This work demonstrates the first study on interfacing of microfluidic chip-based chromatography to flame atomic
absorption spectrometry (FAAS) for a simple and fast separation or preconcentration and subsequent determination
of species. The developed low-cost polydimethylsiloxane microchip includes 12 microcolumns of
conventional C18 (5 μm) chromatographic particles, making the parallel chromatographic separation/
preconcentration and the direct introduction of the effluent into the spectrometer possible. In order to test
this hyphenated microchip–FAAS system, the Cr(VI) was selected to be determined. The adsorbed Cr(VI) was
eluted with methanol, and the 30 μL effluents were collected into plastic vessels inserted into the ends of the
microcolumns. Then, the effluents were analyzed by FAA spectrometer using micro-injection of the effluents
as discrete samples. The separation/preconcentration and FAAS determination of 12 samples needed less than
5 min due to the multiplex feature of the proposed system. The overall capacity of the microcolumn (C18,
5 μm beads, 20 mm × 1 mm × 0.1 mm) was calculated to be 0.45 μg/mm for Cr(VI). Loading only 80 μL samples
onto the microchip and nebulizing the methanolic effluent of 30 μL into the FAA spectrometer, 0.0031 μg/mL
limit of detection was obtained.