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This laboratory experiment employs an innovative approach to introduce undergraduates to liquid chromatography-tandem mass spectrometry (LC-MS/MS) by developing a method based on multiple reaction monitoring (MRM). During this qualitative investigation, students operated a triple quadrupole mass spectrometer in the MS scan and product ion scan modes to determine precursor and product ions, respectively, for a vanillin, ethyl vanillin, and coumarin standard mixture. After identifying precursor [right arrow] product ion transitions, students conducted a 2 min liquid chromatography run in MRM mode. Students were astonished by the speed, selectivity, and sensitivity of the LC-MS/MS method compared to that of a liquid chromatograph with ultraviolet detection.

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1467-8462.2009.00551.x Byline: Paul Bloxham ([dagger]), Thomas Betts ([dagger]) Author Affiliation: ([dagger])Economic Analysis Department, Reserve Bank of Australia Article History: February 2009

Fluorescence polarization (FP) can be used as a tool by chemistry students for pinpointing vesicle thermal phase transitions. The students are first exposed to both organized media and emission polarization phenomena. They then determine the gel-to-liquid transition temperature in L-alpha-dimyristoylphosphatidylcholine (DMPC) model bilayer systems based on static FP or a lipid-related bound fluorescent marker.

This article discusses use of supra molecular chemistry in chemical research and importance of teaching its concept and applications to advanced undergraduate students.

Undergraduate chemistry students studying instrumental analysis can learn from using high-performance liquid chromatography (HPLC) to analyze hot pepper sauces for the degree of heat they generate as they go down with food. The goal of the lab experience that has been developed at Kutztown Univ., Kutztown, PA, is to help students to develop an HPLC method to separate and quantify capsaicins in 11 spicy condiments, including one oil-based sauce, before the pungency measurement was made. Students collectively found the method in a course in instrumental analysis. Compounds that give hot peppers their hot taste are known as capsaicinoids, and the two responsible 90%+ of the heat are capsaicin and dihydrocapsaicin. The analysis focused on these. Six pairs of students work on six different experiments. Each pair has one aspect of the method to develop, and they work in rotation. Natural capsaicin is very toxic and a severe irritant to skin and the upper respiratory tract. Protection is required. Grading was of necessity somewhat subjective. Instructors prepared a stock solution made from a natural capsaicin product. The Scoville method, an organoleptic method using tasters, and Scoville units, standards in the food industry, are discussed.

The LIMSport(V) can bypass the need for an expensive pH meter in a chemistry laboratory because it uses software for calibration. Instead, an inexpensive multifunction board, an operational amplifier and a pH probe can be used in conjunction with a computer while students can observe the mechanism of the analysis. Construction guidelines are included.

A procedure determining the size of solute-solvent cluster in the near-critical region in supercritical fluids using spectroscopic techniques is presented. 6-propionyl-2-(dimethylamine)naphthalene was characterized with respect to its rotational correlation time in super critical N2O using fluorescence anisotropycoupled with time-resolved fluorescence spectroscopy. The findings show a rangeof cluster sizes in supercritical N2O. Moreover, this general method can be applied to other sytems.

Steady-state and time-resolved fluorescence studies of pyrene emission in supercritical CO2 wereundertaken. Ground-state, excimer-like pyrene dimers were not formed in supercritical CO2, indicating that CO2 association around the pyrene is too weak to oppose the repulsion of the ground-state pyrene molecules. However, pyrene excimers are formed in the excited state and is absolutely diffusion controlled. Moreover, the amount of excimer decreases with increasing CO2 density.

A laboratory experiment in which the environment-sensitive nature of PRODAN fluorescence is used to determine formation constants for the complexation of beta- or gamma-CD with PRODAN has been developed. It would be suitable for students who have carried out a quantitative determination using fluorescence. They should have some familiarity with fluorescence theory and instrumentation. Cyclodextrins are cyclic oligosaccharides that have a hydrophobic cavity and a hydrophilic exterior due to the primary and secondary hydroxyl groups positioned at the rims. PRODAN is 6-propionyl-2-(N,N-dimethylamino)naphthalene.

A time efficient chromatographic method by using high-performance liquid chromatography (HPLC) equipment to separate and quantify [alpha]- and [beta]-acids in hops is described. The students learn to apply and implement with minimal HPLC equipment (isocratic, fixed wavelength detection) and a standard C-18 column.