The aroma volatile compounds in tomatoes are strongly linked to taste and flavor. Commercial tomato varieties, however, generally lack flavor. Tomato breeding programs have therefore started to focus on increasing the flavor-enhancing volatiles, which can be more easily altered than the sugar content. Analytical efforts that identify key flavor…

We report here a method that utilizes the vapor pressure of HCl(g) above a concentrated HCl(aq) solution as an extremely simple and safe method to produce small amounts of HCl vapor in an IR gas cell. This vapor pressure approach can also be used to produce DCl(g) by introducing a few drops of concentrated DCl(aq) into the gas cell.

Adsorption of methylene blue and malachite green was carried out using "Luffa cylindrica" sponges as adsorbing material. We provide a very illustrative exercise about the use of common natural materials requiring little preparation to solve environmental tasks in a routine laboratory situation such as using dyes. In addition, the…

An experiment involving a moisture-sensitive synthesis and spectroscopic characterization suitable for the advanced inorganic laboratory course is presented. The acid-base complex ammonia borane (AB) is synthesized from the heterogeneous reaction between sodium borohydride and finely ground ammonium sulfate in tetrahydrofuran solvent. AB is…

Reported herein is a multidisciplinary laboratory experiment for advanced undergraduate students that includes elements of material synthesis, in the synthesis of cyclodextrin-containing metal-organic frameworks (CD-MOFs), and environmental chemistry, in the use of these MOFs for pollutant removal. This multiday laboratory experiment starts with…

The redox reaction between dioxovanadium(V) and oxalate is proposed as a suitable system to analyze the kinetics of a twostep reaction mechanism using UV-vis spectroscopy. First, the spectra of dioxovanadium(V) and its reduced counterpart oxovanadium(IV) are compared and explained using the crystal field theory. The change in absorbance can be…

The synthesis of 4-amino-3-nitrobenzoic acid methyl ester is a simple Fischer esterification reaction designed as an experiment for use in an introductory organic chemistry course. The compound was synthesized as a one-pot reaction within 30 min to 16 h, with 1 h producing a workable yield. The bright-yellow solid was purified using liquid--liquid…

Keto-enol tautomerism is a fundamental concept that examines the migration of a proton between two constitutional isomers, the keto and enol tautomer. Many experiments have been proposed to understand the concept behind Meyer's Rule, which states that the keto tautomer is favored as the solvent polarity increases. However, all the experiments have…

This paper reports the development and application of a low-cost multifunctional webcam spectrophotometer for the conduct of molecular absorption and fluorometric measurements. The equipment, which costs approximately US$20 to be fabricated, consists of a webcam, a diffraction grating, and a slit, all positioned inside an MDF box. Spectral…

Here we present a new undergraduate laboratory that will introduce the concepts of time-resolved spectroscopy and provide insight into the natural time scales on which chemical dynamics occur through direct measurement. A quantitative treatment of the acquired data will provide a deeper understanding of the role of quantum mechanics and various…

In 1972 Christian B. Anfinsen received the Nobel Prize in Chemistry for "…his work on ribonuclease, especially concerning the connection between the amino acid sequence and the biologically active conformation." The understanding of this principle is crucial for physical biochemistry students, since protein folding studies, bio-computing…

An advanced undergraduate organic chemistry laboratory experiment involving a rhodium-catalyzed intermolecular hydrocarbon C-H oxidation reaction is described. In the initial phase of this lab, students conduct a C-H amination reaction of ethylbenzene and isolate a benzylic amine product. In the second part of the lab, competition experiments are…

The Beer-Lambert law is a fundamental relationship in chemistry that helps connect macroscopic experimental observations (i.e., the amount of light exiting a solution sample) to a symbolic model composed of system-level parameters (e.g., concentration values). Despite the wide use of the Beer-Lambert law in the undergraduate chemistry curriculum…

This experiment introduces undergraduate organic chemistry students to analysis and interpretation of Fourier transform infrared (FTIR) spectra through characterization of postconsumer plastics. Students use FTIR spectra to identify and differentiate the common recyclable polymer resins #1-6: polyethylene terephthalate (PETE), polyethylene (HDPE…

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…