High performance liquid chromatography is useful in determining not only what components are in an unknown sample, but, if done properly, also the concentrations of the components. After given an unknown mountain dew-type soda and asked to determine the concentration of the caffeine within it, using HPLC seemed a logical choice. While one typical HPLC chromatogram is not useful in determining concentration, by employing standard addition of a known concentration, using the range of data and creating a graph, the concentration can be calculated. By adding a changing amount of standard to a constant amount of unknown, the changing area can be correlated to concentration. However, before such tests could be conducted, it was necessary to determine what mobile phase results in the best separation between the two major components of the soda – caffeine and benzoate. By testing solutions with changing ratios of water and methanol with a standard solution of mixed 0.1018 mg/mL of caffeine and 0.3014 mg/mL of benzoate, it was determined that the mobile phase of 50% water/50% methanol produced the best separation. Once that was decided, it was necessary to test the above mentioned concentrations of caffeine and benzoate, but separately so that the individual peaks could be identified on the chromatogram. Finally, the unknown could be tested through standard addition, resulting in a concentration of caffeine, with the 95% confidence interval, of 0.07997 ± 7.94% mg/mL.

In order to determine the concentration of lead in a solution, the technique of flame atomic absorption was employed. An AA-6300 Shimadzu Flame Atomic Absorption Spectrophotometer was used, as well as an ACS-6100 auto-sampler. The flame was fed with acetylene and air, and the chosen emission line was 283.3 nm. By creating a calibration curve from standard solutions of Milli Q water and a stock solution of 20 ppm of lead, the lead concentration of eight unknown samples was calculated. Six of the eight samples (all four water samples, Licorice A/F, and Kava Kava) were below the limit of detection. The other two samples produced calculable concentrations. American Skullcap had a concentration of 1.683 ppm and Clove Buds had a concentration of 1.600 ppm.

Using a differential scanning calorimetry, a multitude of things can be calculated concerning the structure and purity of poly(ethylene terephthalate). During the course of the experiment, the following values were determined. The entropy of fusion for PET was found to be -0.08 J/g*K; the glass temperature was found to be 75.73 °C; the weight percent of DEG in the PET was found to be 7.1%; the percent of crystalline in PET was found to be 21.86%; the percent of crystalline in quenched PET was found to be 4.21%. The importance of this is that the structure of PET changes when heated and rapidly cooled. The rapidly cooled PET forms much less crystals than the original, produced PET, which goes through a much slower cooling process in production.

Next to the wheel, the discovery of fire has influenced the development of mankind the most of any scientific discovery. Since then, man has not been able to find enough uses for fire – from heating to killing to entertainment, the fascination runs deep. One of the older uses of fire is in fireworks. In the eleven hundreds, the Chinese used fireworks to scare evil spirits. Nowadays, fireworks are used in celebrations or entertainment shows. Nothing draws people together like dancing lights and the risk of fire.