Design Team Members: Claire Zhao and Mitch Laslau
Supervisor: Prof. Arsen Hajian
Background
Absorption spectroscopy measures the intensity of light absorbed by an object as a function of the light’s wavelength. The resulting plots are called absorption spectra and can indicate the presence or quantity of a specific substance in the sample. A variety of spectroscopic techniques are available, depending on the wavelength range being studied and the characteristics of substances being measured.
This research project will investigate the potential of spectroscopy in quantifying concentration of materials found in blood. The tests will be performed on blood proxies, specifically milk and gasoline. If successful, spectroscopy as an analysis tool will be compared to current techniques used to analyze blood.
Currently, spectroscopy is already applied to many biomedical analyses. For instance, of the six most common types of serum analyzes performed in a clinical laboratory, the Institute for Biodiagnostics of the Natural Research Council of Canada has shown that all of these can be measured through a single mid-infrared (IR) serum absorption spectrum. The benefits of spectroscopic techniques are that it removes the need for reagents, minimizes sample volume, and provides analytical results not available from traditional tests.
Project description
A number of certificates are needed to perform spectroscopy on blood. In order to avoid the long waiting period, two other substances will be used as proxies to real blood, namely milk and gasoline. Milk contains many of the same vitamins and proteins found in blood. Similarly, gasoline contains hydrocarbon structures that are similar to lipids in blood. The analyte that will be measured in blood is Vitamin D. The analytes that will be measured in gasoline include isoocatane, n-benzene, and toluene.
A theoretical model will be developed to predict the parameters of the spectroscopic analysis. These parameters are needed to adequately capture the spectra. A number of suitable samples will be created for the experiment. After performing the actual experiment, an in-depth analysis of the data will be carried out in order to evaluate the accuracy of the procedure.
A basic spectrometer will also be designed and constructed. Due to the different wavelength regions used in the spectroscopy of Vitamin D and the spectroscopy of gasoline, a spectrometer cannot be designed that will accommodate both. Due to the ready availability of spectrometer parts in the NIR region, the spectrometer will be designed specifically for the spectroscopy of gasoline. A modified experimental procedure accommodating the different spectrometer specifications will be conducted.
Design methodology
The research project will be completed in four stages: background research, modeling, experimentation, and analysis.
The first stage will consist of general background reading and a literature review of the field of spectroscopy. Research will be done on the basic physics behind absorption spectroscopy, as well as spectroscopic hardware. This will provide the necessary background to prepare models, design proper experimental procedures for the actual spectroscopic analysis, and analyze experimental results. While a number of papers address the quantitative measurement of various substances in milk through spectroscopy, the quantification of Vitamin D in milk has not been thoroughly explored. This research project will aim to address this gap. With regard to gasoline, however, several studies have already been carried out on the analysis of octane numbers through IR spectroscopy. Comparison with these materials will help evaluate the methods used in this project as well as provide references for the spectrometer design.
In the second stage of the project, an experimental procedure will be the developed to be carried out at the facilities of a local spectroscopic manufacturer. This stage will involve mathematical modelling, determination of spectroscopic parameters, sample preparation, and development of experimental plan. A full experimental plan detailing the procedure, sample preparation, calibration and a preliminary method for the data analysis will be outlined.
Once preparation is complete, two weeks of time will be arranged at the spectroscopic lab facilities to access one of their state-of-art spectrometers as well as obtain training from one of their employees. During this time, the experiment will be performed and data will be collected.
The data will be analyzed to compare the results of the experiment to that predicted by our model. Using off the shelf components, a basic spectrometer will be constructed in the optics lab at uWaterloo. Using a modified experimental plan adapted to this particular instrument, the spectroscopy analysis will be repeated. Similarities and differences between the actual and expected results for both spectrometers will be summarized in a final report. Analysis will likely incorporate principles from statistics, pattern recognition, optics, and image enhancement.