Real-time monitoring of exhaled volatiles using atmospheric pressure chemical ionization on a compact mass spectrometer.

Aim: Breath analyses have potential to detect early signs of disease onset. Ambient ionization allows direct combination of breath gases with MS for fast, on-line analysis. Portable MS systems would facilitate field/clinic-based breath analyses.

How long may a breath sample be stored for at -80 °C? A study of the stability of volatile organic compounds trapped onto a mixed Tenax:Carbograph trap adsorbent bed from exhaled breath.

Thermal desorption is used extensively in exhaled breath volatile organic compound (VOC) analysis, and it is often necessary to store the adsorbent tube samples before analysis. The possible introduction of storage artefacts is an important potential confounding factor in the development of standard methodologies for breath sampling and analysis. The stability of VOCs trapped from breath samples onto a dual bed Tenax(®) TA:Carbograph adsorbent tube and stored  -80°C was studied over 12.

Analysis of human breath samples using a modified thermal desorption: gas chromatography electrospray ionization interface.

A two-stage thermal desorption/secondary electrospray ionization/time-of-flight mass spectrometry for faster targeted breath profiling has been studied. A new secondary electrospray ionization (SESI) source was devised to constrain the thermal desorption plume and promote efficient mixing in the ionization region. Further, a chromatographic pre-separation stage was introduced to suppress interferences from siloxanes associated with thermal desorption profiles of exhaled breath samples.

Metabolomics pilot study to identify volatile organic compound markers of childhood asthma in exhaled breath.

Background: In-community non-invasive identification of asthma-specific volatile organic compounds (VOCs) in exhaled breath presents opportunities to characterize phenotypes, and monitor disease state and therapies. The feasibility of breath sampling with children and the preliminary identification of childhood asthma markers were studied.

Method: End-tidal exhaled breath was sampled (2.

Determination of biogenic diamines with a vaporisation derivatisation approach using solid-phase microextraction gas chromatography-mass spectrometry.

A gas-phase on-fibre derivatisation method for the determination of putrescine and cadaverine by gas chromatography/mass spectrometry using trifluoroacetylacetone (TFAA) has been studied and optimised. Small amounts (2μl) of putrescine, cadaverine and TFAA standards were vaporised at high temperature in a 20cm(3) closed SPME vial. The subsequent derivatives were recovered from the headspace of the vial using a PDMS/DVB fibre.