1、Designation: D 5756 02Standard Test Method forMicrovacuum Sampling and Indirect Analysis of Dust byTransmission Electron Microscopy for Asbestos MassSurface Loading1This standard is issued under the fixed designation D 5756; the number immediately following the designation indicates the year oforigi
2、nal adoption or, in the case of revision, the year of 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 test method covers a procedure to (a) identifyasbestos in
3、dust and (b) provide an estimate of the surfaceloading of asbestos in the sampled dust, reported as either themass of asbestos per unit area of sampled surface or as themass of asbestos per mass of sampled dust.1.1.1 If an estimate of asbestos structure counts is to bedetermined, the user is referre
4、d to Test Method D 5755.1.2 This test method describes the equipment and proce-dures necessary for sampling, by a microvacuum technique,non-airborne dust for levels of asbestos. The non-airbornesample is collected inside a standard filter membrane cassettefrom the sampling of a surface area for dust
5、 which may containasbestos.1.2.1 This procedure uses a microvacuuming sampling tech-nique. The collection efficiency of this technique is unknown.Variability of collection efficiency for any particular substrateand across different types of substrates is also unknown. Theeffects of sampling efficien
6、cy differences and variability on theinterpretation of dust sampling measurements have not beendetermined.1.3 Asbestos identified by transmission electron microscopy(TEM) is based on morphology, selected area electron diffrac-tion (SAED), and energy dispersive X-ray analysis (EDXA).Some information
7、about structure size is also determined.1.4 This test method is generally applicable for an estimateof the surface loading of asbestos starting from approximately0.24 pg of asbestos per square centimetre (assuming a mini-mum fiber dimension of 0.5 m by 0.025 m, see 17.8), butwill vary with the analy
8、tical parameters noted in 17.8.1.4.1 The procedure outlined in this test method employs anindirect sample preparation technique. It is intended to disag-gregate and disperse asbestos into fibrils and fiber bundles thatcan be more accurately identified, counted, and sized bytransmission electron micr
9、oscopy. However, as with all indi-rect sample preparation techniques, the asbestos observed forquantitation may not represent the physical form of theasbestos as sampled. More specifically, the procedure de-scribed neither creates not destroys asbestos, but it may alterthe physical form of the miner
10、al fibers.1.5 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.6 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 est
11、ablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 3195 Practice for Rotameter CalibrationD 5755 Test Method for Microvacuum Sampling and Indi-rect
12、Analysis of Dust by Transmission Electron Micros-copy for Asbestos Structure Number surface loadingsD 6620 Practice for Determining a Detection Limit forAsbestos Measurements Based on CountsE 832 Specification for Laboratory Filter Papers2.2 ISO Standards:ISO/10312 Ambient Air: Determination of Asbe
13、stos Fibers;Direct Transfer Transmission Electron Microscopy Proce-dure3ISO/CD13794 Ambient Air: Determination of Asbestos Fi-bres; Indirect-Transfer Transmission Electron MicroscopyProcedure33. Terminology3.1 Definitions:3.1.1 asbestiforma special type of fibrous habit in whichthe fibers are separa
14、ble into thinner fibers and ultimately into1This test method is under the jurisdiction of ASTM Committee D22 onSampling and Analysis of Atmospheres and is the direct responsibility of Subcom-mittee D22.07 on Sampling and Analysis of Asbestos.Current edition approved November 10, 2002. Published Janu
15、ary 2003. Origi-nally approved in 1995. Last previous edition approved in 1995 as D5756 - 95.2For 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
16、Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.fibrils. This habit accoun
17、ts for greater flexibility and highertensile strength than other habits of the same mineral. For moreinformation on asbestiform mineralogy, see references (1), (2)and (3).43.1.2 asbestosa collective term that describes a group ofnaturally occurring, inorganic, highly fibrous silicate minerals,which
18、are easily separated into long, thin, flexible fibers whencrushed or processed.3.1.2.1 DiscussionIncluded in the definition are the as-bestiform varieties of: serpentine (chyrsotile); riebeckite (cro-cidolite); grunerite (amosite); anthophyllite (anthophyllite as-bestos); tremolite (tremolite asbest
