Fingerprinting A Person's Breath
April 4, 2013

Converted Mass Spectrometer Can Pinpoint Your ‘Breathprint’

Brett Smith for - Your Universe Online

Doctors routinely use blood or urine samples to test for signs of illness or disease and a new study from a group of Swiss researchers indicates that a person´s breath could soon be added to that list.

According to the study, which appeared in the open-access journal PLOS ONE, the researchers were also able to discriminate between individual breath signatures as if they were fingerprints.

Previous research has shown that trained dogs and rats can smell a person´s breath and determine if they have certain kinds of cancer. In the new study, researchers from the Swiss Federal Institute of Technology (ETH) and the University Hospital Zürich wanted to see if a mass spectrometer could be modified to perform a similar function.

The ETH chemists attached a breath sampling inlet line that delivers breath directly into a spectrometer´s sampling device, allowing them to measure the approximately 100 compounds in breath.

Using samples from eleven volunteers, the Swiss scientists initially found out that each individual had his or her own breath signature, which was based on the presence and amounts of volatile and semi-volatile metabolites. The researchers were able to identify several key biomarkers such as acetone, a product of the sugar metabolism.

"We did find some small variations during the day, but overall the individual pattern stays sufficiently constant to be useful for medical purposes,” said co-author Pablo Martinez-Lozano Sinues, from the Department of Chemistry and Applied Biosciences at ETH Zurich.

While other biomarkers in the "breathprints" have yet to be assigned, the scientists said they plan to expand their ability to identify an individual by their breath.

In addition to using the technology to identify a person, the ETH scientists said they plan to recognize tell-tale patterns of diseases based on biomarkers in a breath sample. For this part of the research project, they are collaborating with medical doctors at the Division of Pulmonology of the University Hospital Zurich, according to a recent statement.

"If we find a consistent pattern in patients with a given lung disease, we can develop a diagnostic tool,” said Sinues.

According to the scientists, identifying lung diseases will be their top priority as they will be the most likely to present the clearest evidence. Once they can identify lung diseases, the scientist said they plan to expand their methodology to other diseases.

Breath analysis poses a significant advantage in that it is available within seconds, while analyzing urine or blood typically takes longer. Another advantage of breath analysis is that it is completely non-invasive.

"Our goal is to develop breath analysis to the point where it becomes competitive with the established analysis of blood and urine,” said co-author Malcolm Kohler, a professor at the University Hospital Zurich.

The research team noted that the instrumentation has to be improved before their methodology can be extended, as mass spectrometers they are currently using are large and expensive.

"Small, portable mass spectrometers already exist; if their performance can be improved, they will eventually find their way into clinics and doctor's offices,” said lead author Renato Zenobi, from ETH Zurich.