Department of Physics, College of Science, Swansea University, Singleton Park, Swansea, SA2 8PP United Kingdom.
Appl Spectrosc. 2013 Aug;67(8):949-59. doi: 10.1366/12-06766.
An integrated concept for post-acquisition spectrum analysis was developed for in-line (real-time) and off-line applications that preserves absolute spectral quantification; after the initializing parameter setup, only minimal user intervention is required. This spectral evaluation suite is composed of a sequence of tasks specifically addressing cosmic ray removal, background subtraction, and peak analysis and fitting, together with the treatment of two-dimensional charge-coupled device array data. One may use any of the individual steps on their own, or may exclude steps from the chain if so desired. For the background treatment, the canonical rolling-circle filter (RCF) algorithm was adopted, but it was coupled with a Savitzky-Golay filtering step on the locus-array generated from a single RCF pass. This novel only-two-parameter procedure vastly improves on the RCF's deficiency to overestimate the baseline level in spectra with broad peak features. The peak analysis routine developed here is an only-two-parameter (amplitude and position) fitting algorithm that relies on numerical line shape profiles rather than on analytical functions. The overall analysis chain was programmed in National Instrument's LabVIEW; this software allows for easy incorporation of this spectrum analysis suite into any LabVIEW-managed instrument control, data-acquisition environment, or both. The strength of the individual tasks and the integrated program sequence are demonstrated for the analysis of a wide range of (although not necessarily limited to) Raman spectra of varying complexity and exhibiting nonanalytical line profiles. In comparison to other analysis algorithms and functions, our new approach for background subtraction, peak analysis, and fitting returned vastly improved quantitative results, even for "hidden" details in the spectra, in particular, for nonanalytical line profiles. All software is available for download.
开发了一种用于在线（实时）和离线应用的采集后谱分析的集成概念，该概念保留了绝对光谱定量；在初始参数设置后，仅需要最少的用户干预。该光谱评估套件由一系列任务组成，专门用于解决宇宙射线去除、背景减除和峰分析与拟合，以及二维电荷耦合器件阵列数据的处理。用户可以单独使用任何一个步骤，也可以根据需要从链中排除步骤。对于背景处理，采用了典型的滚动圆滤波器（RCF）算法，但它与在单个 RCF 通过生成的轨迹-数组上的 Savitzky-Golay 滤波步骤耦合。这种新颖的仅两个参数的方法极大地改善了 RCF 在具有宽峰特征的光谱中高估基线水平的缺陷。这里开发的峰分析例程是一种仅两个参数（幅度和位置）拟合算法，它依赖于数值线形状轮廓而不是分析函数。整个分析链在 National Instrument 的 LabVIEW 中编程；该软件允许将此光谱分析套件轻松集成到任何由 LabVIEW 管理的仪器控制、数据采集环境或两者中。该程序的各个任务和集成程序序列的强度通过对各种（尽管不一定限于）具有不同复杂性的拉曼光谱的分析得到了证明，这些光谱的线轮廓是非分析性的。与其他分析算法和功能相比，我们的新背景减除、峰分析和拟合方法即使对于光谱中的“隐藏”细节，特别是对于非分析性线轮廓，也能返回大大改善的定量结果。所有软件均可下载。
