Quantitative detection of nitric oxide in exhaled human breath by extractive electrospray ionization mass spectrometry.

Abstract

Exhaled nitric oxide (eNO) is a useful biomarker of various physiological conditions, including asthma and other pulmonary diseases. Herein a fast and sensitive analytical method has been developed for the quantitative detection of eNO based on extractive electrospray ionization mass spectrometry (EESI-MS). Exhaled NO molecules selectively reacted with 2-phenyl-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) reagent, and eNO concentration was derived based on the EESI-MS response of 1-oxyl-2-phenyl-4, 4, 5, 5-tetramethylimidazoline (PTI) product. The method allowed quantification of eNO below ppb level (~0.02 ppbv) with a relative standard deviation (RSD) of 11.6%. In addition, eNO levels of 20 volunteers were monitored by EESI-MS over the time period of 10 hrs. Long-term eNO response to smoking a cigarette was recorded, and the observed time-dependent profile was discussed. This work extends the application of EESI-MS to small molecules (<30 Da) with low proton affinity and collision-induced dissociation efficiency, which are usually poorly visible by conventional ion trap mass spectrometers. Long-term quantitative profiling of eNO by EESI-MS opens new possibilities for the research of human metabolism and clinical diagnosis.

• Authors: Susu Pan, Yong Tian, Ming Li, Jiuyan Zhao, Lanlan Zhu, Wei Zhang, Haiwei Gu, Haidong Wang, Jianbo Shi, Xiang Fang, Penghui Li, Huanwen Chen
• Journal: Scientific reports (Sci Rep) Vol. 5 Pg. 8725 (Mar 04 2015) ISSN: 2045-2322 [Electronic] England
• PMID: 25735640 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cyclic N-Oxides
• Imidazoles
• 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide
• Nitric Oxide

Topics

• Algorithms
• Breath Tests (methods)
• Cyclic N-Oxides (chemistry)
• Exhalation
• Humans
• Imidazoles (chemistry)
• Models, Chemical
• Nitric Oxide (analysis, chemistry)
• Smoking
• Spectrometry, Mass, Electrospray Ionization (methods)