Extractive Electrospray Ionization Mass Spectrometry For Exhaled Breath And Soil Analysis

Mass spectrometry has undergone a recent innovation known as ambient massspectrometry due to its ability to record mass spectra directly on samples in their naturalenvironments or matrices, without sample preparation. Extractive electrospray ionization(EESI), as one of the ambient ionization technique, is of interest for complex samplesanalysis due to its3-D space ionization mode which tolerates extremely complexmatrices. In-situ, rapid, real-time, online, non-invasive, in vivo analysis is coupled withhigh sensitivity and high specificity. Most types of samples (gas, liquid, solid) can beionized directly with great ease and simplicity. This advantageously applied to foodsafety, pharmaceutical analysis, environmental analysis, in vivo analysis, metabonomicsstudies and proteomics studies.Based on the brief overview of the ambient mass spectrometry and EESI technique,the main contents of this thesis are as follows:1. Chemical fingerprints of exhaled breath by EESI-MS. Mass spectralfingerprints of exhaled breath from healthy subjects and yin/yang/yin and yangdeficiency syndrome volunteers were recorded using optimized experimentalparameters. All data from the exhaled breath investigated were treated as onematrix and analyzed by principal component analysis (PCA). Then test theaccuracy of the three-dimensional model by an unknown exhaled breath sample.Chemical fingerprints of exhaled breath before and after consuming one cup ofcoffee were also obtained by EESI-MS. Elementary compositions (molecularformula) of target compounds were investigated by orbitrap mass spectrometer.2. Quantitative monitoring of exhaled Nitric Oxide (eNO) by EESI-MS. The acuteand short-term effects of cigarette smoking by both of smokers andnon-smokers on fractional concentration of nitric oxide in exhaled breath (FeNO) were measured in this work. Besides, FeNO of yin/yang/yin and yangdeficiency syndrome volunteers was much higher than healthy volunteers. AndeNO was predicted to be a biomarker of yin/yang/yin and yang deficiencysyndrome.3. A method based on EESI-MS was developed to obtain the mass spectra of threetypes of soil samples with minimal sample pre-treatment. The mass spectraclearly demonstrated the differences of organics among three types of soilsamples. Dehydroabietic acid and the combination of syringaldehyde andpinoresinol were detected in extracts of Pinus massoniana and Schima superbaGardn et. Champ. respectively by extractive electrosprary ionization tandemmass spectrometry (EESI-MS/MS). More interestingly, a new urea metabolite(3,3-diamino-3-hydroxypropanoic acid) was detected in soil extracts from therhizosphere of Pinus massoniana. And this study provides clues for futureresearch of nitrogen transformation processes in urea fertilized soils.