title: LC/ESI-MS/MS method for determination of salivary eicosapentaenoic acid concentration to arachidonic acid concentration ratio.
abstract: A simple liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) method for determination of the eicosapentaenoic acid (EPA) concentration to arachidonic acid (AA) concentration ratio in human saliva has been developed. The EPA/AA ratio in serum or plasma is widely recognized as a useful indicator in identifying the risk of cardiovascular disease, especially atherosclerosis. The salivary EPA/AA ratio is expected to be a convenient alternative to the serum or plasma EPA/AA ratio, because saliva offers the advantages of easy and noninvasive sampling. The saliva was deproteinized with acetonitrile, purified using an Oasis HLB cartridge, and derivatized with 1-[(4-dimethylaminophenyl)carbonyl]piperazine (DAPPZ). The derivatized EPA and AA were subjected to LC/ESI-MS/MS, and the EPA/AA ratio was determined using the selected reaction monitoring mode. The DAPPZ-derivatization increased the ESI sensitivity by 100- and 300-fold for EPA and AA, respectively, and enabled the detection of trace fatty acids in saliva using a 200 μL sample. The assay reproducibility was satisfactory (relative standard deviation, <5.0%). The method was successfully applied to the measurement of the salivary EPA/AA ratios of healthy Japanese subjects and their changes owing to the supplementation of EPA.
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan.
authors.forename: Shoujiro
authors.initials: S
authors.lastname: Ogawa
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan.
authors.forename: Koki
authors.initials: K
authors.lastname: Tomaru
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan.
authors.forename: Nagisa
authors.initials: N
authors.lastname: Matsumoto
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan.
authors.forename: Shui
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Higashi
mesh_terms: D000328:Adult; D016718:Arachidonic Acid / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D019587:Dietary Supplements / Q000032:analysis; D015118:Eicosapentaenoic Acid / Q000032:analysis* / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D012463:Saliva / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D055815:Young Adult
chemical_list: D016718:Arachidonic Acid; D015118:Eicosapentaenoic Acid
keywords: arachidonic acid; concentration ratio; derivatization; eicosapentaenoic acid; liquid chromatography/electrospray ionization-tandem mass spectrometry; saliva