(308c) A Novel MEMS Preconcentration Approach for Analysis of Ketones and Aldehydes In Breath

A Novel MEMS Preconcentration
Approach for Analysis of Ketones and Aldehydes in Breath

Mingxiao Li^a, Souvik Biswas^b,
Michael H. Nantz^b, Richard M. Higashi^b,c,d,  Xiao-An Fu^*a,

Departments of ¹Chemical Engineering and ²Chemistry,
³Center for Regulatory and Environmental Analytical Metabolomics
(CREAM), and ⁴ James Graham Brown Cancer Center,

The analysis of exhaled breath is a promising non-invasive diagnostic
method for early detection of lung diseases. Certain volatile organic compounds
(VOCs), such as ketones and aldehydes in exhaled breath, have already been
recognized as metabolic indicators of many diseases including lung cancer and
chronic obstructive pulmonary disease (COPD).

We report a MEMS-based micropreconcentrator
that has been engineered to selectively preconcentrate
ultra-trace gaseous ketones and aldehydes
in exhaled breath. The silicon-glass micro-preconcentrator
has outer dimensions of 14mm×14 mm, total inner surface area of ~300mm²,
and a total inner volume of ~7 µL. The surface of the preconcentrator
is functionalized with a quaternary ammonium aminooxy
compound, for preconcentrating trace carbonyl VOCs by
means of an oximation reaction. The concentrated ketone- and aldehyde- adducts are
directly analyzed by Fourier transform-ion cyclotron resonance (FT-ICR) mass
spectrometer (MS). We demonstrate the utility and enhanced sensitivity of this
approach in the detection of  C1- to C12 ketones and aldehydes in exhaled breath.