Analysis of a Broad Range of Carbonyl Metabolites in Exhaled Breath by UHPLC-MS

Abstract

Analysis of volatile organic compounds (VOCs) in exhaled breath (EB) has shown great potential for disease detection including lung cancer, infectious respiratory diseases, and chronic obstructive pulmonary disease. Although many breath sample collection and analytical methods have been developed for breath analysis, analysis of metabolic VOCs in exhaled breath is still a challenge for clinical application. Many carbonyl compounds in exhaled breath are related to the metabolic processes of diseases. This work reports a method of ultrahigh-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-MS) for the analysis of a broad range of carbonyl metabolites in exhaled breath. Carbonyl compounds in the exhaled breath were captured by a fabricated silicon microreactor with a micropillar array coated with 2-(aminooxy)ethyl-N,N,Ntrimethylammonium (ATM) triflate. A total of six subgroups consisting of saturated aldehydes and ketones, hydroxy-aldehydes, and hydroxy-ketones, unsaturated 2-alkenals, and 4-hydroxy-2-alkenals were identified in the exhaled breath. The combination of a silicon microreactor for the selective capture of carbonyl compounds with UHPLC-MS analysis may provide a quantitative method for the analysis of carbonyls to identify disease markers in exhaled breath.

Simultaneous Detection of Aldehyde Metabolites by Light-Assisted Ambient Ionization Mass Spectrometry

“…In clinic, only one metabolite detection is normally unreliable and normally requires joint detection of multiple metabolites. , Moreover, in some cases, more than one kind of aldehydes may exist in the disease. ,, Thus, we further explored the possibility of this light-assisted strategy for several aldehyde metabolites coexisting in one sample simultaneous identification. Without loss of generality, Val, Hep, 2-Fur, 10-Und, and Ben in ammonium acetate buffer were mixed with the Se nanoprobe followed by light-assisted AIMS detection.…”

“…22,23 Moreover, it has been reported that aldehydes with very small molecular (less than six carbon atoms) or large molecular (more than 10 carbon atoms) weights are difficult to be detected. 6,24,25 Chemical isotope labeling (CIL) has demonstrated great success in mass spectrometry (MS) with enhanced sensitivity and accuracy. 26,27 In addition, selenium compared with other elements is easily recognized because of its characteristic isotope peak distribution in the MS spectrum.…”

“…Val has been proved to be a sensitive indicator of gastric cancer . However, despite the high significance of aldehydes in determination of many physiological and pathological processes, sensitivity analysis of aldehydes in biological samples (especially blood) is still challenging because of the trace levels of aldehyde and the complicated compositions in the sample. − More importantly, the disease-relevant aldehydes are a large family with diverse chemical structures, including alkane chain-saturated aldehydes, unsaturated aldehydes, dialdehydes, and aromatic aldehydes. , Moreover, it has been reported that aldehydes with very small molecular (less than six carbon atoms) or large molecular (more than 10 carbon atoms) weights are difficult to be detected. ,, …”

Identification of a marker of infection in the breath using a porcine pneumonia model

“…A quaternary ammonium compound, 2-(aminooxy)ethyl- N,N,N -trimethylammonium (ATM) triflate, was used to coat the surfaces of the micropillars as previously described. 9 , 17 , 18 ATM adsorbs to the silicon dioxide surfaces of the micropillars via electrostatic and hydrogen bond interactions. ATM chemoselectively traps carbonyl compounds in exhaled breath by means of oximation reactions.…”

“…The procedure for the capture of carbonyl compounds in air and exhaled breath has been described previously. 9 , 17 , 18 To summarize, the exhaled breath collected in 1-L Tedlar bags was drawn through the microreactor chip by applying a vacuum at a flow rate of 7 mL/min. After this process, ATM adducts in the microreactors were eluted with 200 μL of water from a slightly pressurized small vial.…”