Quantitative Determination of Chromium(VI) Using Sol-Gel Encapsulated Redox Chemistry
Project Description
Determining chromium, especially in environmental and biological samples, is important to many scientists. However, most methods of measurement for chromium only determine total chromium in the sample, not necessarily the forms that chromium can exist. As it is known that Cr3+ (a trace nutrient) and Cr6+ (toxic and carcinogenic) exists naturally, it is highly useful to have an approach that allows the determination of each species of Cr.
Efforts in our laboratory are being made to develop a method for the spectrophotometric determination of Cr6+. The main goals are to provide a selective, sensitive, time-effective and simple approach for this purpose. The work will be based on the encapsulation of leuco-crystal violet(colorless) in a sol-gel matrix. A series of redox reactions triggered by the presence of Cr6+ ultimately creates crystal violet (purple-colored) which can be measured in a simple spectrophotometer. Ultimately, we hope to create a quantitative, sub-ppb technique for this important determination.
Last summer (2008), the research focus was to consistently synthesize optically clear sol-gel materials for use in the encapsulating leuco-crystal violet. The efforts in the coming summer are aimed at more fully characterizing the encapsulated system for the measurement of Cr+6. The characterizations will include studies of the conditions of the analytical reactions, a more complete understanding of the spectroscopic behavior of cystal violet in the sol-gel matrix, and efforts to control and assess the quantitative performance of the reaction system.
Efforts in our laboratory are being made to develop a method for the spectrophotometric determination of Cr6+. The main goals are to provide a selective, sensitive, time-effective and simple approach for this purpose. The work will be based on the encapsulation of leuco-crystal violet(colorless) in a sol-gel matrix. A series of redox reactions triggered by the presence of Cr6+ ultimately creates crystal violet (purple-colored) which can be measured in a simple spectrophotometer. Ultimately, we hope to create a quantitative, sub-ppb technique for this important determination.
Last summer (2008), the research focus was to consistently synthesize optically clear sol-gel materials for use in the encapsulating leuco-crystal violet. The efforts in the coming summer are aimed at more fully characterizing the encapsulated system for the measurement of Cr+6. The characterizations will include studies of the conditions of the analytical reactions, a more complete understanding of the spectroscopic behavior of cystal violet in the sol-gel matrix, and efforts to control and assess the quantitative performance of the reaction system.
Background Needed
Prefer a student who has had quantitative analysis class, though completion of general chemistry is a must.