Kiefer Johannes, Obert Katharina, Fries Jürgen, Bösmann Andreas, Wasserscheid Peter, Leipertz Alfred
Lehrstuhl für Technische Thermodynamik and Erlangen Graduate School in Advanced Optical Technologies, Universität Erlangen-Nürnberg, Am Weichselgarten 8, D-91058 Erlangen, Germany.
Appl Spectrosc. 2009 Sep;63(9):1041-9. doi: 10.1366/000370209789379367.
The conversion of biogenic carbohydrate feedstock to chemicals or energy equivalents is a promising approach to solve the problem of limited fossil fuel reserves. Some concepts to accomplish these transformations are based on ionic liquids (ILs) due to their ability to dissolve biopolymers, such as cellulose, and even complex biopolymer mixtures, such as wood. However, concerning control of such conversions, a reliable tool for process analytics is required. In this paper we demonstrate the applicability of Fourier transform infrared (FT-IR) spectroscopy to perform quantitative concentration measurements of glucose and cellobiose as two examples of carbohydrates dissolved in the room-temperature ionic liquid [EMIM][OAc] (1-ethyl-3-methylimidazolium acetate). For this purpose, binary mixtures in the range 0-20 wt% have been studied. A previously developed method for the data analysis, which was based on the Beer-Lambert relation, has been universalized by employing empirical correlations between the measured quantity (i.e., extinction) and the carbohydrate concentration. In the entire spectral range under investigation (500-4000 cm(-1)) numerous individual wave-numbers have been identified, allowing quantitative measurements with high accuracy and precision.
将生物源碳水化合物原料转化为化学品或能量等价物是解决化石燃料储备有限问题的一种很有前景的方法。由于离子液体（ILs）能够溶解生物聚合物（如纤维素）甚至复杂的生物聚合物混合物（如木材），因此实现这些转化的一些概念是基于离子液体的。然而，关于此类转化的控制，需要一种可靠的过程分析工具。在本文中，我们展示了傅里叶变换红外（FT-IR）光谱法用于对溶解在室温离子液体[EMIM][OAc]（1-乙基-3-甲基咪唑鎓乙酸盐）中的两种碳水化合物葡萄糖和纤维二糖进行定量浓度测量的适用性。为此，研究了0-20 wt%范围内的二元混合物。一种先前开发的基于比尔-朗伯关系的数据分析方法，通过采用测量量（即吸光度）与碳水化合物浓度之间的经验相关性而得到了推广。在所研究的整个光谱范围（500-4000 cm(-1)）内，已识别出许多单个波数，从而能够进行高精度和高准确度的定量测量。
