1、Designation: D4834 03 (Reapproved 2014)Standard Test Method forDetection of Lead in Paint by Direct Aspiration AtomicAbsorption Spectroscopy1This standard is issued under the fixed designation D4834; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase 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 con
3、tain 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 D3335.This test method provides a more definitive and reliablescreening test than Test Method D3618.1.2 There
4、 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 include
5、d 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 to u
6、se.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD2832 Guide for Determining Volatile and Nonvolatile Con-tent of Paint and Related CoatingsD3335 Test Method for Low Concentrations of Lead,Cadmium, and Cobalt in Paint by Atomic AbsorptionSpectroscopyD3618 Test Metho
7、d for Detection of Lead in Paint and DriedPaint 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. Lead con
8、tent 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 0.06 %b
9、ased 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 anatomiz
10、er 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 device.5.2
11、 Volumetric Flasks, 50 mL.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 theAmerican
12、Chemical Society, where such specifications areavailable.3Other grades may be used, provided it is firstascertained that the reagent is of sufficiently high purity topermit its use without lessening the accuracy of the determi-nation.1This test method is under the jurisdiction of ASTM Committee D01
13、on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved July 1, 2014. Published July 2014. Originally approvedin 1988. Last previous edition approved in 2008 as D4834
14、03 (2008). DOI:10.1520/D4834-03R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Reagent Chemicals, Americ
15、an Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary,
16、U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16.2 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water conformingto Type II
17、of Specification D1193.6.3 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 Met
18、hod D3335and shown to 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 St
19、andardization7.1 Prepare 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 absorpti
20、on spectro-photometers 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
21、 lamp. Allow the instrument 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
22、corresponding absorbance 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 r
23、eading. Continued response 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 remainshomogeneous during aspiration, the flask containing the specimen may bestirre
24、d continuously with 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 nonv
25、olatile content (see6.4), 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 byco
26、nsulting Guide D2832.8.2 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 wa
27、ter, if it is water 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
28、 7.4) after mixing and measure the absorbance(see Note 1). Aspirate MIBK or water, as appropriate betweenspecimen aspirations. Determine the micrograms of lead pres-ent from the calibration curve.NOTE 3For maximum accuracy, calibration and standardization (SeeSection 7) should be completed just prio
29、r to aspirating the 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 3100!/NV 3 S! (2)where:L = lead in nonvolatile portion of the paint specimen, ppm(g/g),C = lead in the aspirated specimen solution (
30、8.3), g,100 = factor derived from multiplying the numerator by 100(to convert NV used to a whole number) and 106(toobtain ppm) and multiplying the denominator by 106(to convert grams of specimen to micrograms),NV = nonvolatile portion of paint specimen, %, andS = weight of specimen, g.10. Report10.1
31、 Report the lead concentration 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 a
32、nd three samples of 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 criteri
33、ashould 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 should be considered suspect if they differ by more than9.76 % relative.4Supporting data ha
34、ve been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D01-1060. ContactASTM CustomerService at serviceastm.org.D4834 03 (2014)211.1.2 ReproducibilityTwo results, each the mean of du-plicate determinations, obtained by operators in different labo-ratorie
35、s should be considered suspect if they differ by morethan 19.96 % relative.11.2 BiasBias cannot be determined because there are noaccepted standards for lead in paint.12. Keywords12.1 lead contentpaint; lead screening test;spectroscopyatomic adsorptionASTM International takes no position respecting
36、the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of 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
37、 is subject to revision at any time by the responsible technical committee and must be reviewed every five 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
38、Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, 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
39、 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). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 03 (2014)3
