Analysis of Volatile Organic Compounds in Human Saliva by a Static Sorptive Extraction Method and Gas Chromatography-Mass Spectrometry

Abstract

Human saliva not only helps control oral health (with anti-microbial proteins), but it may also play a role in chemical communication. As is the case with other mammalian species, human saliva contains peptides, proteins, and numerous volatile organic compounds (VOCs). A high-throughput analytical method is described for profiling a large number of saliva samples to screen the profiles of VOCs. Saliva samples were collected in a non-stimulated fashion. The method utilized static stir bar extraction followed by gas chromatography-mass spectrometry (GC-MS). The method provided excellent reproducibility for a wide range of salivary compounds, including alcohols, aldehydes, ketones, carboxylic acids, esters, amines, amides, lactones, and hydrocarbons. Furthermore, substantial overlap of salivary VOCs and the previously reported skin VOCs in the same subject group was found in this study by using pattern recognition analyses. Sensitivity, precision, and reproducibility of the method suggest that this technique has potential in physiological, metabolomic, pharmacokinetic, forensic, and toxicological studies of small organic compounds where a large number of human saliva samples are involved.

Assessment of the exhalation kinetics of volatile cancer biomarkers based on their physicochemical properties

“…• Benzophenone (CAS 119-61-9) was observed in the context of feces [131], axillary sweat [132] and saliva [133] and was suggested as a volatile biomarker for lung cancer [134].…”

“…• Trans-Caryophyllene (CAS 87-44-5) has been observed on the surface of juicy grapefruits [135], in feces [131], skin emanations [133], human breast milk and saliva [133,136].…”

Volatile Organic Compound and Metabolite Signatures as Pathogen Identifiers and Biomarkers of Infectious Disease

“…While the protein composition arising from each salivary gland is well characterized, the metabolite composition is not well understood. However, it has been determined that saliva contains numerous VOCs including alcohols, aldehydes, ketones, carboxylic acids, esters, amines, amides, lactones and hydrocarbons [18]. The various bacterial species found in the oral cavity also contribute to the chemical composition of saliva through secretion of their metabolic by-products.…”

Microfluidic optoelectronic sensor for salivary diagnostics of stomach cancer

“…Salivary diagnostics is much more convenient than biopsy or blood test: sample collection is simple, non-invasive and, therefore, not painful (Martin et al, 2012;Soini et al, 2010;Streckfus and Bigler, 2002). With respect to the gastric cancer screening, saliva is commonly analyzed for the presence of abnormal genetic material, or of specific biomarkers, which are detected by analyte-specific interactions using immunoassay arrays (Ivnitski et al, 2004;Jokerst et al, 2009;Tan et al, 2008).…”

“…It has been shown recently by means of gas chromatography/ mass spectrometry (GC-MS) that, just as in the case of exhaled breath, there are a variety of volatile compounds in saliva (Cao and Duan, 2006;Soini et al, 2010). Some volatile compounds found in exhaled breath, such as ammonia (NH 3 ) and carbon dioxide (CO 2 ), are related to gastric cancer (Lechner et al, 2005;Timmer et al, 2005;Xu et al, 2013).…”