1、Designation: E1644 04 (Reapproval 2012)1Standard Practice forHot Plate Digestion of Dust Wipe Samples for theDetermination of Lead1This standard is issued under the fixed designation E1644; the number immediately following the designation indicates the year oforiginal adoption or, in the case of rev
2、ision, 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.1NOTEEditorial corrections made to Section 2 in April 2012.1. Scope1.1 This practice covers the acid digestion
3、of surface dustsamples (collected using wipe sampling practices) and associ-ated quality control (QC) samples for the determination oflead.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This practice contains notes whic
4、h are explanatory andnot part of mandatory requirements of the standard.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 t
5、he applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent WaterE1605 Terminology Relating to Lead in BuildingsE1613 Test Method for Determination of Lead by Induc-tively Coupled Plasma Atomic
6、 Emission Spectrometry(ICP-AES), Flame Atomic Absorption Spectrometry(FAAS), or Graphite Furnace Atomic Absorption Spec-trometry (GFAAS) TechniquesE1728 Practice for Collection of Settled Dust SamplesUsing Wipe Sampling Methods for Subsequent LeadDeterminationE1792 Specification for Wipe Sampling Ma
7、terials for Leadin Surface DustE2051 Practice for the Determination of Lead in Paint,Settled Dust, Soil and Air Particulate by Field-PortableElectroanalysis3E2239 Practice for Record Keeping and Record Preserva-tion for Lead Hazard Activities2.2 Other Documents:EPA SW 846, Method 3050, “Acid Digesti
8、on of Sediments,Sludges, and Soils.” This method is found in Test Methodsfor Evaluating Solid Waste, Physical/Chemical Methods,U.S. EPA SW 846, 3rd Edition, Revision 1, 19874NIOSH Manual of Analytical Methods, NIOSH 7082 and7105, Eller, P.M., Ed., 3rd ed., 198443. Terminology3.1 DefinitionsFor defin
9、itions of terms not appearinghere, refer to Terminologies D1129 and E1605.3.2 Definitions of Terms Specific to This Standard:3.2.1 blank wipean unused, unspiked dust wipe that isonly removed from its packaging immediately before use.3.2.1.1 DiscussionBlank wipes are used to prepare non-spiked, spike
10、d, and spiked duplicate quality assurance samples.3.2.2 dust wipe samplesurface dust collected on a wipe.3.2.3 method blanka digestate that reflects the maximumtreatment given any one sample within a sample batch exceptthat only the sampling medium (such as a blank wipe) isinitially placed into the
11、digestion vessel. (The same reagentsand processing conditions that are applied to field sampleswithin a batch are also applied to the method blanks.)3.2.3.1 DiscussionAnalysis results from method blanksprovide information on the level of potential contaminationresulting from the laboratory and sampl
12、ing medium sourcesthat are experienced by samples processed within the batch.3.2.4 non-spiked samplea portion of a homogenizedsample that was targeted for the addition of analyte but is notfortified with the target analytes before sample preparation.3.2.4.1 DiscussionFor wipe samples, a non-spikedsa
13、mple is equivalent to a method blank. Analysis results for1This practice is under the jurisdiction of ASTM Committee E06 on Perfor-mance of Buildings and is the direct responsibility of Subcommittee E06.23 on LeadHazards Associated with Buildings.Current edition approved April 1, 2012. Published May
14、 2012. Originallyapproved in 1994. Last previous edition approved in 2004 as E1644 04. DOI:10.1520/E1644-04R12.2For 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 s
15、tandards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.4Available from National Technical Information Service (NTIS), 5301 ShawneeRd., Alexandria, VA 22312, http:/www.ntis.gov.1Copyright ASTM International, 100
16、 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.this sample are used to correct for background levels in theblank wipes used for spiked and spiked duplicate samples.3.2.5 reagent blanka digestate that reflects the maximumtreatment given any one sample within a sample
17、 batch exceptthat it has no sample placed into the digestion vessel. (Thesame reagents and processing conditions that are applied tofield samples within a batch are also applied to the reagentblank.)3.2.5.1 DiscussionAnalysis results from reagent blanksprovide information on the level of potential c
18、ontaminationresulting from only laboratory sources that are experienced bysamples processed within the batch.3.2.6 spiked sample and spiked duplicate samplea blankwipe that is spiked with a known amount of analyte (that is,lead) before hot plate digestion and subsequent lead analysis.3.2.6.1 Discuss
