Validating a breath collection and analysis system for the new tuberculosis breath test.

Mycobacterium tuberculosis releases four volatile compounds, methyl phenyl-acetate, methyl nicotinate, methyl p-anisate and o-phenylanisole, some of which we have previously been reported to be detected in the breath of tuberculosis patients (Syhre et al 2009 Tuberculosis 89 263-6). These volatiles have the potential to offer a non-invasive and sensitive breath test for the detection of tuberculosis infection. To determine the best sample collection and pre-concentration system a number of variables were examined. The four markers were most stable when breath was collected in a salinized glass sampling bulb compared to either Tedlar® TA, Supel(TM) Inert Foil or Supel(TM) Inert Gas bags. Concentration of breath onto thermal desorption cartridges indicated that Tenax® TA was the most universal sorbent for the collection of all four volatiles. Increasing the number of breath exhalations captured and analysed actively increased the detectable level of volatiles. The most important discovery was samples of methyl nicotinate, methyl p-anisate and o-phenylanisole remained stable on Tenax® TA cartridges for over two months at various altitudes.