Resumen de An Advanced Undergraduate Chemistry Laboratory Experiment Exploring NIR Spectroscopy and Chemometrics.
Randall Wanke, Jennifer Stauffer
An advanced undergraduate chemistry experiment for an instrumental analysis course or analytical chemistry course is described to familiarize students both with NIR spectroscopy and chemometrics. Students measure NIR spectra of toluene, heptane, and isooctane solutions in the 6400�5150 cm-1 region of the electromagnetic spectrum and develop an accurate and precise (±0.6% absolute) chemometrics calibration model to predict component concentrations. Experimental exercises are described to examine the calibration model and discern its limitations. Selective substitution experiments pinpoint the CH2/CH3 ratio and the aromatic ring as a key factors in the calibration model. Further exercises show how alterations of sample and analysis conditions adversely effect quantitation using the tailor-made chemometrics calibration model.
