1、Designation: D 4834 03 (Reapproved 2008)Standard Test Method forDetection of Lead in Paint by Direct Aspiration AtomicAbsorption Spectroscopy1This standard is issued under the fixed designation D 4834; the number immediately following the designation indicates the year oforiginal adoption or, in the
2、 case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is intended as a screening test todetermine if the solids in a paint c
3、ontain more than 0.06 %lead. The test described can differentiate between 0.05 and0.06 %. Paints giving a result greater than 0.05 % should beanalyzed quantitatively for lead using Test Method D 3335.This test method provides a more definitive and reliablescreening test than Test Method D 3618.1.2 T
4、here is no reason to believe that higher levels of leadcould not be determined by this test method provided thatappropriate dilutions and adjustments in specimen size andreagent quantities are made.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are inc
5、luded in thisstandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior
6、to use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 2832 Guide for Determining Volatile and NonvolatileContent of Paint and Related CoatingsD 3335 Test Method for Low Concentrations of Lead,Cadmium, and Cobalt in Paint by Atomic AbsorptionSpectroscopyD 3618 Test
7、 Method for Detection of Lead in Paint andDried Paint Films3. Summary of Test Method3.1 A weighed quantity of the paint sample is diluted(solvent-reducible paints in methyl isobutyl ketone and water-reducible paints in water) and then aspirated into the burner ofan atomic absorption spectrometer. Le
8、ad content of the paint isdetermined from a calibration plot of absorbance versusconcentration, prepared from standard coatings containingknown amounts of lead.4. Significance and Use4.1 Current U.S. regulations restrict the amount of lead thatmay be present in consumer paint products to less than 0
9、.06 %based on the total solids. This test method provides a rapidmeans for screening paints to determine compliance with thoseregulations. The test method may be adjusted to meet regula-tions with a different limit on lead content.5. Apparatus5.1 Atomic Absorption Spectrophotometer, consisting of an
10、atomizer and either a single- or a three-slot burner, gas pressureregulating and metering devices for air and acetylene, leadsource lamp with a regulated constant-current supply, a mono-chromator and associated optics, a photosensitive detectorconnected to an electronic amplifier, and a readout devi
11、ce.5.2 Volumetric Flasks,50mL.6. Reagent and Materials6.1 Purity of ReagentsReagent grade chemicals shall beused in all tests unless otherwise specified. Unless otherwiseindicated, it is intended that all reagents shall conform to thespecifications of the Committee on Analytical Reagents of theAmeri
12、can Chemical Society, where such specifications areavailable.3Other grades may be used, provided it is first1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical A
13、nalysis of Paints and Paint Materials.Current edition approved Nov. 1, 2008. Published November 2008. Originallyapproved in 1988. Last previous edition approved in 2003 as D 4834 03.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.o
14、rg. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemic
15、al Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2
16、959, United States.ascertained that the reagent is of sufficiently high purity topermit its use without lessening the accuracy of the determi-nation.6.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Type II of Specification D 119
17、3.6.3 Methyl Isobutyl Ketone (MIBK), technical grade.6.4 Standard PaintsPrepare at least 3 standard paints byadding accurately weighed quantities of an analytically assayedcompatible lead compound to a solvent-reducible or water-reducible paint that has been analyzed by Test Method D 3335and shown t
18、o contain less than 10 ppm of lead. Determine thenonvolatile content of the base paint and choose quantities ofthe lead compound so that the lead concentrations of thestandard paints will be approximately 300, 600, and 900 g/gbased on the nonvolatile content.7. Calibration and Standardization7.1 Pre
19、pare at least three solvent-reducible or water-reducible standard paint specimens (see 6.4) that bracket theexpected lead concentration in the sample to be tested. Fol-lowing the procedure in 8.2 dilute the standards for aspiration.7.2 Operational instructions for atomic absorption spectro-photomete
20、rs vary with different models. Consult the manufac-turers literature for establishing optimum conditions for thespecific instrument used.7.3 Turn the instrument on and set the wavelength to the283.3-nm lead line. Apply the current recommended by themanufacturer to the lead source lamp. Allow the ins
