Direct Detection of Acetonitrile in Human Breath by Extractive Electrospray Ionization Mass Spectrometry

Breath analysis by virtue of its potential medical research value, and as a non-invasive sample, simple sampling and continuous available is of interest for modern clinical diagnosis and metabonomics. The concentration levels of acetonitrile, an important biomarker in human exhaled gas, are correlated with human health. Herein we constructed a novel platform of extractive electrospray ionization-mass spectrometry (EESI-MS) for direct, rapid detection of acetonitrile in human breath without any sample pretreatment. Under the optimized working conditions, the quantitative information of acetonitrile in human breath was acquired effectively. For acetonitrile, a limit of detection was found to be 5. 71 pL/L; the linear range was from 76. 4 pL/L to 1910 pL/L. The concentration of acetonitrile in the exhaled breath of two healthy volunteers was in vivo determined to be 134. 49 and 104. 40 pL/L, respectively, the relative standard deviations were 6. 3% and 7. 2%. The results show that EESI-Ion Trap MS is a powerful analytical platform to provide high sensitivity, high precision, rapid analysis and high specificity for semi-quantitative analysis of acetonitrile in human breath, and for detection of other bio-molecules in exhaled breath potentially.