Distinguishing Monosaccharide Stereo- and Structural Isomers with TOF-SIMS and Multivariate Statistical Analysis

• Published in: Analytical chemistry (Washington) Vol. 78; no. 18; pp. 6497 - 6503
• Main Authors: Berman, Elena S. F., Kulp, Kristen S., Knize, Mark G., Wu, Ligang, Nelson, Erik J., Nelson, David O., Wu, Kuang Jen
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.09.2006
• Subjects: Analytical chemistry; Carbohydrates; Chemistry; Exact sciences and technology; Mass spectrometry; Mass Spectrometry - methods; Monosaccharides - chemistry; Multivariate analysis; Principal Component Analysis; Reproducibility of Results; Spectrometric and optical methods; Stereoisomerism; Stereoisomer; Statistical analysis; Fragmentation pattern; Secondary ion mass spectrometry; Selectivity; Multivariate analysis; Fragmentation; Isomer; Biological compound; Time of flight method; Reproducibility; Sugar; Principal component analysis
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac060865g

Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is utilized to examine the mass spectra and fragmentation patterns of seven isomeric monosaccharides. Multivariate statistical analysis techniques, including principal component analysis (PCA), allow discrimination of the extremely similar mass spectra of stereoisomers. Furthermore, PCA identifies those fragment peaks that vary significantly between spectra. Heavy isotope studies confirm that these peaks are indeed sugar fragments, allow identification of the fragments, and provide clues to the fragmentation pathways. Excellent reproducibility is shown by multiple experiments performed over time and on separate samples. This study demonstrates the combined selectivity and discrimination power of TOF-SIMS and PCA and suggests new applications of the technique including differentiation of subtle chemical changes in biological samples that may provide insights into cellular processes, disease progress, and disease diagnosis.