Department of Chemistry, University of Louisville, Louisville, KY 40292, USA.
J Chromatogr A. 2013 Jul 12;1298:132-8. doi: 10.1016/j.chroma.2013.05.021. Epub 2013 May 13.
Compound identification in gas chromatography-mass spectrometry (GC-MS) is usually achieved by matching query spectra to spectra present in a reference library. Although several spectral similarity measures have been developed and compared using a small reference library, it still remains unknown how the relationship between the spectral similarity measure and the size of reference library affects on the identification accuracy as well as the optimal weight factor. We used three reference libraries to investigate the dependency of the optimal weight factor, spectral similarity measure and the size of reference library. Our study demonstrated that the optimal weight factor depends on not only spectral similarity measure but also the size of reference library. The mixture semi-partial correlation measure outperforms all existing spectral similarity measures in all tested reference libraries, in spite of the computational expense. Furthermore, the accuracy of compound identification using a larger reference library in future is estimated by varying the size of reference library. Simulation study indicates that the mixture semi-partial correlation measure will have the best performance with the increase of reference library in future.
在气相色谱-质谱联用仪（GC-MS）中，化合物的鉴定通常是通过将查询谱图与参考库中存在的谱图进行匹配来实现的。尽管已经开发并比较了几种光谱相似性度量方法，并使用了一个小型参考库，但仍然不知道光谱相似性度量与参考库大小之间的关系如何影响鉴定的准确性以及最佳权重因素。我们使用了三个参考库来研究最佳权重因素、光谱相似性度量和参考库大小之间的依赖性。我们的研究表明，最佳权重因素不仅取决于光谱相似性度量，还取决于参考库的大小。混合半偏相关度量在所有测试的参考库中都优于所有现有的光谱相似性度量，尽管计算成本较高。此外，通过改变参考库的大小来估计未来使用更大的参考库进行化合物鉴定的准确性。模拟研究表明，随着未来参考库的增加，混合半偏相关度量将具有最佳的性能。
