Students in the Webb group perform research towards improving chemical analysis. Such analysis is the identification of what elements and compounds are in a substance, and the measurement of how much of these elements and compounds are present.
Chemical analysis is vital to many fields. Forensic chemist measure trace evidence to solve crimes. Environmental chemists measure both pollutants and natural substances to understand their roles in the natural world. Synthetic organic chemists makes sure they have made their target compound and determine how efficiently they have made it. Biologists and biochemists identify and measure metabolites, proteins, and DNA. Chemical analysis is a part of quality control in the manufacture of a wide range of consumer products. A broad variety of industries use chemical analysis to ensure that they are complying with environmental regulations. Chemical analysis is similarly used to ensure food safety.
Analytical chemists are scientists who develop and improve methods for chemical analysis. In the Webb Group, we focus on analytical instruments. These instruments are tools or devices used in chemical analysis. They are often shown in forensic dramas as the "machines" with which evidence is analyzed. Current projects in the Webb group focus on two instruments: solution-cathode glow discharge and cromoscope. The patents for both instruments and articles about them can be found in the publications section of this web site.
Solution-cathode glow discharge is a plasma useful for elemental analysis of aqueous samples. The fundamental principle behind it is similar to that of a Bunsen burner flame test. A sample is introduced into the plasma, and the plasma breaks it down into its atoms and causes those atoms to emit light. A Bunsen burner flame has enough energy to break down and excite only a handful of elements, and the light from those elements is only observable if the elements have a high concentration in the sample. Solution-cathode glow discharge can be used to measure much lower concentrations of a wider variety of elements. Performance is in many ways comparable to much larger, more expensive instruments.
The cromoscope is a blend of a monochromator and a microscope. It is capable of acquiring images of microscopic samples where the light is just a narrow wavelength band. While the human eye interprets the color of light based on the relative amounts of just three responses (red, green, and blue), the cromoscope can combine hundreds of measurements at different wavelengths to make a spectrum. Because of this, the cromoscope can distinguish between colors that appear the same to the human eye. We are currently exploiting this ability to develop a method for forensics that will let us distinguish between different brands of blue pen ink.
All Webb Group alumni have found jobs in chemistry or have been admitted to graduate school.
If you are interested in joining the Webb Group, send Dr. Webb an . We have projects for both undergraduate and graduate students. We do not have any openings for postdoctoral researchers.