title: Application of fast Fourier transform cross-correlation and mass spectrometry data for accurate alignment of chromatograms.
abstract: Chromatography has been established as one of the most important analytical methods in the modern analytical laboratory. However, preprocessing of the chromatograms, especially peak alignment, is usually a time-consuming task prior to extracting useful information from the datasets because of the small unavoidable differences in the experimental conditions caused by minor changes and drift. Most of the alignment algorithms are performed on reduced datasets using only the detected peaks in the chromatograms, which means a loss of data and introduces the problem of extraction of peak data from the chromatographic profiles. These disadvantages can be overcome by using the full chromatographic information that is generated from hyphenated chromatographic instruments. A new alignment algorithm called CAMS (Chromatogram Alignment via Mass Spectra) is present here to correct the retention time shifts among chromatograms accurately and rapidly. In this report, peaks of each chromatogram were detected based on Continuous Wavelet Transform (CWT) with Haar wavelet and were aligned against the reference chromatogram via the correlation of mass spectra. The aligning procedure was accelerated by Fast Fourier Transform cross correlation (FFT cross correlation). This approach has been compared with several well-known alignment methods on real chromatographic datasets, which demonstrates that CAMS can preserve the shape of peaks and achieve a high quality alignment result. Furthermore, the CAMS method was implemented in the Matlab language and available as an open source package at http://www.github.com/matchcoder/CAMS.
authors.affiliation: College of Chemistry and Chemical Engineering, Research Center of Modernization of Chinese Medicines, Central South University, Changsha 410083, China.
authors.forename: Yi-Bao
authors.initials: YB
authors.lastname: Zheng
authors.forename: Zhi-Min
authors.initials: ZM
authors.lastname: Zhang
authors.forename: Yi-Zeng
authors.initials: YZ
authors.lastname: Liang
authors.forename: De-Jian
authors.initials: DJ
authors.lastname: Zhan
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Huang
authors.forename: Yong-Huan
authors.initials: YH
authors.lastname: Yun
authors.forename: Hua-Lin
authors.initials: HL
authors.lastname: Xie
mesh_terms: D000465:Algorithms; D000818:Animals; D003198:Computer Simulation; D016208:Databases, Factual; D005583:Fourier Analysis; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D008956:Models, Chemical; D051381:Rats; D044967:Serum / Q000737:chemistry; D058067:Wavelet Analysis