Automatic Baseline Subtraction of Vibrational Spectra Using Minima Identification and Discrimination via Adaptive, Least-Squares Thresholding
Abstract:A method of automated baseline correction has been developed and applied to Raman spectra with a low signal-to-noise ratio and surface-enhanced infrared absorption (SEIRA) spectra with bipolar bands. Baseline correction is initiated by dividing the raw spectrum into equally spaced segments in which regional minima are located. Following identification, the minima are used to generate an intermediate second-derivative spectrum where points are assigned as baseline if they reside within a locally defined threshold region. The threshold region is similar to a confidence interval encountered in statistics. To restrain baseline and band point discrimination to the local level, the calculation of the confidence region employs only a predefined number of already-accepted baseline minima as part of the sample set. Statistically based threshold criteria allow the procedure to make an unbiased assessment of baseline points regardless of the behavior of vibrational bands. Furthermore, the threshold region is adaptive in that it is further modified to consider abrupt changes in baseline. The present procedure is model-free insofar as it makes no assumption about the precise nature of the perturbing baseline nor requires treatment of spectra prior to execution.
Document Type: Research Article
Affiliations: Department of Chemical and Materials Engineering, University of Idaho, PO Box 441021, Moscow, Idaho 83844-1021, USA
Publication date: May 1, 2012
More about this publication?
- The Society publishes the internationally recognized, peer reviewed journal, Applied Spectroscopy, which is available both in print and online. Subscriptions are included with membership or can be purchased by institutional or corporate organizations. Abstracts may be viewed free of charge. Previously published as Bulletin (Society for Applied Spectroscopy)
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Request copyrighted SAS materials
- Spectroscopic Nomenclature
- Focal Point (Open Access)
- ingentaconnect is not responsible for the content or availability of external websites