| Title: | Water-Resistant Polymeric Acid Membrane Catalyst for Acetone Detection in the Exhaled Breath of Diabetics |
| Author(s): | Worrall AD; Qian Z; Bernstein JA; Angelopoulos AP; |
| Address: | "Department of Biomedical, Chemical, and Environmental Engineering, University of Cincinnati , Cincinnati, Ohio 45221, United States. Department of Internal Medicine, Division of Immunology, College of Medicine, University of Cincinnati , Cincinnati, Ohio 45221, United States" |
| DOI: | 10.1021/acs.analchem.7b03808 |
| ISSN/ISBN: | 1520-6882 (Electronic) 0003-2700 (Linking) |
| Abstract: | "Endogenous volatile organic compounds (VOCs) such as acetone in exhaled human breath are associated with metabolic conditions in the bloodstream. Development of compact, rapid detectors of exhaled breath chemical composition in clinical settings is challenging due to the small sample size that can be collected during a single exhalation as well as spectroscopic interference by the abundance of water. In this paper, we show that the activity of a catalytic polymer membrane (Nafion 117) toward the heterogeneous condensation reaction of immobilized resorcinol reagent with gas-phase acetone can be preserved even at 100% ambient relative humidity through the incorporation of organic acids such as vanillic or tiglic. The reaction produces a colored flavan product that permits highly selective and sensitive correlation to acetone concentration in exhaled breath. Such behavior suggests solvent displacement, analogous to homogeneous liquid-phase systems. However, unlike classic acid-base equilibria, the extent of optode water resistance is shown to increase with the pK(a) of the imbibed organic acid while peak signal intensity of the imbibed acid undergoes a bathochromic shift to longer wavelengths. These observations are consistent with competition between organic acid deprotonation by water in a mixed solvent system on the one hand and immobilization on the other. Finally, we demonstrate how when applied to the direct chemical analysis of acetone in exhaled human breath, the approach yields excellent correlation to blood glucose in diabetics" |
| Keywords: | "Acetone/*analysis/chemistry Adult Aged Aged, 80 and over Breath Tests/*instrumentation/methods Catalysis Diabetes Mellitus/metabolism Female Fluorocarbon Polymers/*chemistry Humans Kinetics Male Middle Aged Resorcinols/chemistry Young Adult;" |
| Notes: | "MedlineWorrall, Adam D Qian, Zexin Bernstein, Jonathan A Angelopoulos, Anastasios P eng Research Support, Non-U.S. Gov't 2017/12/28 Anal Chem. 2018 Feb 6; 90(3):1819-1826. doi: 10.1021/acs.analchem.7b03808. Epub 2018 Jan 17" |
