Utilizing Linear Solvation Free Energy Relationship methodology, a novel pyridinium bromide surface confined ionic liquid (SCIL) stationary phase was characterized under normal phase High Performance Liquid Chromatographic conditions. A limited set of neutral aromatic probe solutes were utilized to rapidly assess the utility of the LSER model, using mobile phases of hexane modified with 2-propanol. The excellent correlation of the global fit across the mobile phase composition range used in this study for the experimental and calculated retention values (R 2 = 0.994) indicates that the LSER model is an appropriate model of characterizing this polar bonded phase under normal phase conditions. For a limited subset of compounds, retention on the pyridinium bromide SCIL stationary phase is more highly correlated with that obtained on a cyano column than on a diol column under NP conditions.

We have designed a laboratory experiment to illustrate the use of spectroelectrochemical techniques for determination of aqueous iron. The experiment described in this article is applicable to an undergraduate laboratory course in analytical chemistry. Students are asked to fabricate spectroelectrochemical sensors, make electrochemical and optical measurements, and relate the analytical signals to aqueous iron concentrations by constructing a calibration curve. Three optional experiments are also offered, which can be performed during the 2-hour slide-soaking period at the discretion of the instructor.