title: An efficient and robust fatty acid profiling method for plasma metabolomic studies by gas chromatography-mass spectrometry.
abstract: BACKGROUND
  Targeted metabolomic analysis of fatty acids has linked the dysregulation of fatty acids to many diseases. This study selected five frequently used fatty acid derivatization methods for comparison.
  
  
  METHODS
  We compared the method precisions and derivatization efficiencies, the most economical and best performing method was subjected to method validation. Twenty-four fatty acid standards were used to validate the method, which was later applied to the investigation of potential fatty acid markers of breast cancer.
  
  
  RESULTS
  The acetyl chloride method was demonstrated to provide the best derivatization efficiency and lowest cost for plasma samples. The ionic liquid column successfully separated positional and geometric fatty acid isomers within 26 min under the optimized conditions. Intra-day and inter-day CVs for most of the fatty acids were <10%. Over 90% of the results showed recoveries within 85%-115%. The validated method was applied to investigate potential fatty acid markers of breast cancer. The fatty acid profiling results revealed that 3 fatty acids (C22:0, C24:0, C18:2n6) were significantly lower in both pre- and post-menopausal breast cancer patients (P<0.05).
  
  
  CONCLUSIONS
  We demonstrated that the proposed method is an accurate, efficient and economical method for plasma metabolomic studies of fatty acids.
authors.affiliation: School of Pharmacy, College of Medicine, National Taiwan University, Taiwan.
authors.forename: Huai-Hsuan
authors.initials: HH
authors.lastname: Chiu
authors.affiliation: School of Pharmacy, College of Medicine, National Taiwan University, Taiwan.
authors.forename: Sung-Jeng
authors.initials: SJ
authors.lastname: Tsai
authors.affiliation: Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taiwan; The Metabolomics Core Laboratory, Center of Genomic Medicine, National Taiwan University, Taiwan.
authors.forename: Y Jane
authors.initials: YJ
authors.lastname: Tseng
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taiwan.
authors.forename: Ming-Shiang
authors.initials: MS
authors.lastname: Wu
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital, Taiwan.
authors.forename: Wei-Chih
authors.initials: WC
authors.lastname: Liao
authors.affiliation: Department of Surgery, National Taiwan University Hospital, Taiwan. Electronic address: huangcs@ntu.edu.tw.
authors.forename: Chiun-Sheng
authors.initials: CS
authors.lastname: Huang
authors.affiliation: School of Pharmacy, College of Medicine, National Taiwan University, Taiwan; The Metabolomics Core Laboratory, Center of Genomic Medicine, National Taiwan University, Taiwan; Department of Pharmacy, National Taiwan University Hospital, Taiwan. Electronic address: kuoch@ntu.edu.tw.
authors.forename: Ching-Hua
authors.initials: CH
authors.lastname: Kuo
mesh_terms: D001943:Breast Neoplasms / Q000097:blood / Q000378:metabolism; D005227:Fatty Acids / Q000097:blood* / Q000378:metabolism*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D055432:Metabolomics
chemical_list: D005227:Fatty Acids
keywords: Breast cancer; Derivatization; Fatty acid; GC-MS; Plasma