Background: Exhaled breath is commonly used in alcohol testing but has been recently demonstrated by scientists from Sweden, Switzerland, and the United States to contain a large number of both volatile and nonvolatile substances that can be measured using dedicated devices. ExaBreath is a sampling device that collects the bio-aerosols particles from the donor. Approximately 1-2 minutes exhaled breath is enough for the test. The device collects the very small bio-aerosols on a filter, which is consecutively incubated into methanol to release the drugs at the laboratory.
Methods: Eighteen drug addicts from a methadone substitution program were recruited for this study. There were 5 women and 13 men, aged 25-50 years. The daily methadone dosage ranged from 10 to 120 mg, mostly as syrup. Urine (in plastic tubes with no preservative) and exhaled breath were simultaneously collected. In both fluids, methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) were tested using a specific liquid chromatographic-tandem mass spectrometric method, whereas all other compounds were screened by liquid chromatographic-tandem mass spectrometric method using a home made library of more than 800 compounds. Linearity, imprecision, and limit of quantitation were established. In each analytical batch, low and high controls were included.
Results: All 18 urine specimens tested positive for methadone and EDDP. Several other compounds were also identified, including morphine, THC-COOH, benzoylecgonine, nicotine, some antidepressants, and neuroleptics. Methadone and EDDP were identified in exhaled breath from all 18 patients, with concentrations in the range 11-1470 and 29-818 pg per filter, respectively. In 13 cases, the ratio methadone/EDDP in exhaled breath was >1 (range 0.4-2.8). Except nicotine (n = 7), no other substance was detectable in exhaled breath.
Conclusion: This study gives further support to the possibility of using exhaled breath as a new matrix to document exposure to drugs.