CHEM 3440 Midterm: CHEM 3440 Midterm Fall 2005
Document Summary
No additional aids will be necessary as a series of data and equation sheets are included as part of the examination paper. (8 points) polycyclic aromatic hydrocarbons (pah) is a class of organic compounds that have important toxicological effects. Their detection and measurement in environmental conditions is a vital health concern. A method was developed to measure these compounds from waste water samples. The first step was the extraction of the pah from the water into methylene chloride. The efficiency of this step was tested by injecting known amounts of various pah substances into an aqueous sample and then quantifying the extracted amount. The following table reports the results of several trials for four different compounds. Note the different added amounts in each case. The mean recovered values and the standard deviation of those means are shown at the bottom. On average, however, the input signal current was 1. 5 a.
