Bernard Sylvain, Beyssac Olivier, Benzerara Karim
Laboratoire de Géologie, Ecole Normale Supérieure, Paris, France.
Appl Spectrosc. 2008 Nov;62(11):1180-8. doi: 10.1366/000370208786401581.
By allowing nondestructive chemical and structural imaging of heterogeneous samples with a micrometer spatial resolution, Raman mapping offers unique capabilities for assessing the spatial distribution of both mineral and organic phases within geological samples. Recently developed line-scanning Raman mapping techniques have made it possible to acquire Raman maps over large, millimeter-sized, zones of interest owing to a drastic decrease of the data acquisition time without losing spatial or spectral resolution. The synchronization of charge-coupled device (CCD) measurements with x,y motorized stage displacement has allowed dynamic line-scanning Raman mapping to be even more efficient: total acquisition time may be reduced by a factor higher than 100 compared to point-by-point mapping. Using two chemically and texturally complex geological samples, a fossil megaspore in a metamorphic rock and aragonite-garnet intergrowths in an Eclogitic marble, we compare here two recent versions of line-scanning Raman mapping systems and discuss their respective advantages and disadvantages in terms of acquisition time, image quality, spatial and imaging resolutions, and signal-to-noise ratio. We show that line-scanning Raman mapping techniques are particularly suitable for the characterization of such samples, which are representative of the general complexity of geological samples.
通过对异质样品进行具有微米级空间分辨率的无损化学和结构成像，拉曼映射为评估地质样品中矿物相和有机相的空间分布提供了独特的能力。最近开发的线扫描拉曼映射技术使得在不损失空间或光谱分辨率的情况下，由于数据采集时间的大幅减少，能够在毫米级的大感兴趣区域上获取拉曼图。电荷耦合器件（CCD）测量与x、y电动平台位移的同步使得动态线扫描拉曼映射更加高效：与逐点映射相比，总采集时间可能会减少100倍以上。使用两个化学和结构复杂的地质样品，一个变质岩中的化石大孢子和一个榴辉岩大理岩中的文石-石榴石共生体，我们在此比较了两种最新版本的线扫描拉曼映射系统，并讨论了它们在采集时间、图像质量、空间和成像分辨率以及信噪比方面各自的优缺点。我们表明，线扫描拉曼映射技术特别适合于表征此类样品，这些样品代表了地质样品的一般复杂性。
