1、Designation: D6323 12Standard Guide forLaboratory Subsampling of Media Related to WasteManagement Activities1This standard is issued under the fixed designation D6323; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t 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 guide covers common techniques for obtainingrepresentative subsamples from a sample received at a labora-tory for an
3、alysis. These samples may include solids, sludges,liquids, or multilayered liquids (with or without solids).1.2 The procedures and techniques discussed in this guidedepend upon the sample matrix, the type of sample preparationand analysis performed, the characteristic(s) of interest, and theproject
4、specific instructions or data quality objectives.1.3 This guide includes several sample homogenizationtechniques, including mixing and grinding, as well as informa-tion on how to obtain a specimen or split laboratory samples.1.4 This guide does not apply to air or gas sampling.1.5 The values stated
5、in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.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 establish appro-priate safety and he
6、alth practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C702 Practice for Reducing Samples ofAggregate to TestingSizeC859 Terminology Relating to Nuclear MaterialsD346 Practice for Collection and Preparation of CokeSamples for
7、 Laboratory AnalysisD2234/D2234M Practice for Collection of a Gross Sampleof CoalD4547 Guide for Sampling Waste and Soils for VolatileOrganic CompoundsD4823 Guide for Core Sampling Submerged, Unconsoli-dated SedimentsD5681 Terminology for Waste and Waste ManagementD5743 Practice for Sampling Single
8、or MultilayeredLiquids, With or Without Solids, in Drums or SimilarContainersD5792 Practice for Generation of Environmental Data Re-lated to Waste Management Activities: Development ofData Quality ObjectivesD5956 Guide for Sampling Strategies for HeterogeneousWastesD6051 Guide for Composite Sampling
9、 and Field Subsam-pling for Environmental Waste Management Activities3. Terminology3.1 DefinitionsFor definitions of terms used in this guide,refer to Terminology D5681.3.2 Definitions of Terms Specific to This Standard:3.2.1 contaminant unit, nthe largest particle size thatcontains the contaminant
10、of interest3.2.1.1 DiscussionThe contaminant of concern, as definedby the project objectives, may be associated with all theparticle sizes or associated with only a certain particle size orsizes. At the time of waste generation, discharge or spill, theparticle size of this contaminant of concern may
11、 be on theatomic or molecular scale, such as solvent spill into sand, or amacro scale, such as lead acid batteries at a dump site. Thecontaminant unit may also be in-between these scales, such aslead particles encapsulated in coal. In practice, the contaminantunit may change if the contaminant unit
12、becomes absorbed oradsorbed to particles larger than the contaminant unit. It is thesize of the contaminant unit at the time of subsampling, not atthe time of generation, that is referred to as the contaminantunit.3.2.2 maximum allowable particle size, nthe largest linealdimension of a samples indiv
13、idual particles accepted for agiven sample mass.3.2.2.1 DiscussionThe maximum allowable particle sizeis sometimes referred to as the allowable particle size.Asimplemethod of measurement is a sieve.1This test method is under the jurisdiction of ASTM Committee D34 on WasteManagement and is the direct
14、responsibility of Subcommittee D34.01.01 onPlanning for Sampling.Current edition approved Nov. 1, 2012. Published December 2012. Originallyapproved in 1998. Last previous edition approved in 2003 as D6323 98 (2003),which was withdrawn in June 2012 and reinstated in August 2012. DOI: 10.1520/D6323-12
15、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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C
16、700, West Conshohocken, PA 19428-2959. United States13.2.3 multilayered sample, na sample consisting of two ormore clearly differentiated components.3.2.3.1 DiscussionMultilayered samples are those withtwo or more distinct visual layers of material. These layers maybe the result of differences in de
17、nsity, such as liquid/liquidlayers (for example, chlorinated solvents and water, water andoil), liquid/solid layers (for example, sludge), solid/solid layers(for example, small rocks and large rocks), or combinations ofthese layers (for example water, oil, and soil). These layersmay also be the resu
18、lt of depositional layering, such as greenclay and silty sand from a coring sample.3.2.4 particle size, nthe controlling lineal dimension ofindividual particles (see Terminology C859).3.2.5 representative subsample, na subsample collected insuch a manner that it reflects one or more characteristics
