to obtain the maximum response. Lower the bu
18、rner of the spectrophotometer to its minimum height. Adjust the flow of the acetylene (4.4) and of the compressed air (4.5) according to the characteristics of the aspirator and burner, and ignite the flame. 5.2 As described in 7.2, prepare a test strip of hardened filter paper and apply a drop of p
19、aintC4.9 c). Using the pair of tongs (4.8), insert the paint spot on the test strip into the flame, as shown in Figure 1, and adjust the instruments conditions, so that the peak shown on the potentiometer chart recorder (4.3) is as close as possible to the maximum width of the chart recorder paper.
20、Repeat this procedure until three successive test strips give the same response to within 5 %. 5.3 Without further adjustment of the instruments conditions, carry out the procedure described in 7.2 to 7.4 for paint A 4.9 a), paint B 4.9 b) and paintC 4.9 c) to establish their peak heights. 5.4 Calcu
21、late for each peak, by proportion to the lead content, as Pb, of the reference paint, the response corresponding to 100 mg/kg, 500 mg/kg or100 mg/kg as appropriate, and mark these adjusted responses A, B or C on the chart (see Figure 2). 6 Sampling Take a representative sample of the product to be t
22、ested as described in BS 3900-A1. Examine and prepare the sample as described in BS3900-A2. 7 Procedure 7.1 Carry out this determination in triplicate. 7.2 Cut a strip, approximately 12 mm 38 mm, from the hardened filter paper. Dip the glass rod (4.7) into the paint sample (clause6), previously stir
23、red until homogeneous. Withdraw the glass rod and allow a drop of the paint to fall from the rod onto the hardened filter paper, centred at the position shown in Figure 3, to produce a spot of 4.5 0.5 mm diameter. Fold the strip centrally along its length (see Figure 3). NOTE Thixotropic paints, eve
24、n after vigorous stirring, may present difficulties in forming a spot of the specified size.BS 3900-B15:1987 2 BSI 07-1999 7.3 Using the pair of tongs, insert the paint spot on the strip into the flame of the spectrophotometer as described in 5.2, maintaining the established operating conditions. No
25、te the response on the potentiometer chart recorder. 7.4 Repeat the procedure described in 7.2 and 7.3 until three responses agree to within 5%. If the variation in response exceeds 5 %, check the instrument calibration (5.2). 8 Assessment of results 8.1 Compare each response obtained for the produc
26、t under test with the adjusted responses A, B and C obtained as described in clause 5 and as illustrated in Figure 2. Assess the product under test by reference to Table 1. Table 1 Paint categorization 8.2 Record the category appropriate to the lead content indicated by the response on the potentiom
27、eter recorder chart. Alternatively, record the lead content, as Pb, as “below/above x mg/kg”, where x is the maximum permitted lead content in the relevant product specification or legislation. NOTEBy consideration of the category assigned to the product under test, a decision may be made as to whet
28、her, in view of the lead content permitted in the product specification or legislation, the lead content should be verified by the method described in BS3900-B4. Unless previous experience indicates otherwise, if the lead content, as estimated by the method given in this Part, is greater than 50 % o
29、f the specified limit, the accurate quantitative determination is recommended. 9 Test report The test report shall contain the following information: a) the type and identification of the product under test; b) reference to this standard, i.e. BS 3900-B15; c) the stated requirements given in the rel
30、evant product specification or legislation; d) any supplementary information provided with regard to c) of this clause; e) the results of the test in accordance with clause8; f) any deviation, agreed or otherwise, from the test procedure described; g) the date of the test. Lead content, as Pb Catego
31、ry mg/kg u 100 100 but u 500 500 but u 1 000 1 2 3 Figure 1 Position of test strip in the flameBS3900-B15:1987 BSI 07-1999 3 Figure 2 Typical recorder tracesBS 3900-B15:1987 4 BSI 07-1999 Figure 3 Sample preparationBS3900-B15:1987 BSI 07-1999 Publications referred to BS 2015, Glossary of paint terms
32、. BS 3900, Methods of test for paints. BS 3900-A1, Sampling. BS 3900-A2, Examination and preparation of samples for testing. BS 3900-B4, Determination of total lead in paints and similar materials. BS 3900-B15: 1987 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the i
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