Three operation parameters of a UV-visible spectrophotometer (scan speed, monochromator slit width, and sampling interval) were optimized utilizing a fractional factorial design. Four absorption spectra of holmium oxide were recorded in a portion of the visible region (560-610 nanometers) using different combinations of "high" and "low" levels for the parameters already mentioned. The combinations were provided by a 23-1 design. From the results it is deduced that the highest quality spectrum is furnished by the following combination: high scan speed, narrow monochromator slit width (0.2 nm.) and small sampling interval (one data point per each 0.1 nanometer). This work illustrates the usefulness of fractional factorial design as an optimization tool in the analytical chemistry laboratory.
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