title: Oligosaccharide identification and mixture quantification using Raman spectroscopy and chemometric analysis.
abstract: This work demonstrates the feasibility of using Raman spectroscopy for the analysis of small quantities of chemically similar oligosaccharides and their mixtures. Raman spectra were obtained from 10-microL aliquots of 1 mM solutions of maltotetraose and/or stachyose after deposition onto an electrochemically roughened silver substrate (and the resulting spectral features are attributed to a combination of normal and surface-enhanced Raman scattering). These compounds were selected because they are representative of glycans derived from post-translationally modified proteins which, like these compounds, often consist of isomers of equal mass and similar shape. Replicate spectral measurements were recorded and processed using a partial-least-squares (PLS) classification and quantification algorithms with a leave-one-batch-out (LOBO) training and testing procedure. Spectra derived from solutions of individual sugars were identified with 100% accuracy, and mixtures of the two sugars were quantified with an average error of 2.7% in the relative maltotetraose/stachyose composition for mixtures with a total oligosaccharide concentration of 1 mM.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Melissa F
authors.initials: MF
authors.lastname: Mrozek
authors.forename: Dongmao
authors.initials: D
authors.lastname: Zhang
authors.forename: Dor
authors.initials: D
authors.lastname: Ben-Amotz
mesh_terms: D000465:Algorithms; D007536:Isomerism; D008320:Maltose / Q000031:analogs & derivatives / Q000737:chemistry; D009844:Oligosaccharides / Q000032:analysis* / Q000737:chemistry / Q000302:isolation & purification; D011134:Polysaccharides / Q000737:chemistry; D011506:Proteins / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods
chemical_list: D009844:Oligosaccharides; D011134:Polysaccharides; D011506:Proteins; C005695:stachyose; D008320:Maltose; C009819:maltotetraose