Screening and Sequential Experimentation: Simulations and Flame Atomic Absorption Spectrometry Experiments
| Autor: | Richard J. Stolzberg |
|---|---|
| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Journal of Chemical Education. 74:216 |
| ISSN: | 1938-1328 0021-9584 |
| DOI: | 10.1021/ed074p216 |
| Popis: | Students are introduced to screening and sequential experimentation using simulations and experimentation. The work begins with spreadsheet simulations and practice with the experimental design software. Students learn how to use the graphical output, normal quantile plots, to recognize the specific factors that affect the result of an experiment. In the laboratory, students make a preliminary investigation of the effect of six variables (flame observation height, flame stoichiometry, acetic acid, lamp current, wavelength, and slit width) on the atomic absorption signal for silver. This requires only sixteen experiments. Two or three active variables and an interaction of two variables are typically observed. Following this 26-2 fractional factorial design experiment, students investigate the effect of two active variables in more detail. This typically requires 16 to 25 experiments. The complexity of the system becomes apparent when flame observation height and percentage of acetic acid are studied. Most, but not all, of the observations are consistent with descriptive material that would be found in a typical instrumental methods text. |
| Databáze: | OpenAIRE |
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