19、os); and actinolite (actinoliteasbestos). The amphibole mineral compositions are definedaccording to the nomenclature of the International Mineralogi-cal Association (3).AsbestosChemical Abstract ServiceNo.5Chrysotile 12001-29-5Crocidolite 12001-28-4Grunerite Asbestos (Amosite) 12172-73-5Anthophylli
20、te Asbestos 77536-67-5Tremolite Asbestos 77536-68-6Actinolite Asbestos 77536-66-43.1.3 fibrila single fiber that cannot be separated intosmaller components without losing its fibrous properties orappearance.3.2 Definitions of Terms Specific to This Standard:3.2.1 aspect ratiothe ratio of the length
21、of a fibrousparticle to its average width.3.2.2 bundlea structure composed of three or more fibersin a parallel arrangement with the fibers closer than one fiberdiameter to each other.3.2.3 clusteran aggregate of two or more randomly ori-ented fibers, with or without bundles. Clusters occur as twova
22、rietiesdisperse clusters and compact clusters.3.2.3.1 compact clustera complex and tightly bound net-work in which one or both ends of each individual fiber orbundle are obscured, such that the dimensions of individualfibers or bundles cannot be unambiguously measured.3.2.3.2 disperse clustera dispe
23、rse and open network inwhich both ends of one of the individual fibers or bundles canbe separately located and its dimensions measured.3.2.4 debrismaterials that are of an amount and size(particles greater than 1 mm in diameter as defined by a 1.0 by1.0 mm screen) that can be visually identified (by
24、 color,texture, etc.) as to their source.3.2.5 dustany material composed of particles in a sizerange of 1 mm.3.2.6 fibera structure having a minimum length of 0.5 mwith an aspect ratio of 5 to 1 or greater and substantiallyparallel sides (4). Fibers are assumed to have a cylindricalshape (5).3.2.7 f
25、ibrous minerala mineral that is composed of paral-lel, radiating, or interlaced aggregates of fibers, from which thefibers are sometimes separable.3.2.7.1 DiscussionThe crystalline aggregate may be re-ferred to as fibrous even if it is not composed of separablefibers, but has that distinct appearanc
26、e. The term fibrous is usedin a general mineralogical way to describe aggregates of grainsthat crystallize in a needle-like habit and appear to be com-posed of fibers. Fibrous has a much more general meaning thanasbestos. While it is correct that all asbestos minerals arefibrous, not all minerals ha
27、ving fibrous habits are asbestos.3.2.8 indirect preparationa method in which a samplepasses through one or more intermediate steps prior to finalfiltration.3.2.9 matrixa structure in which one or more fibers, orfiber bundles, touch, are attached to, or partially concealed bya single particle or conn
28、ected group of non-fibrous particles.The exposed fiber must meet the fiber definition (see section3.2.6). Matrices occur as two varietiesdisperse matrices andcompact matrices.3.2.9.1 compact matrixa structure consisting of a particleor linked group of particles, in which fibers or bundles can beseen
29、 either within the structure or projecting from it, such thatthe dimensions of individual fibers and bundles cannot beunambiguously determined.3.2.9.2 disperse matrixa structure consisting of a particleor linked group of particles, with overlapping or attached fibersor bundles in which at least one
30、of the individual fibers orbundles can be separately identified and its dimensions mea-sured.3.2.10 structuresa term that is used to categorize all thetypes of asbestos particles which are recorded during theanalysis (such as fibers, bundles, clusters, and matrices).4. Summary of Test Method4.1 The
31、sample is collected by vacuuming a known surfacearea with a standard 25 or 37 mm air sampling cassette usinga plastic tube that is attached to the inlet orifice which acts asa nozzle. The sample is transferred from inside the cassette toa 50/50 alcohol/water solution and screened through a 1.0 by1.0
32、 mm screen. The fine dust is filtered onto a membrane filterand ashed in a muffle furnace. The ash is mixed with distilledwater to a known volume. Aliquots of the suspension are thenfiltered through a membrane. A section of the membrane isprepared and transferred to a TEM grid using the direct trans
33、fermethod. The asbestiform structures are identified, sized, andcounted by TEM, using SAED and EDXA at a magnificationdependent on the size range of asbestos structures present.5. Significance and Use5.1 This microvacuum sampling and indirect analysismethod is used for the general testing of non-air
34、borne dustsamples for asbestos. It is used to assist in the evaluation ofdust that may be found on surfaces in buildings, such as ceilingtiles, shelving, electrical components, duct work, carpet, etc.This test method provides an estimate of the mass surfaceloading of asbestos in the dust reported as
