Title: | Direct human breath analysis by secondary nano-electrospray ionization ultrahigh-resolution mass spectrometry: Importance of high mass resolution and mass accuracy |
Author(s): | Li X; Huang L; Zhu H; Zhou Z; |
Address: | "Institute of Mass Spectrometry and Atmospheric Environment, Jinan University, Guangzhou, 510632, China. Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air Pollution, Guangzhou, 510632, China. Guangzhou Hexin Instrument Co., Ltd, Guangzhou, 510530, China" |
Journal Title: | Rapid Commun Mass Spectrom |
ISSN/ISBN: | 1097-0231 (Electronic) 0951-4198 (Linking) |
Abstract: | "RATIONALE: Direct mass spectrometry (MS)-based methods make it possible to monitor the molecular compositions of hundreds of volatile organic compounds (VOCs) in exhaled human breath in real time. Mass resolution and mass accuracy play important roles for direct MS analysis, especially for the low-concentration isobaric compounds in non-target research. METHODS: Direct detection of VOCs in exhaled breath of four healthy subjects (3 males and 1 female aged between 25 to 35 years old) has been performed by using secondary nano-electrospray ionization mass spectrometry (Sec-nanoESI-UHRMS) at resolutions (R) of 15,000, 30,000, 60,000 and 120,000. RESULTS: For some low-intensity isobaric ions, they could be distinguished only when R >/= 60,000, e.g., signals at m/z 96.9591 (sulfate/sulfuric acid), m/z 96.9687 (phosphate/phosphoric acid) and m/z 96.9756 ([C(4) H(2) O(7) S](-) ), m/z 234.1161 ([C(10) H(20) O(3) NS](+) ) and m/z 234.1338 ([C(10) H(20) O(5) N](+) ), m/z 119.0686 (isotope of indole) and m/z 119.0705 (an interfering signal), respectively. At R 120,000, the mass errors were obtained from a set of reference ions, and the values were /=60,000 and mass errors of 1.0 mDa (absolute value) covering the mass range of interests (e.g., m/z 50-500) are necessary for the exploration and accurate identification of low-intensity unknown isobaric compounds in non-target research. Copyright (c) 2017 John Wiley & Sons, Ltd" |
Notes: | "PubMed-not-MEDLINELi, Xue Huang, Lei Zhu, Hui Zhou, Zhen eng England 2016/11/20 Rapid Commun Mass Spectrom. 2017 Feb 15; 31(3):301-308. doi: 10.1002/rcm.7794" |