Novel extraction of volatile biomarkers from canine breath for gas chromatography–mass spectrometry

Abstract

Here we describe an effective, reproducible, non-invasive volatile organic compound collection and analysis method for exhaled breath gas samples designed specifically for use with dogs. Conditions of the method were optimized, using a range of standard chemicals. This method utilizes a canine mask, two-way non-re-breathing valve, teflon connector, tubing and bag for sample collection. Collection is followed by condensation and headspace solid phase microextraction for sample concentration and gas chromatography-mass spectrometry for analysis. Custom-made glassware, designed to hold the SPME fiber assembly, was cooled to -10 °C and used for the collection of the condensate followed by 2 h of headspace extraction at 37 °C. Standards show LOD of 0.6-16.8 ppbv, LOQ between 2.1-55.8 ppbv, and good linearity with R(2) between 0.996-0.999 (RSD% 10-19). The method was verified with preliminary results from three dogs demonstrating that this technique is capable of collecting, identifying and quantifying volatile organic chemical constituents in different breath samples.

Review on Volatolomic Studies as a Frontier Approach in Animal Research

“…Custom‐made masks adapted to cover animal's face were designed for dogs, [ 25 ] while semiclosed chamber systems were used to collect breath samples in both dogs and cats. [ 26,27 ] For breath sample measurement, the exhaled air was pumped directly from the mask into a portable respiratory air monitoring system.…”

“…[ 26,27 ] Alternatively, the breath samples were first condensed on a glassware wall and then transferred to the SPME fiber after heating the glassware at 37 °C for VOCs release. [ 25 ]…”