1、Designation: E 1644 04Standard Practice forHot Plate Digestion of Dust Wipe Samples for theDetermination of Lead1This standard is issued under the fixed designation E 1644; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the acid digestion of surface dustsamples (collected using wipe sampling practices) and associ
3、-ated quality control (QC) samples for the determination oflead.1.2 The values stated in SI units are to be regarded as thestandard.1.3 This practice contains notes which are explanatory andnot part of mandatory requirements of the standard.1.4 This standard does not purport to address all of thesaf
4、ety 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 use.2. Referenced Documents2.1 ASTM Standards:2D 1129 Terminology Relating to
5、WaterD 1193 Specification for Reagent WaterE 1605 Terminology Relating to Lead in BuildingsE 1613 Test Method for Determination of Lead by Induc-tively Coupled Plasma Atomic Emission Spectrometry(ICP-AES), Flame Atomic Absorption Spectrometry(FAAS), or Graphite Furnace Atomic Absorption Spec-trometr
6、y (GFAAS) TechniquesE 1724 Guide for Testing and Certification of Metal andMetal-Related Reference MaterialsE 1728 Practice for Collection of Settled Dust SamplesUsing Wipe Sampling Methods for Subsequent LeadDeterminationE 1792 Specification for Wipe Sampling Materials for Leadin Surface DustE 2051
7、 Practice for the Determination of Lead in Paint,Settled Dust, Soil and Air Particulate by Field-PortableElectroanalysisE 2239 Practice for Record Keeping and Record Preserva-tion for Lead Hazard Activities2.2 Other Documents:EPA SW 846, Method 3050, “Acid Digestion of Sediments,Sludges, and Soils.”
8、 This method is found in Test Methodsfor Evaluating Solid Waste, Physical/Chemical Methods,U.S. EPA SW 846, 3rd Edition, Revision 1, 19873NIOSH Manual of Analytical Methods, NIOSH 7082 and7105, Eller, P.M., Ed., 3rd ed., 198433. Terminology3.1 DefinitionsFor definitions of terms not appearinghere, r
9、efer to Terminologies D 1129 and E 1605.3.2 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, spiked, and spiked duplicate quality as
10、surance 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 digestion vessel. (The same reagen
11、tsand 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 sampling medium sourcesthat are experie
12、nced 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-spikedsample is equivalent to a method bla
13、nk. 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 August 1, 2004. Published August 2004. Originallyapproved in 1
14、994. Last previous edition approved in 1998 as E 1644 98.2For 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.3Ava
15、ilable from National Technical Information Service (NTIS), U.S. Depart-ment of Commerce, 5285 Port Royal Rd., Springfield, VA 22161.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.this sample are used to correct for background levels
16、 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 batch exceptthat it has no sample placed into the digestion vessel. (Thesame reagents and processing conditions that are applied tofi
17、eld 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 contaminationresulting from only laboratory sources that are experienced bysamples processed within the batch.3.2.6 spiked sample and s
18、piked 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 DiscussionAnalysis results for these samples areused to provide information on accuracy and precision of theoverall analysis process.4. Summa
19、ry 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 lead measurement.NOTE 1The procedure in this practice is based on U.S. EPA SW846Method 3050, NIOSH 7082, and NIOSH 7105.5. Significanc
20、e 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 and related structures.5.2 This practice is also intended for the digestion of lead indust wipe samples collected during and after bui
21、lding renova-tions.5.3 This practice is applicable to the digestion of dust wipesamples that have or have not been collected in accordancewith Practice E 1728 using wipes that may or may not conformto Specification E 1792.5.4 This practice is applicable to the digestion of dust wipesamples that were
22、 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 ofsome samples from plastic bags, hard-walled rigid containers such as50-mL plastic centrifuge tubes are recommended for sample coll
23、ection.5.5 Digestates prepared according to this practice are in-tended to be analyzed for lead concentration using spectromet-ric techniques such as Inductively Coupled Plasma AtomicEmission Spectrometry (ICP-AES) and Flame Atomic Absorp-tion Spectrometry (FAAS) (see Test Method E 1613), or usingel
24、ectrochemical techniques such as anodic stripping voltam-metry (see Practice E 2051).5.6 This practice is not capable of determining lead boundwithin matrices, such as silica, that are not soluble in nitricacid.5.7 This practice is capable of determining lead boundwithin paint.6. Apparatus and Mater
25、ials6.1 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,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
