By Mitchell ZimmerMicrocapillaries and bio-oil lead to Analytical Chemistry prize for Booker
In her career as a Chemistry Ph.D. student, Christina Booker has been simultaneously working on two projects that couldn’t be more different in scale. One is developing a technique using micro capillaries as tiny test tubes that are no wider than a human hair to concentrate dilute protein solutions to be analysed by spectrometry. The other is separating the myriad of components from bio-oil and determining which fractions are the active ingredients that have a pesticidal function. This combined work has won Booker the Analytical Chemistry Division Graduate Student Award in Honour of Walter E. Harris bestowed by the Chemical Institute of Canada.
The microcapillaries Booker uses are only 50 micrometers thick and contain a different solution at each end. One end contains an acidic solution and the other a basic solution. Where the two solutions meet inside the tube is called the pH junction. Now suppose that a dilute protein sample has been introduced into either of the two solutions before loading. If an electric current is applied through the tube, anything carrying a charge in the solution will move toward the electrode of the opposite charge. As Booker explains, “permanently charged ions and buffers can proceed through the pH junction because their charge remains constant whether they are in an acid or a base. Proteins have an isoelectric point so they can be captured. We can see this very sharp band go past the detector and we can identify it using mass spectrometry… You can also perform a subsequent separation on the enriched, purified protein band.” The entire capillary holds only 1 microliter (that is one millionth of a liter) of solution. Even though the technique is under development, it has the potential to be a great help to analytical chemistry. There are proteins which occur in such low concentrations that chemists can only suspect that they exist, as Booker says, “so here we can concentrate them by 100 to 1,000 fold and then you are able to detect it.”
The production and analysis of bio-oil is the other project Booker works on. This effort is a collaboration between the Faculties of Science and Engineering as well as Agriculture and Agri-Food Canada. The process takes waste products such as coffee grounds or tobacco leaves and heats them up in the absence of oxygen. The production of fuel from the resulting crude oil may be environmentally friendly but not economically feasible so researchers have been looking for another use. As Booker said in her research report “We have discovered that bio-oil, a complex mixture of thousands of chemical, has pesticide properties.” When oil was derived from tobacco leaves, the research team fully expected that the nicotine extracted from the crude product would be effective against a common pest, the Colorado Potato Beetle. What proved interesting was that the nicotine-free portion of the bio-oil still possessed pesticide activity towards the beetle as well as a variety of microorganisms. Booker is now investigating methods to find the active chemicals. Liquid chromatography has yielded multiple active mixtures and further separations have to be performed to isolate the individual chemicals. “It is highly likely that many, low abundance chemicals are working together to generate the observed pesticide activity,” says Booker.
Booker will receive a cash award and framed certificate as well as a presentation at the next annual CSC meeting.