19、ionAnalysis results for these samples areused to provide information on accuracy and precision of theoverall analysis process.4. Summary of Practice4.1 A dust wipe sample is digested using hot plate typeheating with nitric acid and hydrogen peroxide. The digestateis diluted to final volume prior to
20、lead measurement.NOTE 1The procedure in this practice is based on U.S. EPA SW846Method 3050, NIOSH 7082, and NIOSH 7105.5. Significance and Use5.1 This practice is intended for the digestion of lead in dustwipe samples collected during various lead hazard activitiesperformed in and around buildings
21、and related structures.5.2 This practice is also intended for the digestion of lead indust wipe samples collected during and after building renova-tions.5.3 This practice is applicable to the digestion of dust wipesamples that have or have not been collected in accordancewith Practice E1728 using wi
22、pes that may or may not conformto Specification E1792.5.4 This practice is applicable to the digestion of dust wipesamples that were placed in either hard-walled, rigid containerssuch as 50-mL centrifuge tubes or flexible plastic bags.NOTE 2Due to the difficulty in performing quantitative transfers
23、ofsome samples from plastic bags, hard-walled rigid containers such as50-mL plastic centrifuge tubes are recommended for sample collection.5.5 Digestates prepared according to this practice are in-tended to be analyzed for lead concentration using spectromet-ric techniques such as Inductively Couple
24、d Plasma AtomicEmission Spectrometry (ICP-AES) and Flame Atomic Absorp-tion Spectrometry (FAAS) (see Test Method E1613), or usingelectrochemical techniques such as anodic stripping voltam-metry (see Practice E2051).5.6 This practice is not capable of determining lead boundwithin matrices, such as si
25、lica, that are not soluble in nitricacid.5.7 This practice is capable of determining lead boundwithin paint.6. Apparatus and Materials6.1 Borosilicate Glassware:6.1.1 Class A Volumetric Flasks with Stoppers, 100 mL andother sizes needed to make serial dilutions,6.1.2 Griffn Beakers, 150 mL or 250 mL
26、,6.1.3 Watch Glasses, sized to cover Griffin beakers,6.1.4 Class A Pipets, as needed to make serial dilutions, and6.1.5 Glass Rods.6.2 FunnelsPlastic or porcelain or borosilicate funnelssized to fit into a 100-mL volumetric flask.6.3 Filter PaperFast filtering, suitable for metals analysis.6.4 Therm
27、ometersRed alcohol or thermocouple, that cov-ers a range of 0 to 150C.6.5 Electric Hot PlateSuitable for operation at tempera-tures up to at least 100C (see Note 3).NOTE 3Provided that the hot plate is capable of handling the extraheating required, use of a 12 to 25-mm (0.5 to 1-in.) thick aluminum
28、plateplaced on the burner head can help reduce the presence of hot spotscommon to electric hot plates.6.6 Vinyl GlovesPowderless.6.7 Micropipettors with Disposable Plastic TipsSizesneeded to make reagent additions, and spike standards. Ingeneral, the following sizes should be readily available: 1 to
29、 5mL adjustable, 100 L, 500 L, 250 L, and 1000 L.7. Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in this practice. Unless otherwise indicated, it is intendedthat all reagents conform to the specifications of the Committeeon Analytical Reagents of the American Chemical Society,w
30、here such specifications are available.5Other grades may beused, provided it is first ascertained that the reagent is ofsufficiently high purity to permit its use without lesseningaccuracy of the determination.7.2 Nitric AcidConcentrated, suitable for atomic spec-trometry analysis such as spectrosco
31、pic grade.7.3 Hydrogen Peroxide30 % (w/w), suitable for atomicspectrometry analysis such as spectroscopic grade.7.4 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Type 1 of Specification D1193.67.5 Calibration Stock Solution100 g/
32、mL of Pb in dilutenitric acid.8. Sample Preparation Procedure8.1 Sample Extraction:8.1.1 Treat each sample in a batch equally.8.1.2 Quantitatively transfer the contents of the dust-wipesample container to a labeled beaker as follows:8.1.2.1 Carefully open the container, remove the foldedwipe using a
33、 new pair of plastic gloves or plastic forceps, orboth, and place it into the Beaker.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for
34、 LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.6ASTM Type I Water: Minimum resistance of 16.67 megohm-cm, or equivalent.E1644 04 (Reapproval 2012)128.1.2.2 If the sample containe