19、ofinterest (as defined by the project objectives) of the laboratorysample from which it was collected.3.2.5.1 DiscussionA representative subsample can applyto a single sample, or a composite sample.3.2.6 sludge, nAny mixture of solids that settles out ofsolution. Sludges contain liquids that are not
20、 apparent as freeliquids, (see Practice D5743).4. Significance and Use4.1 This guide discusses options for taking a subsamplefrom a sample submitted to a laboratory. If followed, it willminimize the bias and variance of the characteristic of interestof the laboratory sample prior to analysis.4.2 The
21、 guide will describe appropriate instructions to besubmitted to the laboratory with the field sample.4.3 This guide is intended for use in the laboratory to take arepresentative subsample or specimen of the whole fieldsample for direct analysis or sample preparation for analysis. Itis intended for f
22、ield personnel, data users, laboratory samplereception personnel, analysts, and managers.4.4 To obtain a representative subsample, layer analysis,grinding, mixing, and changing the physical state such asdigesting, drying, melting or freezing may be required. Thisguide considers cone and quartering,
23、riffle splitting, andparticle size reduction.5. General Considerations5.1 Successful implementation of this standard depends oneffective communication between the data user and the labo-ratory staff. The selection of optimal subsampling procedures,techniques, and strategy by the laboratory depends o
24、n theintended use of the data. The data user should submit appro-priate instructions with all samples and, when necessary, thelaboratory staff should contact the data user for confirmation orfurther clarification of these instructions.5.1.1 The appropriate instructions must be reviewed by boththe la
25、boratory receiving personnel and the analyst(s) or super-visor. If there are no instructions, the appropriate laboratorypersonnel should contact the data user. Options should bediscussed and clarified prior to initiating any subsamplingprocedure. These instructions may include such options asthose f
26、ound in Table 1. The limitations and advantages of thesemethods are also found in this table. The data user should beinformed about the limitations and advantages of all subsam-pling procedures prior to deciding which one to use.5.1.2 If the data user still provides no instructions uponbeing contact
27、ed, laboratory personnel should explain to thedata user that the laboratorys standard operating procedures,which reflect the concerns and issues discussed in thisstandard, will be used. The sample should be treated as if thescale of the contamination is on the micro level, and noartifacts can be rem
28、oved. Since sample matrices and types andmechanisms of contamination are infinitely variable and re-quire judgments to be made, it is advisable that experiencedanalysts decide which subsampling techniques be employed.These procedures must be discussed and clarified with the datauser prior to initiat
29、ing any subsampling procedure.5.2 If the sample integrity or composition is not asanticipated, the data user must be contacted to confirm orclarify the instructions. An example of when this would benecessary would be a case where a coring sleeve was receivedat the laboratory. On opening the containe
30、r, the analyst noticesclay in one end of the sleeve, and sand at the other end. Beforethe analyst can proceed, the appropriate instructions from thedata user must be obtained.5.2.1 Field samples should be collected in appropriatecontainers for the analyses requested. If the submitted sampleis improp
31、erly collected, the data user should be contacted bylaboratory personnel. If the data user authorizes the laboratoryto continue with the analysis, a note should be made in thereceival documentation, and also in the case narrative in thefinal report.5.3 Documentation during the subsampling process is
32、 criti-cal. Since subsampling techniques may bias the results, thesubsampling method used must be noted in the analyticallogbook.5.3.1 Anytime the analytical result will be biased, it must bedocumented, and the data user should be notified prior tobeginning any subsampling technique. For example, if
33、 head-space exists in a container arriving at the laboratory, somevolatile components will have partitioned into that headspace.However, if the data user decides to proceed with the analysis,the analytical logbook and the case narrative on the final reportshould indicate this condition.5.4 Particle
34、size is the physical dimension of an objectspieces or parts. The maximum particle size contained within alaboratory sample is the largest of these pieces. The contami-nant of concern, as defined by the project objectives, may beassociated with all particle sizes or associated with only acertain part