35、 either the mass ofasbestos per unit area or as the mass of asbestos per mass ofsampled dust as derived from a quantitative TEM analysis.5.1.1 This test method does not describe procedures ortechniques required to evaluate the safety or habitability ofbuildings with asbestos-containing materials, or
36、 compliance4The boldface numbers refer to the list of references at the end of the testmethod.5The non-asbestiform variations of the minerals indicated in 3.1.2 have differentChemical Abstract Service (CAS) numbers.D5756022with federal, state, or local regulations or statutes. It is theusers respons
37、ibility to make these determinations.5.1.2 At present, no relationship has been established be-tween asbestos-containing dust as measured by this test methodand potential human exposure to airborne asbestos. Accord-ingly, the users should consider other available information intheir interpretation o
38、f the data obtained from this test method.5.2 This definition of dust accepts all particles small enoughto pass througha1mmscreen. Thus, a single, large asbestos-containing particle(s) (from the large end of the particle sizedistribution) disassembled during sample preparation mayresult in anomalous
39、ly large asbestos surface loading results inthe TEM analyses of that sample. Conversely, failure todisaggregate large particles may result in anomalously lowasbestos mass surface loadings. It is, therefore, recommendedthat multiple independent samples be secured from the samearea, and that a minimum
40、 of three samples be analyzed by theentire procedure.6. Interferences6.1 The following minerals have properties (that is, chemi-cal or crystalline structure) which are very similar to asbestosminerals and may interfere with the analysis by causing falsepositives to be recorded during the test. There
41、fore, literaturereferences for these materials must be maintained in thelaboratory for comparison to asbestos minerals so that they arenot misidentified as asbestos minerals.6.1.1 Antigorite.6.1.2 Palygorskite (Attapulgite).6.1.3 Halloysite.6.1.4 Pyroxenes.6.1.5 Sepiolite.6.1.6 Vermiculite scrolls.6
42、.1.7 Fibrous talc.6.1.8 Hornblende and other amphiboles not listed in 5.1.3.6.2 Collection of any dust particles greater than 1 mm insize in this test method may cause an interference and,therefore, should be avoided.7. Apparatus7.1 Transmission Electron Microscope (TEM),an80to120kV TEM, capable of
43、performing electron diffraction, with afluorescent screen inscribed with calibrated gradations, isrequired. The TEM must be equipped with energy dispersiveX-ray spectroscopy (EDXA) and it must have a scanningtransmission electron microscopy (STEM) attachment or becapable of producing a spot size of
44、less than 250 nm indiameter at crossover.7.2 Energy Dispersive X-ray System (EDXA).7.3 High Vacuum Carbon Evaporator, with rotating stage.7.4 High Effciency Particulate Air (HEPA), filtered nega-tive flow hood.7.5 Exhaust or Fume Hood.7.6 Particle-Free Water (ASTM Type II, see SpecificationD 1193).7
45、.7 Glass Beakers,50mL.7.8 Glass Sample Containers, with wide mouth screw cap(200 mL), or equivalent sealable container (height of the glasssample container should be approximately 13 cm high by 6 cmwide).7.9 Waterproof Markers.7.10 Forceps (tweezers).7.11 Ultrasonic Bath, table top model (100 W, app
46、roximate,see 22.5).7.12 Graduated Pipettes, 1, 5, and 10 mL sizes, glass orplastic.7.13 Filter Funnel, 25 mm or 47 mm (either glass ordisposable). Filter funnel assemblies, either glass or disposableplastic, and using either a 25 mm or 47 mm diameter filter.7.14 Side Arm Filter Flask, 1000 mL.7.15 M
47、ixed Cellulose Ester (MCE) Membrane Filters,25or47 mm diameter, #0.22 m and 5 m pore size.7.16 Polycarbonate (PC) Filters, 25 or 47 mm diameter,#0.2 m pore size.7.17 Storage Containers, for the 25 or 47 mm filters (forarchiving).7.18 Glass Slides.7.19 Scalpel Blades.7.20 Cabinet-type Desiccator, or
48、low temperature dryingoven.8. Reagents and Materials8.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless otherwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch spe
49、cifications are available.6Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity to permit its use without lessening the accuracy ofthe determination.8.2 Acetone.8.3 Dimethylformamide (DMF).8.4 Chloroform.8.5 1-methyl-2-pyrrolidone.8.6 Glacial Acetic Acid.8.7 Low Temperature Plasma Asher.8.8 pH Paper.8.9 Air Sampling Pump (low volume personal-type pump).8.10 Rotameter.8.11 Air Sampling Cassettes (25 mm or 37 mm), containing0.8 m or smaller pore size MCE or PC filters.8.12 Cork Borer, 7 mm.8.13 Non-Asbesto
