Characterization of Titanium Tiles as Novel Platforms for Micro-Flame Ionization Detection in Miniature Gas Chromatography

A titanium miniature gas chromatography device with an on-board micro-flame ionization detector (Ti µGC-FID) is presented. The design is based on a counter-current method that establishes a stable flame (~240 µm diameter) inside a 1.44 mm circular cavity within the Ti tile. The width of this cavity is found to have a significant impact on flame stability and detector performance. Through polarizing the conductive Ti tile body and situating a collector adjacent to the cavity, useful µFID response is obtained from the flame. The 7.5 cm × 15 cm rectangular monolithic Ti device contains a serpentine column layout (5 m long × 100 μm wide) coated with OV-101 stationary phase that is directly integrated with the on-board μFID. The column produces reasonable analyte peak symmetry and separation performance with a plate height of 1.5 mm for dodecane. Under optimized conditions, the Ti μGC-FID device yields a detection limit of 9 × 10 −12 gC s −1 , a linear response over 3 orders of magnitude, a sensitivity of 60 mC gC −1 , and a signal reproducibility within 5% RSD ( n = 10). Some samples are analyzed using the Ti µGC-FID device and results indicate that this approach can potentially provide a useful alternative means of achieving sensitive and stable μFID performance within a robust, integrated miniaturized GC platform. Graphical Abstract