This manual is the culmination of the efforts of many individuals. While some of the experiments are "classics", and appear in various forms in many Quantitative Analysis textbooks and laboratory manuals, much effort was expended to ensure that the experiments work well here at UC Davis and thus each experiment has been extensively tailored for our laboratory program. We view this manual as one of continual modification, and often improvements arise from comments and criticisms.
Introductory DetailsExperiments have been set up for students working in small groups. Be sure to have a work plan that makes efficient use of your time. Lengthy sample preparation procedures should be started early in the six hours assigned to a given experiment. Chem 115 Lab Report Evaluation FormThis is the lab evaluation form. Statistical Treatment of DataMany times during the course of the Chemistry 115 laboratory you will be asked to report an average, relative deviation, and a standard deviation. You may also have to analyze multiple trials to decide whether or not a certain piece of data should be discarded. This section describes these procedures. Lab 1: Cyclic VoltammetryCyclic voltammetry (CV) is a technique used to study electrochemical reaction mechanisms that give rise to electroanalytical current signals. The method involves linearly varying an electrode potential between two limits at a specific rate while monitoring the current that develops in an electrochemical cell under conditions where voltage is in excess of that predicted by the Nernst equation.¹ Lab 2: High Performance Liquid ChromatographyHigh performance liquid chromatography (HPLC) makes use of a high pressure pump to deliver a mobile phase solvent at a uniform rate at pressures that are typically from 500 to 5000 psi. The most obvious advantage of HPLC over gravity liquid chromatography is that samples can be separated much more quickly. Lab 3: Fourier Transform Infrared Spectroscopy (FTIR)The FTIR / Vibrational spectroscopy exercise follows the format of a detective story involving solving a series of problems rather than the normal lab format. The experiment is an adaptation of "Pollution Police" by Profs. Jodye Selco and Janet Beery at the University of Redlands, which was presented at the Division of Chemical Education Regional ACS meeting in Ontario, CA 1999. Lab 4: Molecular FluorescenceWhen a molecule absorbs a photon in the ultraviolet or visible (UV VIS) region (180 - 780 nm), an electronic transition occurs within the molecule. This transition involves moving an electron from the singlet ground state to a singlet excited state. Lab 5: Gas Chromatography/Mass Spectrometry (GC/MS)This lab involves the analysis of different unknown mixtures by high resolution capillary gas chromatography (GC) with an ion trap detector (ITD). The ITD is a variation of a quadrupole mass spectrometer and is designed to function specifically as a GC detector. Due to the design variances of the ITD compared to a true quadrupole mass spectrometer, the ITD mass spectrum of an organic compound may not be identical (but should be very similar) to its classical electron impact (EI) mass spectrum. Lab 6: Capillary ElectrophoresisElectrophoresis is a class of separation techniques in which we separate analytes by their ability to move through a conductive medium—usually an aqueous buffer—in response to an applied electric field. In the absence of other effects, cations migrate toward the electric field’s negatively charged cathode. Lab 7: Electrospray Mass SpectrometryIn this experiment you will learn the mechanics of electrospray mass spectrometry and use this technique to study the effect of different solvents on the three-dimensional structure of proteins.