Date of Award
Bachelor of Science
A compact laser-based spectrometer has been designed and characterized. This design of this instrument gives it the ability to collect absorbance, fluorescence, and scattering signals simultaneously. A diode laser is used as the excitation for this instrument. Several optical arrangements have been tested in order to allow for the best possible signal collection. Electronics have been designed and constructed in order to facilitate the simultaneous collection of signals. This instrument has been characterized using several dyes and scattering agents. Fluorescence limits of detection for Methylene Blue and Nile Blue A have been calculated at 2 ppb. The spectrometer has been applied to two different studies. A β-Cyclodextrin (β-CD) study has been conducted in order to determine whether recrystallization of β-CD reduces its aggregation and precipitation in water solutions near its solubility limit. Recrystallization has proven to reduce aggregation in β-CD by up to 70%. A dye-surfactant study has been performed to determine the interaction between Methylene Blue (MB. dye) and Sodium Dodecyl Sulfate (SDS, surfactant). The relationship between MB and SDS in solutions was studied at various concentrations with different solvents. The spectral characteristics of the MB-SDS interaction suggest that formation of a 1:1 or 1:>1 MB:SDS complex occurs. Hypothesis have been suggested to explain the results obtained for each application. Future modifications to the spectrometer including the addition of spectral resolution and of a photomultiplier tube detector system has been outlined.
Leach, Andrew M., "Design and application of a compact, multipurpose, laser-based spectrometer" (1996). Honors Theses. 2052.