title: Determination of red blood cell fatty acid profiles: Rapid and high-confident analysis by chemical ionization-gas chromatography-tandem mass spectrometry.
abstract: Cellular fatty acid (FA) profiles have been acknowledged as biomarkers in various human diseases. Nevertheless, common FA analysis by gas chromatography mass spectrometry (GC-MS) requires long analysis time. Hence, there is a need for feasible methods for high throughput analysis in clinical studies. FA was extracted from red blood cells (RBC) and derivatized to fatty acid methyl esters (FAME). A method using gas chromatography tandem mass spectrometry (GC-MS/MS) with ammonia-induced chemical ionization (CI) was developed for the analysis of FA profiles in human RBC. We compared this method with classical single GC-MS using electron impact ionization (EI). The FA profiles of 703 RBC samples were determined by GC-MS/MS. In contrast to EI ammonia-induced CI resulted in adequate amounts of molecular ions for further fragmentation of FAME. Specific fragments for confident quantification and fragmentation were determined for 45 FA. The GC-MS/MS method has a total run time of 9min compared to typical analysis times of up to 60min in conventional GC-MS. Intra and inter assay variations were <10% for all FA analyzed. Analysis of RBC FA composition revealed an age-dependent increase of the omega-3 eicosapentaenoic and docosahexaenoic acid, and a decline of the omega-6 linoleic acid with a corresponding rise of the omega-3 index. The combination of ammonia-induced CI and tandem mass spectrometry after GC separation allows for high-throughput, robust and confident analysis of FA profiles in the clinical laboratory.
authors.affiliation: Institute of Laboratory Medicine and Pathobiochemistry, Philipps-University Marburg, Germany.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Schober
authors.affiliation: Institute of Laboratory Medicine and Pathobiochemistry, Philipps-University Marburg, Germany; Medizinisches Labor Wahl, Lüdenscheid, Germany.
authors.forename: Hans Günther
authors.initials: HG
authors.lastname: Wahl
authors.affiliation: Institute of Laboratory Medicine and Pathobiochemistry, Philipps-University Marburg, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Renz
authors.affiliation: Institute of Laboratory Medicine and Pathobiochemistry, Philipps-University Marburg, Germany. Electronic address: nockher@med.uni-marburg.de.
authors.forename: Wolfgang Andreas
authors.initials: WA
authors.lastname: Nockher
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004912:Erythrocytes / Q000737:chemistry*; D005227:Fatty Acids / Q000032:analysis*; D015525:Fatty Acids, Omega-3 / Q000032:analysis; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000191:economics / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D053719:Tandem Mass Spectrometry / Q000191:economics / Q000379:methods; D055815:Young Adult
chemical_list: D005227:Fatty Acids; D015525:Fatty Acids, Omega-3
keywords: Chemical ionization; Fatty acids; Gas chromatography; High-throughput analysis; Tandem mass spectrometry