(618f) A NOVEL Reactive Chip for Analysis of Carbonyl Compounds in Exhaled Breath

We report a fabricated reactive chip with thousands of micropillars in a microfluidic channel that have been engineered to selectively preconcentrate trace volatile carbonyl compounds (ketones and aldehydes) in exhaled breath. Certain carbonyl compounds have been identified as biomarkers of lung diseases including lung cancer, Tuberculosis, and cystic fibrosis. The chips are fabricated using deep reactive ion etching (DRIE) of silicon. The micropillar surface is functionalized with a reactive quaternary ammonium aminooxy salt or a reactive neutral aminooxy compound for trapping trace carbonyl compounds by means of an oximation reaction.  The chip can be used for directly preconcentrating carbonyl compounds in breath.  The concentrated ketone- and aldehyde-ATM adducts are analyzed by Fourier transform-ion cyclotron resonance (FT-ICR) mass spectrometry (MS) and gas chromatography-mass spectrometry (GC-MS).  The concentrations of all ketones and aldehydes in breath can be detemined by FT-ICR-MS and GC-MS.  We demonstrate the utility of this novel chip in the detection of   C1- to C12- ketones and aldehydes in exhaled breath.