|Title||Analysis of complex samples using a portable multi-wavelength light emitting diode (LED) fluorescence spectrometer|
|Publication Type||Conference Paper|
|Year of Publication||2008|
|Authors||Bai B, Anderson D.M., Rayson G.D.|
|Conference Name||Federation of Analytical Chemistry and Spectroscopy Societies|
|Conference Location||Reno, Nevada|
|ARIS Log Number||245901|
Spectroscopic analysis of chemically complex samples often requires an increase n the dimensionality of the measured response surface. This often involves the measurement of emitted light intensities as functions of both wavelengths of excitation and emission resulting in the generation of an excitation-emission matrix (EEM) for each sample. Unfortunately, the complexity of instrumentation for selective illumination of samples with narrow wavelength band-widths of excitation radiation typically limits the application of such measurements from the analysis of in-field samples. This has recently been addressed by the use of a collection of light emitting diodes (LEDs) as excitation sources with varied wavelengths for the generation of EEMs. Although these sources emit relatively broad wavelength bands, analysis of the resulting multi-dimensi0ona spectral signatures using multivariate techniques (e.g., PCA and PARAFAC) enables the direct analysis of complex samples. Application of this technique to agriculturally important samples will be described and the implication of these results for in-field determinations will be discussed.