35、icle size or sizes. The largest of these particle sizes,that contain the contaminant of interest, would be the contami-nant unit. The contaminant unit, at the time of wastegeneration, discharge or spill, may be on the atomic ormolecular scale, such as a solvent spill into sand, or a macroscale, such
36、 as lead acid batteries at a dump site. The contami-nant unit may also be in-between these scales, such as leadparticles encapsulated in coal. In practice, the contaminant unitmay change if the contaminant becomes absorbed or adsorbedto particles larger than the contaminant unit.D6323 1225.4.1 Knowl
37、edge of the contaminant unit may be used todetermine the preliminary steps to subsampling. For example,if the contaminant unit is on a molecular scale and wasadsorbed to soil particles and rocks, removal of large rockswith their relatively small surface area may not affect the dataas long as the res
38、ults are weight averaged. If one is unsure ofthe mechanism of contamination, that determines how thecontamination is dispersed within the sample matrix, one maynot be able to discard any particles during subsampling.5.5 Sampling theory requires that subsample mass shouldincrease as the size of the l
39、argest particle in the sampleincreases. If the subsample mass recommended by samplingtheory is larger than that normally used in the sample prepa-ration method, the subsample mass may be increased and theextraction/digestion procedure scaled accordingly. The stan-dard volume of digestate/extract is
40、then submitted for analysis.However, if the subsample mass is too large to be accommo-dated by the sample preparation procedure, multiple sub-samples (of equal mass) can be extracted/digested, and theextracts/digests combined and mixed prior to removal of thestandard volume specimen needed for analy
41、sis. Another alter-native is to reduce the particle size of the entire sample orsubsample as specified by sampling theory. If the particle sizeis reduced enough, a subsample of the mass recommended bysampling theory and the extraction/digestion method can beobtained.5.6 All subsampling should be per
42、formed in an area whichis free from contamination, easily decontaminated, and ventedto control dust and remove fumes.5.7 Prior to subsampling liquids, the analyst must considerthe property or characteristic requested, and the container sizereceived. If the analyte has the ability to adsorb onto thec
43、ontainer, the field sample should arrive at the laboratory in anappropriately sized bottle, such that the whole sample will beused. The sides of the container should then be rinsed properlyto assure that all the contaminants are transferred into theanalytical vessel.5.8 Subsampling techniques are di
44、fferent when analyzingfor volatile compounds than non-volatile compounds. Thedifferences are discussed for each sample matrix.6. Matrix Specific Subsampling6.1 Solids:TABLE 1 Limitations and Advantages of Sample Preparation OptionsInstruction Limitations AdvantagesRemove artifacts, such as rocks and
45、 twigs, from thesample prior to subsampling(1) May bias analytical results by altering contaminantconcentration, (2) May bias sample if results are notproperly weight averaged.(1) May be easier to subsample, (2) May be easier toanalyze, (3) Appropriate if the target population ismaterial minus artif
46、acts.Digest or extract the contaminant from the outsideof the large particlesMay bias sample if contaminant is within the largeparticles.A(1) May be easier to analyze, (2) May prevent needfor weight average calculation.Digest or extract particle sizes separately (1) Separation of particle sizes may
47、be difficult,A(2) May bias sample if results are not properly weightaveraged, (3) Higher cost.(1) Allows some particle size consistency duringanalysis, (2) May be easier to subsample withinportions after separation.Form an emulsion layer so that the material maybe treated as homogeneous liquidMay bi
48、as the sample if a complete emulsion is notachieved.A(1) May be easier to subsample as a homogeneousliquid,Separate liquid layers (1) Separation of layers may be difficult, especiallyat the interface, (2) May bias sample if results arenot properly weight averaged.(1) May be easier to analyze, (2) Ma
49、y be easier tosubsample within portions after separation, (3) Allowsdifferent preparation methods within each layer.Dry sample May alter chemistry or change stability of somecompounds.A(1) Allows for consistency of subsampling for liquid/solid mixtures, (2) Analytes reported unbiased bymoisture content.Change the physical state, such as freeze thematerial so that it may be treated as a solid, ormelt the material so that it may be treated as aliquidMay be difficult to achieve complete freezing ormelting and maintain it long enough to get asubsample.AAllows for consisten
