title: Analysis of volatile human urinary metabolome by solid-phase microextraction in combination with gas chromatography-mass spectrometry for biomarker discovery: application in a pilot study to discriminate patients with renal cell carcinoma.
abstract: A new and simple analytical approach consisting of headspace-solid phase microextraction (HS-SPME) sampling coupled with gas chromatography-ion trap/mass spectrometry (GC-IT/MS) was developed to study the volatile human urinary metabolome. A central composite design (CCD) was used in the optimisation of extraction conditions. Fibre selection and evaluation of pH influence were performed using an univariate mode and the influence of other parameters, such as the time and temperature of extraction, time of incubation and salt addition, that affect the efficiency of the SPME sampling, was carried out using a CCD. With a sample volume of 2 mL, the optimal conditions in terms of total response values and reproducibility were achieved by performing analyses with a divinylbenzene/polydimethylsiloxane (DVB/PDMS) fibre, in an acidic pH (pH 2) with the addition of 0.59 g of NaCl, allowing the sample to equilibrate for 9 min and extracting at 68 °C for 24 min. The applicability of the optimised method was then tested in a pilot non-target analysis of urine samples obtained from patients with renal cell carcinoma (RCC) and healthy individuals. Chemometric unsupervised analyses performed on the volatile pattern acquired for these samples clearly showed the potential of volatile urinary metabolome to discriminate between RCC and control patients.
authors.affiliation: REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal. Electronic address: aicram_monteiro@hotmail.com.
authors.forename: Márcia
authors.initials: M
authors.lastname: Monteiro
authors.affiliation: REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; CEBIMED, Faculdade de Ciências da Saúde, Universidade Fernando Pessoa, Porto, Portugal.
authors.forename: Márcia
authors.initials: M
authors.lastname: Carvalho
authors.affiliation: Cancer Biology & Epigenetics Group, Research Center of the Portuguese Oncology Institute - Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal; Department of Pathology, Portuguese Oncology Institute - Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal; Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal.
authors.forename: Rui
authors.initials: R
authors.lastname: Henrique
authors.affiliation: Cancer Biology & Epigenetics Group, Research Center of the Portuguese Oncology Institute - Porto, Rua Dr. António Bernardino de Almeida, Porto, Portugal; Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal.
authors.forename: Carmen
authors.initials: C
authors.lastname: Jerónimo
authors.affiliation: REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; CBQF - Center for Biotechnology and Fine Chemistry - Associated Laboratory, Faculty of Biotechnology, Catholic University of Portugal, Rua Dr. António Bernardino Almeida, 4200-072 Porto, Portugal.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Moreira
authors.affiliation: REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
authors.forename: Maria
authors.initials: M
authors.lastname: de Lourdes Bastos
authors.affiliation: REQUIMTE, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal. Electronic address: pguedes@ff.up.pt.
authors.forename: Paula Guedes
authors.initials: PG
authors.lastname: de Pinho
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000652:urine*; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000652:urine*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000652:urine*; D008297:Male; D055442:Metabolome; D008875:Middle Aged; D010865:Pilot Projects; D052617:Solid Phase Microextraction / Q000379:methods*
chemical_list: D014408:Biomarkers, Tumor
keywords: Central composite design; Gas chromatography-ion trap/mass spectrometry; Headspace solid-phase microextraction; Renal cell carcinoma; Urine; Volatile metabolomic profile