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The Mason Metabolomics Facility

Volatile Metabolites

Volatile organic compounds (VOCs) are a large and highly diverse

group of carbon-based molecules, generally related by their

volatility at ambient temperature.

The diagnostic potential of VOCs in biological specimens has

begun to receive considerable attention and correlations between

the

VOC metabolome

and various diseases are emerging,

including diabetes, asthma, cancer, and gastrointestinal disease.

Specialized sampling methods, such as headspace solid phase

microextraction (hSPME), have greatly facilitated the isolation of

VOCs from biological specimens.

A typical hSPME analysis involves the extraction of the

VOCs via partitioning into a polymeric coating adhered to

a fused silica rod (fiber), subsequent desorption of the

VOCs by heating the fiber in the injection port of a gas

chromatograph, separation of the VOCs by gas-liquid

partition chromatography (GC), and detection of the VOCs

via MS. Comparison to a mass spectral library permits

the identification of the extracted analytes.

While the polarity of the analyte of interest is typically used to

guide the selection of a particular SPME fiber, we recently have

shown that the multifarious nature of human biological sample

composition dictates the use of multiple SPME fibers for maximal

metabolomic coverage of the total VOCs. While this greatly

increases metabolite inclusion, multiple sample extractions are

then required, greatly increasing overall sample processing.

To address this issue, we have developed and patented an

innovative device that permits us to perform simultaneous

multifiber extractions of a biological sample (“simulti-hSPME”).

The device accommodates

all

of the commercially available fiber

types simultaneously, ensuring maximal VOC metabolome

coverage, while dramatically increasing the throughput of a VOC

metabolomics investigation.

An Example VOC Study:

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