Determination of stereoisomer in sugars by THz-TDS
Determination of stereoisomer in sugars by THz-TDS
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THz-TDS 测定糖中的立体异构体
DOI：
10.1117/12.902044
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
M. Tonouchi
中科院分区：
文献类型：
--
作者：
S. Yamauchi;Y. Imai;H. Yokota;M. Tonouchi
在20°C、湿度低于5%的环境中，以飞秒光纤激光器为激发光源，采用LT-GaAs层上的偶极天线作为太赫兹发射器和检测器，建立了透射型太赫兹时域光谱（THz-TDS）测定糖立体异构体的方法。使用包含约4%端基异构体的市售α-D-乳糖和包含低于30%端基异构体的β-D-乳糖作为立体异构体样品。将不同配比的α-D-和β-D-乳糖粉末的吸收光谱依次用洛伦兹函数解卷积为4个光谱，并依赖于组成比。由于α-D-乳糖和β-D-乳糖的综合吸收决定了β-D-乳糖粉末组成比的下降速率（rα）和增加速率（rβ），因为强度与组成比呈线性关系。通过积分强度和rβ / rα值的比值，可以精确地计算出化合物中α-乳糖和β-乳糖的净组成比，例如，市售α-D-乳糖和β-D-乳糖粉末中的端基含量分别为3.9%和29.1%。实验结果表明，THz-TDS不仅可用于对乳糖等分子结构不同的糖的立体异构体进行精确的定性分析，而且可用于对乳糖等分子结构不同的糖的立体异构体进行精确的定量分析。
Transmission-type terahertz time-domain spectroscopy (THz-TDS) using dipole-antennas on LT-GaAs layers as THzemitter and detector with fs-fiber laser as the excitation light source was applied to determine the stereoisomer of sugars in carefully controlled environment with low humidity below 5% at 20°C. Commercially available α-D-lactose including about 4% anomer and β-D-lactose including below 30% anomer were used as stereoisomer samples. The absorption spectra of compounds by the α-D- and β-D-lactose powders with various ratios were successively deconvoluted to four spectra by Lorentzian and dependent on the composition ratio. Integrated absorptions due to α-D-lactose and β-D-lactose determined the decreasing rate (rα) and the increasing rate (rβ) for the composition ratio of the β-D-lactose powder, because the intensities were linearly dependent on the composition ratio. The net-composition ratio of α-lactose and β-lactose in the compounds was precisely evaluated by the ratio of the integrated intensities and the value of rβ / rα, for example, the anomer-contents in commercially available α-D-lactose and β-D-lactose powders were disclosed as 3.9% and 29.1%, respectively. The demonstrated results indicate that THz-TDS is so useful not only for precise qualitativeanalysis but also for precise quantitative-analysis of stereoisomer in sugars with partially different molecular structure such as lactose.
影响因子：
4
作者：
Yamaguchi, M;Miyamaru, F;Hangyo, M
通讯作者：
Hangyo, M