4.1 The structural carbohydrate content is used in conjunction with other assays to determine the total composition of biomass samples.

1.1 This test method describes the determination of structural carbohydrates present in a biomass sample, expressed as the percent mass of an oven-dried sample basis of each anhydrosugar.

1.2 Sample materials suitable for this procedure include hard and softwoods, herbaceous materials, such as sericea and switchgrass, agricultural residues, such as corn stover, wheat straw, and bagasse, wastepaper, such as boxboard, office waste, and newsprint, acid or alkaline-pretreated biomass, washed free of any residual acid or alkali, and the solid fraction of fermentation residues.

1.3 The options for the types of samples to be analyzed in this procedure are:

1.3.1 Prepared Biomass Samples: 

1.3.1.1 Air Dried Material—Results are reported as the percent by mass, based on the oven-dried mass of the air-dried sample.

1.3.1.2 45 °C Dried Material—Results are reported as the percent by mass, based on the oven-dried mass of the 45 °C dried sample.

1.3.1.3 Freeze Dried Material—Results are reported as the percent by mass, based on the oven-dried mass of the freeze dried sample.

1.3.2 Extractives-Free Sample—Results are reported as the percent by mass, based on the oven-dried mass of the extracted sample.

1.4 This standard method is generally not suitable for samples that contain soluble, nonstructural carbohydrates unless they are removed prior to analysis.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. See Section 8 for specific hazards statements.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.