title: Application of gas chromatography-tandem mass spectrometry (GC/MS/MS) for the analysis of deuterium enrichment of water.
abstract: Incorporation of deuterium from deuterium oxide ((2) H2 O) into biological components is a commonly used approach in metabolic studies. Determining the dilution of deuterium in the body water (BW) pool can be used to estimate body composition. We describe three sensitive GC/MS/MS methods to measure water enrichment in BW. Samples were reacted with NaOH and U-(13) C3 -acetone in an autosampler vial to promote deuterium exchange with U-(13) C3 -acetone hydrogens. Headspace injections were made of U-(13) C3 -acetone-saturated air onto a 30-m DB-1MS column in electron impact-mode. Subjects ingested 30 ml (2) H2 O, and plasma samples were collected. BW was determined by standard equation. Dual-energy X-ray absorptiometry scans were performed to calculate body mass, body volume and bone mineral content. A four-compartmental model was used to estimate body composition (fat and fat free mass). Full-scan experiments generated an m/z 45 peak and to a lesser extent an m/z 61 peak. Product fragment ions further monitored included 45 and 46 using selected ion monitoring (Method1), the 61 > 45 and 62 > 46 transition using multiple reaction monitoring (MRM; Method2) and the neutral loss, 62 > 45, transition (Method3). MRM methods were optimized for collision energy (CE) and collision-induced dissociation (CID) argon gas pressure with 6 eV CE and 1.5 mTorr CID gas being optimal. Method2 was used for final determination of (2) H2 O enrichment of subjects because of lower natural background. We have developed a sensitive method to determine (2) H2 O enrichment in BW to enable measurement of FM and FFM.
authors.affiliation: Center for Translational Research in Aging and Longevity, Department of Health & Kinesiology, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Dillon K
authors.initials: DK
authors.lastname: Walker
authors.affiliation: Center for Translational Research in Aging and Longevity, Department of Health & Kinesiology, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: John J
authors.initials: JJ
authors.lastname: Thaden
authors.affiliation: Center for Translational Research in Aging and Longevity, Department of Health & Kinesiology, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Nicolaas E P
authors.initials: NE
authors.lastname: Deutz
mesh_terms: D000096:Acetone; D000328:Adult; D000368:Aged; D001834:Body Water / Q000737:chemistry* / Q000378:metabolism; D003903:Deuterium / Q000097:blood* / Q000378:metabolism; D017666:Deuterium Oxide / Q000737:chemistry* / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D053719:Tandem Mass Spectrometry / Q000379:methods; D055815:Young Adult
chemical_list: D000096:Acetone; D003903:Deuterium; D017666:Deuterium Oxide
keywords: acetone; body composition; deuterium; gas chromatography; tandem mass spectrometry