35、r is a hard-walled, rigidcontainers such as a plastic centrifuge tube, rinse out the insideof the container into the beaker with two small volumes (2 to3 mL) of water using a squirt bottle filled with ASTM Type Iwater.8.1.2.3 If the sample container is a flexible plastic bag andmaterial appears to b
36、e left behind after wipe removal, attemptto transfer the residual material into the beaker by shaking orusing mechanical removal with a clean laboratory spatula orsimilar tool. Document observations of potential loss of sampledue to residue in the container for later reporting with theresults of the
37、 lead analysis.8.1.3 Add 25 mL of 1:1 nitric acid:water to the beaker,gently swirl to mix, and cover with a watch glass. Gently heatthe sample to 85 to 100C using the hot plate and reflux for 10to 15 min without boiling. Estimate and monitor the tempera-ture of the sample solution by having a thermo
38、meter inside abeaker or flask containing a small volume (about 25 mL) ofwater on the hot plate (see Note 4).NOTE 4A hot plate surface temperature of 120 to 140C will yield asample digestate temperature of 85 to 100C.8.1.4 Using a glass rod, push the wipe down into thedigestion solution periodically
39、to effect efficient extraction.(CautionSome wipes break down into a gelatinous residuethat readily bumps or spatters, or both. Heating should beslowed with these materials.)8.1.5 Allow the sample to cool to near room temperature,add 10 mL of concentrated nitric acid, replace the watch glass,and refl
40、ux for 30 min without boiling.8.1.6 Remove the watch glass and allow the solution toevaporate to approximately 10 mL without boiling (see Notes5 and 6). Allow the sample to cool to near room temperatureafter evaporation to approximately 10 mL.NOTE 5Exercise care when removing the watch glass. Avoid
41、leadcontamination problems by placing it upside down on new clean labora-tory wipes.NOTE 6Boiling of the sample should be avoided because of potentialsample losses due to splattering and cross-contamination problems. Thesame problems can be experienced if samples are allowed to evaporate todryness.8
42、.1.7 After the sample has cooled to near room temperature,add 5 mLof water and 5 mLof 30 % hydrogen peroxide. Coverthe beaker with the watchglass and return the covered beaker tothe hot plate for warming and to start the peroxide reaction.Take care to ensure that losses do not occur due to vigorouse
43、ffervescence during heating. Heat until effervescence subsidesand cool the beaker to near room temperature.8.1.8 Remove the watch glass and continue heating theacid-peroxide digestate carefully until the volume has beenreduced to approximately 10 mL (see Notes 5 and 6).8.1.9 Allow the digestate to c
44、ool to near room temperature,rinse the beaker walls and bottom of the watch glass withwater, and quantitatively transfer through a funnel equippedwith a fast filter into a 100-mL volumetric flask (see Note 6).If a large amount of undissolved material remains in thebeaker, rinse this residue as many
45、times as necessary to transfersolubilized lead into the 100 mL volumetric flask. Dilute tovolume with water and swirl to mix.8.1.9.1 The diluted digestate solution contains approxi-mately 10 % (v/v) nitric acid. Calibration standards used forinstrumental measurement should be made with this level of
46、nitric acid.NOTE 7The wipe material may or may not be completely solubilized.Many types of wipes contain materials that do not dissolve in nitric acid.9. Quality Assurance9.1 Quality Control Samples:9.1.1 Reagent Blank SamplesProcess reagent blanks ac-cording to the frequency listed in Table 1. Subm
47、it reagentblanks to the entire dust-wipe sample preparation and digestionprocess to determine through subsequent lead analysis if thesamples are being contaminated from laboratory activities.9.1.2 Non-Spiked, Spiked, and Spiked Duplicate SamplesProcess non-spiked, spiked, and spiked duplicate sample
48、s (thatis, blank wipes) at the frequency listed in Table 1, expressedthrough subsequent analysis as percent lead recovery relativeto the true spiked value. Use blank wipes provided by fieldpersonnel who submitted the dust wipe samples (see Note 8).If the number of blank wipes provided by field perso
49、nnel isinsufficient, use wipes that conform to Specification E1792.9.1.2.1 To the extent possible, the brand or type of blankwipe used should be the same as that used for the collection ofthe dust wipe samples.9.1.2.2 Since wipe samples cannot be split uniformly, blankwipes are used for non-spiked, spiked, and spiked duplicatesamples.9.1.2.3 Preparation of Spiked and Spiked DuplicateSamplesFor a blank wipe targeted for spiking, add anappropriate volume of a lead standard stock solution to abeaker that contains a blank wipe (see Note
