Chem. Educator 2002, 7, 149154 149 MillerUrey Revisited: When Lightning Strikes the Earth William Paneral,  Brent Leslie,  Derek Lovingood,  Robert Stapleton,  Mike Anderson,  Anna McRae,  Leri Atwater,  Thomas Manning, *, and Dennis Phillips  Department of Chemistry, Valdosta State University, Valdosta, GA 31698, tmanning@valdosta.edu, and Chemistry Department, University of Georgia, Athens, Georgia Received February 1, 2002. Accepted March 19, 2002 Abstract: A discharge is arced to different solutions containing the simple molecular species water, methanol, and ammonia. We show that the impact of the discharge at the dischargesolution interface produces a range of organic molecules, including amino acids and polymers containing carboxylate, amine, imine, and cyano groups. The classic MillerUrey experiment, of which there are hundreds of variations, changing parameters such as gas composition, pressures, and voltage have been tested, involves the production of simple amino acids and other species in the gas phase in an arc discharge. This works emphasis is the production of various chemical species at a dischargeliquid interface. The analysis of the product is conducted by IR, UVVIS, LCMS and MALDI MS. As a laboratory exercise or a demonstration, this simple derivation of the MillerUrey experiment can be used in a variety of teaching settings, from high school through advanced undergraduate research classes to demonstrate the basic hypothesis of how life on Earth may have started. Introduction In the classic MillerUrey experiment, an arc discharge is used to convert simple gas-phase molecules, such as water, methane and ammonia, into simple amino acids [1, 2]. It was originally argued that under primordial conditions the arc discharge replicated lightning and provided the molecular building blocks for evolution. Since that time, research has extended in other directions such as the role of ultraviolet light in the photochemical production of molecular species [3], amino acids found in meteorites and comets [46], as well as a large number of investigations into various aspects of molecular evolution [720]. In this experiment we tried a similar but fundamentally different approach to converting simple molecular species to larger ones. We arced this discharge directly to a liquid containing simple molecular species (water, ammonia, methanol) in different ratios, atmospheres, and pHs. We justify the use of methanol because methane, which was believed to be in the earliest atmosphere, will produce methanol in the presence of water. The theory presented in this research is that a solution is about 1,000 times denser than a gas and consequently contains a much higher concentration of chemical species. Not only will more species be present to react during the discharge they will be in a more static environment (compared to the gas phase) for additional reactions after the discharge has ceased. In searching the molecular evolution literature, there exists a large body of data stretching decades in which various gas-phase molecular species (H 2 O, NH 3 , CH 4 , O 2 , H 2 , etc.) at various ratios and under varying conditions (voltage, current density, total pressure, etc.) exist [120]; however no experimental data exist that we could find where a high voltage discharge strikes a solid or liquid and the chemical products were analyzed for the basic building blocks of life. * Address correspondence to this author.  Valdosta State University  University of Georgia Typically, MillerUrey is introduced in biology classes, but this experiment was conducted as an exploratory laboratory in physical chemistry. In addition to the experimental work described below, students were asked to calculate heats of reaction for the various products formed (glycine, urea, etc.) using both bond energies obtained from various texts and heats of formation obtained from the NIST webpage (http://webbook.nist.gov/chemistry/). As with any evolution discussion, this was presented as a scientific hypthothesis and not fact. We discussed that while this experiment showed how some of the building blocks of life could be formed not only on earth but also on other planets in our solar system or others, it did not show how inert chemicals combine to form a living organism. In order to balance all concerns on this delicate issue but also present an intriguing experiment, it was important to clearly discuss what science had and had not been able to replicate in the laboratory. Experimental The experimental apparatus (see figure 1) was sealed at ambient pressure and temperature and with different atmospheres (air, N 2 , Ar). A Tesla coil that discharged at 0.5 MHz and 50 kV was placed approximately 1 cm above the liquid (50 mL total volume) and allowed to run for time durations of 3 to 24 hours (see Figure 1). We should note that running the Tesla coils for extended periods of time shortened their life times. Infrared measurements of dried samples were made using a Mattson FTIR spectrometer and 3M IR cards. A PerkinElmer Lambda II UVVIS spectrometer was used for solution absorbance measurements. The resulting solutions had to be diluted between 5 and 50 fold to bring solution absorbance measurements onscale. A pH measurement was made of aqueous-phase mixtures (i.e. water and NH 3 ) and then methanol was added and the pH adjusted by a dilution calculation. Dilute solutions (0.1 M or less) of NaOH and HCl were used to adjust pH. The first series of experiments involved mixtures of water, ammonia (1.0 M NH 3 starting concentration), and ' 2002 Springer-Verlag New York, Inc., S1430-4171(02)03563-1, Published on Web 05/24/2002, 10.1007/s00897020563a, 730149tm.pdf