Biomass compositional methods are used to compare different lignocellulosic feedstocks, to measure component balances around unit operations and to determine process yields and therefore the economic viability of biomass-to-biofuel processes. Four biomass reference materials (RMs NIST 8491–8494) were prepared and characterized, via an interlaboratory comparison exercise in the early 1990s to evaluate biomass summative compositional methods, analysts, and laboratories. Having common, uniform, and stable biomass reference materials gives the opportunity to assess compositional data compared to other analysts, to other labs, and to a known compositional value. The expiration date for the original characterization of these RMs was reached and an effort to assess their stability and recharacterize the reference values for the remaining material using more current methods of analysis was initiated. We sent samples of the four biomass RMs to 11 academic, industrial, and government laboratories, familiar with sulfuric acid compositional methods, for recharacterization of the component reference values. In this work, we have used an expanded suite of analytical methods that are more appropriate for herbaceous feedstocks, to recharacterize the RMs’ compositions. We report the median values and the expanded uncertainty values for the four RMs on a dry-mass, whole-biomass basis. The original characterization data has been recalculated using median statistics to facilitate comparisons with this data. We found improved total component closures for three out of the four RMs compared to the original characterization, and the total component closures were near 100 %, which suggests that most components were accurately measured and little double counting occurred. The major components were not statistically different in the recharacterization which suggests that the biomass materials are stable during storage and that additional components, not seen in the original characterization, were quantified here.

中文翻译：

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生物量标准物质的成分分析：实验室间研究的结果。

生物质组成方法用于比较不同的木质纤维素原料，测量单元操作周围的组分平衡，并确定过程的收率，从而确定生物质转化为生物燃料过程的经济可行性。通过1990年代初期的实验室间比较演习，准备并表征了四种生物质参考材料（RMs NIST 8491–8494），以评估生物质总和组成方法，分析人员和实验室。与其他分析师，其他实验室和已知的成分值相比，拥有通用，统一和稳定的生物质参考材料可提供评估成分数据的机会。这些RM的原始表征已到期，并开始使用最新的分析方法来评估其稳定性并重新表征其余材料的参考值。我们将四个生物质RM的样品发送到了11个学术，工业和政府实验室，这些实验室熟悉硫酸的组成方法，以重新表征组分的参考值。在这项工作中，我们使用了扩展的分析方法套件，这些方法更适合于草本原料，以表征RM的组成。我们以干质量，全生物量为基础报告了四个RM的中值和扩展的不确定性值。原始特征数据已使用中位数统计数据重新计算，以便于与此数据进行比较。我们发现，与原始特征相比，四个RM中的三个RM的总组件封闭度有所改善，并且总组件封闭度接近100％，这表明大多数组件都经过了精确测量，几乎没有重复计数。在重新表征中，主要成分在统计学上没有差异，这表明生物质材料在储存过程中是稳定的，并且在此处对原始特征中未发现的其他成分进行了定量。