26、.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 ThermometersRed alcohol or thermocouple, that cov-ers a range of 0 to 150C.6.5 Electric Hot PlateSuitable for operation at tempera-ture
27、s 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 plateplaced on the burner head can help reduce the presence of hot spotscommon to electric hot plates.6.6 Vinyl GlovesPowderless.6
28、.7 Micropipettors with Disposable Plastic TipsSizesneeded to make reagent additions, and spike standards. Ingeneral, the following sizes should be readily available: 1 to 5mL adjustable, 100 L, 500 L, 250 L, and 1000 L.7. Reagents7.1 Purity of ReagentsReagent grade chemicals shall beused in this pra
29、ctice. Unless otherwise indicated, it is intendedthat all reagents conform to the specifications of the Committeeon Analytical Reagents of the American Chemical Society,where such specifications are available.4Other grades may beused, provided it is first ascertained that the reagent is ofsufficient
30、ly high purity to permit its use without lesseningaccuracy of the determination.7.2 Nitric AcidConcentrated, suitable for atomic spec-trometry analysis such as spectroscopic grade.7.3 Hydrogen Peroxide30 % (w/w), suitable for atomicspectrometry analysis such as spectroscopic grade.7.4 Purity of Wate
31、rUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Type 1 of Specification D 1193.57.5 Calibration Stock Solution100 g/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
32、.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 new pair of plastic gloves or plastic forceps, orboth, and place it into the Beaker.4Reagent Chemicals, American Chemical Societ
33、y 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, U.S. Pharmaceutica
34、l Convention, Inc. (USPC), Rockville,MD.5ASTM Type I Water: Minimum resistance of 16.67 megohm-cm, or equivalent.E16440428.1.2.2 If the sample container 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
35、 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 be left behind after wipe removal, attemptto transfer the residual material into the beaker by shaking orusing mechanical removal with a clean laborat
36、ory spatula orsimilar tool. Document observations of potential loss of sampledue to residue in the container for later reporting with theresults of the 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
37、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 thermometer 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
38、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 to effect efficient extraction.(CautionSome wipes break down into a gelatinous residuethat readily bumps or spatters, or both. Heating should beslowe
39、d 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 reflux 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
40、6). Allow the sample to cool to near room temperatureafter evaporation to approximately 10 mL.NOTE 5Exercise care when removing the watch glass. Avoid leadcontamination problems by placing it upside down on new clean labora-tory wipes.NOTE 6Boiling of the sample should be avoided because of potentia
41、lsample losses due to splattering and cross-contamination problems. Thesame problems can be experienced if samples are allowed to evaporate todryness.8.1.7 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
42、 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 vigorouseffervescence during heating. Heat until effervescence subsidesand cool the beaker to near room temperature.8.1.8 Remove the watch glass and continue
43、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 cool to near room temperature,rinse the beaker walls and bottom of the watch glass withwater, and quantitatively transfer through a funnel equippedwit
44、h 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 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 dige
45、state solution contains approxi-mately 10 % (v/v) nitric acid. Calibration standards used forinstrumental measurement should be made with this level ofnitric acid.NOTE 7The wipe material may or may not be completely solubilized.Many types of wipes contain materials that do not dissolve in nitric aci
46、d.9. Quality Assurance9.1 Quality Control Samples:9.1.1 Reagent Blank SamplesProcess reagent blanks ac-cording to the frequency listed in Table 1. Submit reagentblanks to the entire dust-wipe sample preparation and digestionprocess to determine through subsequent lead analysis if thesamples are bein
47、g contaminated from laboratory activities.9.1.2 Non-Spiked, Spiked, and Spiked Duplicate SamplesProcess non-spiked, spiked, and spiked duplicate samples (thatis, blank wipes) at the frequency listed in Table 1, expressedthrough subsequent analysis as percent lead recovery relativeto the true spiked
48、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 personnel isinsufficient, use wipes that conform to Specification E 1792.9.1.2.1 To the extent possible, the brand or type of blankwipe used should be the
49、 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 9). In the absenceof other information, add 2 mL of the 100 mg/mL calibrationstock solution (that is, 200 mg of lead) to the beaker with theblank wipe.NOTE
