ASTM_E_1821_-_08_2015.pdf

Designation:E182108(Reapproved 2015)Standard Test Method forDetermination of Carbohydrates in Biomass by GasChromatography1This standard is issued under the fixed designation E1821;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.INTRODUCTIONThis test method gives a reproducible way to quantitatively determine in lignocellulosic materialsthe kind and amount of the structural carbohydrates made from arabinose,xylose,mannose,galactose,and glucose.This way is accomplished by first hydrolyzing the carbohydrates to their constituentmonosaccharides.Subsequent derivatization produces the corresponding alditol acetates that arequantified using capillary gas chromatography.1.Scope1.1 This test method describes the determination of struc-tural carbohydrates present in a biomass sample,expressed asthe percent mass of an oven-dried sample basis of eachanhydrosugar.1.2 Sample materials suitable for this procedure includehard and softwoods,herbaceous materials,such as sericea andswitchgrass,agricultural residues,such as corn stover,wheatstraw,and bagasse,wastepaper,such as boxboard,office waste,and newsprint,acid or alkaline-pretreated biomass,washedfree of any residual acid or alkali,and the solid fraction offermentation residues.1.3 The options for the types of samples to be analyzed inthis procedure are:1.3.1 Prepared Biomass Samples:1.3.1.1 Air Dried MaterialResults are reported as thepercent by mass,based on the oven-dried mass of the air-driedsample.1.3.1.2 45C Dried MaterialResults are reported as thepercent by mass,based on the oven-dried mass of the 45Cdried sample.1.3.1.3 Freeze Dried MaterialResults are reported as thepercent by mass,based on the oven-dried mass of the freezedried sample.1.3.2 Extractives-Free SampleResults are reported as thepercent by mass,based on the oven-dried mass of the extractedsample.1.4 This standard method is generally not suitable forsamples that contain soluble,nonstructural carbohydrates un-less they are removed prior to analysis.1.5 The values stated 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 health practices and determine the applica-bility of regulatory limitations prior to use.See Section 8 forspecific hazards statements.2.Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterE1690 Test Method for Determination of Ethanol Extrac-tives in BiomassE1721 Test Method for Determination of Acid-InsolubleResidue in BiomassE1756 Test Method for Determination of Total Solids inBiomassE1757 Practice for Preparation of Biomass for Composi-tional Analysis3.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 anhydrosugars,nthe nominal repeating unit of apolysaccharide.Whenpolysaccharidesundergoacid1This test method is under the jurisdiction of ASTM Committee E48 onBioenergy and Industrial Chemicals from Biomass and is the direct responsibility ofSubcommittee E48.05 on Biomass Conversion.Current edition approved June 1,2015.Published July 2015.Originally approvedin 1996.Last previous edition approved in 2008 as E1821-08.DOI:10.1520/E1821-08R15.2For 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 C700,West Conshohocken,PA 19428-2959.United States1 hydrolysis,each repeating unit adds a single molecule of waterto form the free monosaccharide that is analyzed.The extraweight from this water of hydrolysis must be taken in toaccount whencalculating the actual mass percent of the poly-saccharide in the original biomass sample.3.1.2 as received biomass,nmaterial as it is received in itsfield or process collected state.3.1.3 extractives-free biomassair-dried solids left afterbiomass has been treated according to Test Method E1690.3.1.4 oven-dried mass,nthe moisture-free mass of anybiomass sample(as received,prepared,extractives-free,etc.)dried at 105C as described in Test Method E1756.3.1.5 prepared biomass,nas received biomass materialthat has been treated according to Practice E1757 in order toraise the total solids content above 85%,based on an oven-dried solids weight.3.1.6 structural carbohydrates,npolysaccharides thatcannot be removed by extraction with solvents and are liber-ated from the biomass solids with dilute acid hydrolysis.Forthe purpose of this test method,the monosaccharides that areconsidered present are arabinose,xylose,ma