1、Designation:D686612Standard Test Methods forDetermining the Biobased Content of Solid,Liquid,andGaseous Samples Using Radiocarbon Analysis1This standard is issued under the fixed designation D6866;the number immediately following the designation indicates the year oforiginal adoption or,in the case
2、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 These test methods do not address environmentalimpact,product performance and functionality,determ
3、inationof geographical origin,or assignment of required amounts ofbiobased carbon necessary for compliance with federal laws.1.2 These test methods are applicable to any product con-taining carbon-based components that can be combusted in thepresence of oxygen to produce carbon dioxide(CO2)gas.Theov
4、erall analytical method is also applicable to gaseoussamples,including flue gases from electrical utility boilers andwaste incinerators.1.3 These test methods make no attempt to teach the basicprinciples of the instrumentation used although minimumrequirements for instrument selection are referenced
5、 in theReferences section.However,the preparation of samples forthe above test methods is described.No details of instrumentoperation are included here.These are best obtained from themanufacturer of the specific instrument in use.1.4 Currently,there are no ISO test methods that areequivalent to the
6、 test methods outlined in this standard.1.5 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 lim
7、itations prior to use.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to Plastics3.Terminology3.1 The definitions of terms used in these test methods arereferenced in order that the practitioner may require furtherinformation regarding the practice of the art of isotope analysisa
8、nd to facilitate performance of these test methods.3.2 Terminology D883 should be referenced for terminol-ogy relating to plastics.Although an attempt to list terms in alogical manner(alphabetically)will be made as some termsrequire definition of other terms to make sense.3.3 Definitions:3.3.1 dpmdi
9、sintegrations per minute.This is the quantityof radioactivity.The measure dpm is derived from cpm orcounts per minute(dpm=cpm bkgd/counting efficiency).There are 2.2 by 106dpm/uCi(14,17).33.3.2 dpsdisintegrations per second(rather than minute asabove)(14,17).3.3.3 scintillationthe sum of all photons
10、 produced by aradioactive decay event.Counters used to measure this asdescribed in these test methods are Liquid Scintillation Coun-ters(LSC)(14,17).3.3.4 specific activity(SA)refers to the quantity of radio-activity per mass unit of product,that is,dpm per gram(14,17).3.3.5 automated effciency cont
11、rol(AEC)a method usedby scintillation counters to compensate for the effect ofquenching on the sample spectrum(14).3.3.6 AMS facilitya facility performing Accelerator MassSpectrometry.3.3.7 accelerator mass spectrometry(AMS)an ultra-sensitive technique that can be used for measuring naturallyoccurri
12、ng radio nuclides,in which sample atoms are ionized,accelerated to high energies,separated on basis of momentum,charge,and mass,and individually counted in Faraday collec-tors.This high energy separation is extremely effective infiltering out isobaric interferences,such thatAMS may be usedto measure
13、 accurately the14C/12C abundance to a level of 1 in1015.At these levels,uncertainties are based on countingstatistics through the Poisson distribution(8,9).3.3.8 background radiationthe radiation in the naturalenvironment;including cosmic radiation and radionuclides1These test methods are under the
14、jurisdiction of ASTM Committee D20 onPlastics and are the direct responsibility of Subcommittee D20.96 on Environmen-tally Degradable Plastics and Biobased Products.Current edition approved April 1,2012.Published May 2012.Originallyapproved in 2004.Last previous edition approved in 2011 as D6866-11.
15、DOI:10.1520/D6866-12.2For 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.3The boldface numbers in parentheses refer to
16、 the list of references at the end ofthis standard.*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 present in the local environment,for example,materials ofconstruction,metals,glass,concrete(2,4,7,8,14-19).3.3.9 biobased contentthe amount of biobased carbon inthe material or product as a percent of the weight(mass)of thetotal organic carbon in the product(1).3.3.10 coinc
