ASTM_D_4638_-_11.pdf

Designation:D463811Standard Guide forPreparation of Biological Samples for Inorganic ChemicalAnalysis1This standard is issued under the fixed designation D4638;the number immediately following the designation indicates the year oforiginal adoption or,in the case 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.Scope*1.1 This guide describes procedures for the preparation oftest samples collected from such locations as streams,rivers,ponds,lakes,estuaries,oceans,and toxicity tests and isapplicable to such organisms as plankton,mollusks,fish,andplants.1.2 The procedures are applicable to the determination ofvolatile,semivolatile,and nonvolatile inorganic constituents ofbiological materials.Analyses may be carried out or reportedon either a dry or wet basis.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included 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 use.For a specifichazard statement,see 9.3.3.2.Referenced Documents2.1 ASTM Standards:2D1129 Terminology Relating to WaterD1193 Specification for Reagent Water3.Terminology3.1 DefinitionsFor definitions of terms used in this guide,refer to Terminology D1129.4.Summary of Guide4.1 Samples are collected,where possible,with nonmetallicor TFE-fluorocarbon-coated sampling equipment to preventcontamination,stored in plastic containers,and kept either at4C or frozen until returned to an adequate facility for analysis.4.2 Before analysis,samples are allowed to return to roomtemperature.Large foreign objects are mechanically removedfrom the samples based upon visual examination;smallerforeign objects are also removed mechanically,with the aid ofa low-power microscope.4.3 Wet samples of small organisms such as plankton,aremixed for preliminary homogenization,then allowed to settle,to remove most of the occluded water.Larger organisms,suchas fish,should be patted dry,using paper towels.4.4 Where less than a whole organism is to be analyzed,tissue excisions are made with nonmetallic tools such as plasticknives or TFE-fluorocarbon-coated scalpels.4.5 Moisture determinations are made on separate samplesfrom those analyzed for volatile or semivolatile constituents.4.6 Analyses for volatile constituents are made using wetsamples from which supernatant liquid or occluded water hasbeen removed(see 4.3).The results may be calculated to thedry,original-sample basis,using the results of a moisturedetermination carried out on a separate sample.4.7 Analyses for semivolatile constituents are made on wetsamples or samples previously dried at a temperature(depen-dent on constituents of interest),or using a procedure,found tobe adequate for the purpose,and specified in the correspondinganalytical procedure.4.8 Analyses for nonvolatile constituents are made onsamples previously dried at a temperature(dependent onconstituents of interest),or using a procedure found to beadequate for the purpose,and specified in the correspondinganalytical procedure.4.9 Digest the samples according to the procedures outlinedin Section 9.4.10 A flow diagram outlining typical procedures is shownin Fig.1.5.Significance and Use5.1 The chemical analysis of biological material,collectedfrom such locations as streams,rivers,lakes,and oceans can1This guide is under the jurisdiction of ASTM Committee D19 on Water and isthe direct responsibility of Subcommittee D19.05 on Inorganic Constituents inWater.Current edition approved Sept.1,2011.Published September 2011.Originallyapproved in 1986.Last previous edition approved in 2007 as D4638 03(07).DOI:10.1520/D4638-11.2For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 provide information of environmental significance.The chemi-cal analysis of biological material used in toxicity tests may beuseful to better interpret the toxicological results.5.2 Many aquatic biological samples,either as a result oftheir size,or their method of collection,are inherently hetero-geneous in that they may contain occluded water in varyingand unpredictable amounts and may contain foreign objects ormaterial(for example,sediment)not ordinarily intended foranalysis,the inclusion of which would result in inaccurateanalysis.5.3 Standard methods for separating foreign objects,tofacilitate homogenization,will min