title: Solid phase extraction procedure for urinary organic acid analysis by gas chromatography mass spectrometry.
abstract: We have developed a solid phase extraction procedure for the detection of organic acids by GC-MS using a strong anion exchange column (Sep-Pak Vac RC, Accell Plus QMA cartridge). Extraction efficiencies of 25 organic acids were established by analyzing standards in water based solutions. High extraction efficiencies (90 to 100%) were found for many of the compounds studied. We estimated the limit of detection for 48 organic acids and glycine conjugates. They were below 5 nmole with the exception of malonic and oxalic acids and mevalonic acid lactone. This method provides the advantage of higher recoveries for a wide range of compounds of interest and therefore can be a potential alternative to liquid-liquid extraction for organic acid screening. It is especially sensitive for the detection of some polar compounds, such as 3-OH-glutaric and N-acetylaspartic acids.
authors.affiliation: ARUP Institute for Clinical and Experimental Pathology, 500 Chipeta Way, Salt Lake City, UT 84108, USA. liua@aruplab.com
authors.forename: Aiping
authors.initials: A
authors.lastname: Liu
authors.forename: Mark M
authors.initials: MM
authors.lastname: Kushnir
authors.forename: William L
authors.initials: WL
authors.lastname: Roberts
authors.forename: Marzia
authors.initials: M
authors.lastname: Pasquali
mesh_terms: D000143:Acids / Q000652:urine*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D009930:Organic Chemicals / Q000652:urine*
chemical_list: D000143:Acids; D009930:Organic Chemicals