Measurement of natural carbon isotopic composition of acetone in human urine

• Published in: Analytical and bioanalytical chemistry 2016-02, Vol.408 (6), p.1597-1607
• Main Authors: Yamada, Keita, Ohishi, Kazuki, Gilbert, Alexis, Akasaka, Mai, Yoshida, Naohiro, Yoshimura, Ryoko
• Format: Article
• Language: English
• Subjects: Acetone; Acetone - chemistry; Acetone - urine; Analysis; Analytical Chemistry; Aqueous solutions; Biochemistry; Biological; Biological samples; Biomarkers; Carbon; Carbon Isotopes - urine; Characterization and Evaluation of Materials; Chemical properties; Chemistry; Chemistry and Materials Science; Diabetes; Fasting; Fatty acids; Female; Food Science; Gas chromatography; Gas Chromatography-Mass Spectrometry - methods; Glucose; headspace analysis; Human; Humans; Laboratory Medicine; liver; Male; Mass spectrometry; Metabolism; Metabolites; Middle Aged; Monitoring/Environmental Analysis; Physiology; Reagents; Research Paper; Solid Phase Microextraction; Temperature; Urine; Urine Specimen Collection - methods; VOCs; Volatile organic compounds; Young Adult
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-015-9268-z

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. Graphical abstract The natural carbon isotopic composition of acetone in urine can be determined using HS-SPME-GCC-IRMS and can provide information on changes in the availability of glucose in the liver.