Near-infrared-Fourier-transform-Raman microspectroscopic imaging of flax stems
Near-infrared-Fourier-transform-Raman microspectroscopic imaging of flax stems
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DOI：
10.1016/s0924-2031(98)00065-4
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发表时间：
1999-04-01
影响因子：
2.5
通讯作者：
Akin, DE
中科院分区：
文献类型：
--
作者：
Himmelsbach, DS;Khahili, S;Akin, DE
利用近红外傅里叶变换拉曼（NIR-FT-拉曼）显微镜对亚麻（Linum usitatissimum，nan L.）茎组织将亚麻的厚（类似于80 μ m）横截面冷冻切片，解冻，在85%RH下平衡>3小时，并密封在金镜显微镜载玻片上的盖玻片下。每个图像像素的光谱是在16 cm（-1）处的拉曼位移区域3600-300 cm（-1）上从选定的组织切片收集的，扫描256-512次，并在样品处使用类似于185 mW的聚焦激光功率。使用计算机控制的自动显微镜载物台以6-10 μ m的步长收集矩形尺寸的50-150 μ m的区域图，并将它们与使用CCD相机捕获的可见图像配准。每个图像的数据收集需要8-10小时。化学配置文件是从特定光谱区域的面积积分。化学配置文件显示了亚麻的解剖细胞类型的所有主要成分的位置。CH拉伸区域2850 cm（-1）处的尖肩提供了表皮/表皮组织中蜡的证据。在1600 cm（-1）附近出现的谱带，是由于芳香环的伸缩振动，证明了核心组织中的木质素和表皮组织中的色素。由于COC重原子混合模式振动，出现在1175-1050 cm（-1）之间的谱带显示纤维细胞中碳水化合物浓度最高，核心组织中碳水化合物含量较低（但很重要）。此外，出现在870-800、515-476和400-360 cm（-1）之间的条带分别为薄壁组织中果胶、其他非纤维素多糖和纤维素的存在提供了具体证据。出版社：Elsevier Science B. V.
Near-infrared-Fourier-transform-Raman (NIR-FT-Raman) microscopy was employed to image and subsequently produce in situ maps of the distribution of chemical components in flax (Linum usitatissimum,nan L.) stem tissue. Thick(similar to 80 mu m) cross-sections of flax were cryotomed, thawed, equilibrated at 85% RH for >3 h and sealed under cover glasses on gold-mirrored microscope slides. Spectra for each image pixel were collected from selected tissue sections over the Raman shifted region 3600-300 cm(-1) at 16 cm(-1) with 256-512 scans and employing similar to 185 mW of focused laser power at the sample. A computer controlled automated microscope stage was used to collect area maps of 50-150 mu m in rectangular dimensions in 6-10 mu m steps and register them to the visible images that were captured using a CCD camera. Data collection required 8-10 h per image. Chemical profiles were produced from area integrations of specific spectral regions. The chemical profiles showed the location of all of the major components of flax by anatomical cell type. A sharp shoulder at 2850 cm(-1) in the CH stretch region provided evidence of waxes in the cuticular/epidermal tissue. The bands occurring around 1600 cm(-1), due to aromatic ring stretching vibrations, gave evidence of lignin in core tissue and pigments in epidermal tissue. Bands occurring between 1175-1050 cm(-1), due to COC heavy atom mixed mode vibrations, showed the greatest concentration of carbohydrate in fiber cells with lesser (but significant) amounts indicated in core tissue. In addition, bands occurring between 870-800, 515-476 and 400-360 cm(-1) gave specific evidence for the presence of pectins, other non-cellulosic polysaccharides and cellulose, respectively, in parenchyma tissue. Published by Elsevier Science B.V.