title: Keto acids in tissues and biological fluids: O-t-butyldimethylsilyl quinoxalinols as derivatives for sensitive gas chromatographic/mass spectrometric determination.
abstract: Quinoxalinol t-butyldimethylsilyl ethers were prepared from three branched-chain and from two aliphatic unbranched 2-keto acids. The electron impact (EI) mass spectra display pronounced [M-57]+ ions. With 39-51% of total ion current contained within them, sensitivity is greater than on chemical ionization (CI) mass spectrometry of O-trimethylsilyl derivatives. Mass spectra and chromatographic behaviour of these novel keto acid derivatives are discussed and preliminary quantitative data from rat muscle are given.
authors.forename: U
authors.initials: U
authors.lastname: Langenbeck
authors.forename: H
authors.initials: H
authors.lastname: Luthe
authors.forename: G
authors.initials: G
authors.lastname: Schaper
mesh_terms: D000818:Animals; D001826:Body Fluids / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D007651:Keto Acids / Q000032:analysis* / Q000378:metabolism; D009132:Muscles / Q000032:analysis / Q000378:metabolism; D011810:Quinoxalines; D051381:Rats; D012825:Silicon
chemical_list: D007651:Keto Acids; D011810:Quinoxalines; D012825:Silicon