1、Designation:D501220Standard Practice forPreparation of Materials Used for the Collection andPreservation of Atmospheric Wet Deposition1This standard is issued under the fixed designation D5012;the number immediately following the designation indicates the year oforiginal adoption or,in the case of r
2、evision,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.Scope1.1 This practice presents recommendations for the cleaningof plastic or glass materials used for collectio
3、n of atmosphericwet deposition(AWD).This practice also presents recommen-dations for the preservation of samples collected for chemicalanalysis.1.2 The materials used to collectAWD for the analysis of itsinorganic constituents and trace elements should be plastic.High density polyethylene(HDPE)is mo
4、st widely used and isacceptable for most samples including samples for the deter-mination of the anions of acetic,citric,and formic acids.Borosilicate glass is a collection alternative for the determina-tion of the anions from acetic,citric,and formic acid;it isrecommended for samples for the determ
5、ination of otherorganic compounds.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 t
6、his standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Deci
7、sion on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1125 Test Methods for Electrical Conductivity a
8、nd Resis-tivity of WaterD1129 Terminology Relating to WaterD1193 Specification for Reagent WaterD1356 Terminology Relating to Sampling and Analysis ofAtmospheresD1695 Terminology of Cellulose and Cellulose Derivatives3.Terminology3.1 Definitions:3.1.1 For definitions of terms used in this practice,r
9、efer toTerminology D1129.3.1.2 For definition of plastic,refer to Terminology D1695and Terminology D883.3.1.3 For definition ofAWD(precipitation,meteorological),refer to Terminology D1356.4.Significance and Use4.1 Some chemical constituents of AWD are not stable andmust be preserved before chemical
10、analysis.Without samplepreservation,it is possible that analytes can be lost throughdecomposition or sorption to the storage bottles.4.2 Contamination of AWD samples can occur during bothsample preservation and sample storage.Proper selection andcleaning of sampling containers are required to reduce
11、 thepossibility of contamination of AWD samples.4.3 The natural sponge and talc-free plastic gloves used inthe following procedures should be recognized as potentialsources of contamination.Individual experience should beused to select products that minimize contamination.5.Apparatus5.1 Instruments
12、shall be selected in accordance with anapplicable test method given in Test Methods D1125.5.2 The conductivity cell shall be pipet or dip type with acell constant(K)of 0.1.6.Reagents and Materials6.1 Purity of ReagentsReagent grade acids and otherchemicals shall be used to reduce the risk of contami
13、nating theAWD samples.Unless otherwise indicated,it is intended that1This practice is under the jurisdiction ofASTM Committee D22 on Air Qualityand is the direct responsibility of Subcommittee D22.03 on Ambient Atmospheresand Source Emissions.Current edition approved Sept.1,2020.Published September
14、2020.Originallyapproved in 1989.Last previous edition approved in 2013 as D5012 01(2013).DOI:10.1520/D5012-20.2For 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 standar
15、ds Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on
16、 Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1all reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.36.2 Nitric acid,ultra pure.6.3 Nitric acid(1+9),dilute 1 volume concentrated nitricacid with 9 volumes of water.6.4 Chloroform,high performance liquid chromatographyreagent.6.5 H
