This experiment provides students with opportunities to learn techniques in analytical electrochemistry and environmental chemistry, while engaging in real-world experiments with interesting analytes. The sample extraction method enables the analysis without the risk of inhaling cigarette smoke, but only provides an upper bound for the amount of metal exposure for smokers. In terms of learning outcomes, this experiment covers concepts and techniques in electrochemistry, voltammetry, ultrasonic extraction, and the standard addition method. At PSU many of our Instrumental Analysis experiments apply the method of standard additions and an error analysis for this method is provided in the Appendix.
When the analytes are detected in the sample solution (some brands of cigarettes, especially the large name brands, did not contain measureable lead or cadmium) 3 to 4 spikes are recommended. If not, at least one standard addition is recommended to establish the analytical detection limit.
The cost of the PDV6000plus used in this experiment was not inconsequential but it should be possible to replicate the experiment using any suitable potentiostat and electrodes, if they are already available. The PDV6000plus offered a simple "single box" solution with a complete electrochemical cell, computer interfaced potentiostat, software, and sets of solutions (plating, standards, electrolytes, cleaning). The device is also field-portable, allowing the instructor to adapt this experiment to field application or science outreach efforts. This feature is obviously not as readily available for other elemental analysis methods like ICP-AES or AAS.