title: Measurement of natural carbon isotopic composition of acetone in human urine.
abstract: The natural carbon isotopic composition of acetone in urine was measured in healthy subjects using gas chromatography-combustion-isotope ratio mass spectrometry combined with headspace solid-phase microextraction (HS-SPME-GC-C-IRMS). Before applying the technique to a urine sample, we optimized the measurement conditions of HS-SPME-GC-C-IRMS using aqueous solutions of commercial acetone reagents. The optimization enabled us to determine the carbon isotopic compositions within ±0.2 ‰ of precision and ±0.3‰ of error using 0.05 or 0.2 mL of aqueous solutions with acetone concentrations of 0.3-121 mg/L. For several days, we monitored the carbon isotopic compositions and concentrations of acetone in urine from three subjects who lived a daily life with no restrictions. We also monitored one subject for 3 days including a fasting period of 24 h. These results suggest that changes in the availability of glucose in the liver are reflected in changes in the carbon isotopic compositions of urine acetone. Results demonstrate that carbon isotopic measurement of metabolites in human biological samples at natural abundance levels has great potential as a tool for detecting metabolic changes caused by changes in physiological states and disease.
authors.affiliation: Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan. yamada.k.ag@m.titech.ac.jp.
authors.forename: Keita
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Ohishi
authors.affiliation: Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan.
authors.forename: Alexis
authors.initials: A
authors.lastname: Gilbert
authors.affiliation: Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan.
authors.forename: Mai
authors.initials: M
authors.lastname: Akasaka
authors.affiliation: Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan.|Earth-Life Science Institute, Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan.
authors.forename: Naohiro
authors.initials: N
authors.lastname: Yoshida
authors.affiliation: NTT Device Innovation Center, NTT Corporation, 3-1, Morinosato Wakamiya, Atsugi, Kanagawa, 243-0198, Japan.
authors.forename: Ryoko
authors.initials: R
authors.lastname: Yoshimura
mesh_terms: D000096:Acetone / Q000737:chemistry / Q000652:urine*; D002247:Carbon Isotopes / Q000652:urine*; D005215:Fasting; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D052617:Solid Phase Microextraction; D013696:Temperature; D059349:Urine Specimen Collection / Q000379:methods; D055815:Young Adult
chemical_list: D002247:Carbon Isotopes; D000096:Acetone
keywords: Acetone; Carbon isotopic compositions; Diabetes; Metabolites; Urine