Development of a digital micromirror spectrometer for analytical atomic spectrometry.

A digital micromirror device (DMD) has been incorporated into a novel spectrometer for use in analytical atomic spectrometry. The device can be taken from a commercial computer projector. A protective glass window covering the DMD chip limits the viewable wavelengths to the visible range. The DMD is used to project an image of the light source onto the exit plane of a flat-field spectrograph. A single photomultiplier tube is used for detection. The high switching rate of the micromirrors (15 μs) enables rapid full-spectrum capture, wavelength-modulation, source-modulation, fast narrow-wavelength window scans, and rapid-wavelength "jumping." Calcium, sodium, and potassium have been determined in several standard reference materials (tomato leaves, bovine liver, rice flour, total diet) by flame atomic absorption and emission spectrometry. Absorption sensitivities for each element are near the 0.02 μg/mL level, and detection limits for both absorption and emission are near the 0.01 μg/mL level. Elemental recoveries were within 10% of certified values for most reference materials.