21、trument towarm up for about 15 min and set the slit width. Adjust the airand acetylene pressure or flow rates and ignite the burner inaccordance with the manufacturers instructions.Abackgroundcorrector should be used.7.4 Aspirate each of the diluted standard paints and recordthe corresponding absorb
22、ance readings. Aspirate MIBK orwater, as appropriate, between standards. (WarningIt isimportant that MIBK or water be aspirated immediately aftereach diluted standard paint to minimize fouling of theaspirator/nebulizer system which could change the aspirationrate and absorbance reading. Continued re
23、sponse for lead whileaspirating MIBK or water may indicate contamination of theburner head with pigment and require cleaning of the burnerhead.)NOTE 1To be certain that the diluted paint specimen remains homo-geneous during aspiration, the flask containing the specimen may bestirred continuously wit
24、h a small magnetic stirring bar.7.5 Construct a calibration curve on linear graph paper byplotting the absorbance readings versus micrograms of leadpresent in each diluted standard paint as follows:A 5 B 3 D 3 E! (1)where:A = lead present, g,B = lead in standard paint based on nonvolatile content (s
25、ee6.4), g/g,D = weight of standard paint, g, andE = nonvolatile portion of standard paint, %.8. Procedure8.1 Mix the paint to be tested until homogeneous, preferablyon a mechanical shaker. Determine the nonvolatile content inaccordance with the appropriate test method selected byconsulting Guide D 2
26、832.8.2 Prepare at least two replicate specimens by weighing bydifference from a weighing bottle or disposable syringe to 0.1mg, 0.5 6 0.02-g quantities of the paint being tested, into 10mL volumetric flasks. Dilute to the mark with MIBK, if thepaint is solvent reducible, or with water, if it is wat
27、er reducible.Mix thoroughly.NOTE 2Adjustment of specimen size and dilution volume may bemade as required for linear calibration and reasonable response for theinstrument used as well as for differing lead content limits.8.3 Aspirate the diluted paint specimens immediately(WarningSee 7.4) after mixin
28、g and measure the absorbance(see Note 1). Aspirate MIBK or water, as appropriate betweenspecimen aspirations. Determine the micrograms of leadpresent from the calibration curve.NOTE 3For maximum accuracy, calibration and standardization (SeeSection 7) should be completed just prior to aspirating the
29、 diluted paintspecimen.9. Calculation9.1 Calculate the mean concentration of lead in the nonvola-tile portion of the paint specimen as follows:L 5 C 3 100!/NV 3 S! (2)where:L = lead in nonvolatile portion of the paint specimen,ppm (g/g),C = lead in the aspirated specimen solution (8.3), g,100 = fact
30、or derived from multiplying the numerator by100 (to convert NV used to a whole number) and106(to obtain ppm) and multiplying the denominatorby 106(to convert grams of specimen to micro-grams),NV = nonvolatile portion of paint specimen, %, andS = weight of specimen, g.10. Report10.1 Report the lead c
31、oncentration expressed on the non-volatile content of the paint sample.11. Precision and Bias411.1 PrecisionThe precision estimates are based on aninterlaboratory study in which five different laboratories ana-lyzed in duplicate on 2 days, three samples of solvent-reduciblepaints and three samples o
32、f water-reducible paints containingfrom 464 to 742 ppm lead. The within-laboratory coefficient ofvariation was found to be 3.34 % relative at 24 df and thebetween-laboratories coefficient of variation was 6.72 % rela-tive at 18 df. Based on these coefficients, the following criteria4Supporting data
33、is available from ASTM International Headquarters. RequestRR: D01-1060.D 4834 03 (2008)2should be used for judging the acceptability of results at the95 % confidence level:11.1.1 RepeatabilityTwo results, each the mean of dupli-cate determinations, obtained by the same operator on differentdays shou
34、ld be considered suspect if they differ by more than9.76 % relative.11.1.2 ReproducibilityTwo results, each the mean of du-plicate determinations, obtained by operators in different labo-ratories should be considered suspect if they differ by morethan 19.96 % relative.11.2 BiasBias cannot be determi
35、ned because there are noaccepted standards for lead in paint.12. Keywords12.1 lead contentpaint; lead screening test;spectroscopyatomic adsorptionASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of
36、 this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five
37、 years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical co
38、mmittee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 4834 03 (2008)3
