abstract
Metabolomics represents an emerging issue that can aid in the diagnosis and/or prognosis of different diseases. Metabolomic study of urine is particularly interesting as it can be on the base of the developing of new faster and non-invasive methodologies. In response to this actual trend, comprehensive two-dimensional gas chromatography-time of flight mass spectrometry (GC x GC-ToFMS) combined with headspace solid phase microextraction (HS-SPME) is applied, for the first time to our knowledge, to the untargeted and comprehensive study of the volatile composition of human urine. From a total of ca. 700 compounds detected per sample. 294 were tentatively identified and distributed over the chemical families of hydrocarbons, amines. amides, esters, ketones, aldehydes, alcohols, carboxylic acids, ethers, nitriles, halides, sulfides, thiols, terpenoids, and heterocyclic compounds. To our knowledge, this is the most complete information available so far about whole human urine volatile composition, which represents a valuable data for future advanced studies in the clinical field based on urine fingerprinting. Relevant SPME and GC x GC parameters were considered. Complex sample characterization of human urine is significantly simplified due to the structured GC x GC chromatogram that produces distinct spaces for metabolite chemical families. Furthermore, the potential of this methodology in health related applications was explored by comparing the urinary volatile profiles between smoker (high-risk population for lung cancer) vs. non-smoker adults, focusing on metabolites related to oxidative stress (aliphatic alkalies and aldehydes). In spite of the small sample numbers considered, the results suggest that the urinary volatile profiles may be useful for differentiating subjects with different physiological conditions, thus making it worth to further explore its diagnostic potential. (C) 2012 Elsevier B.V. All rights reserved.
keywords
SOLID-PHASE MICROEXTRACTION; VOLATILE COMPOUNDS; SAMPLES; POWERFUL; TOOL; GC
subject category
Biochemistry & Molecular Biology; Chemistry
authors
Rocha, SM; Caldeira, M; Carrola, J; Santos, M; Cruz, N; Duarte, IF
our authors
Iola Melissa Fernandes Duarte
Principal Researcher
Joana Carolina Quintela Carrola
PhD Studentacknowledgements
Authors thank the Research Unit 62/94, QOPNA (project PEst-C/QUI/U10062/2011) and CICECO (project Pest-C/CTM/LA0011/2011) at the University of Aveiro for the financial support of this work. M. Caldeira thanks FCT (Fundacao para a Ciencia e Tecnologia) for his PhD grant (SFRH/BD/40374/2007) and I. F. Duarte thanks Liga Portuguesa Contra o Cancro for funding. The authors also wish to thank INDASA S.A (Aveiro, Portugal) for collaboration in the collection of samples.