title: Ammonia-treated N-(1-naphthyl) ethylenediamine dihydrochloride as a novel matrix for rapid quantitative and qualitative determination of serum free fatty acids by matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry.
abstract: The blood free fatty acids (FFAs), which provide energy to the cell and act as substrates in the synthesis of fats, lipoproteins, liposaccharides, and eicosanoids, involve in a number of important physiological processes. In the present study, matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS) with ammonia-treated N-(1-naphthyl) ethylenediamine dihydrochloride (ATNEDC) as a novel MALDI matrix in a negative ion mode was employed to directly quantify serum FFAs. Multiple point internal standard calibration curves between the concentration ratios of individual fatty acids to internal standard (IS, C17:0) versus their corresponding intensity ratios were constructed for C14:0, C16:1, C16:0, C18:0, C18:1, C18:2, C18:3, C20:4, and C22:6, respectively, in their mixture, with correlation coefficients between 0.991 and 0.999 and limits of detection (LODs) between 0.2 and 5.4μM, along with the linear dynamic range of more than two orders of magnitude. The results indicate that the multiple point internal standard calibration could reduce the impact of ion suppression and improve quantification accuracy in the MALDI mode. The quantitative results of nine FFAs from 339 serum samples, including 161 healthy controls, 118 patients with hyperglycemia and 60 patients without hyperglycemia show that FFAs levels in hyperglycemic patient sera are significantly higher than those in healthy controls and patients without hyperglycemia, and elevated FFA levels are also associated with increased levels of fasting blood glucose (FBG) in hyperglycemic patient sera. Serum FFAs were identified on the basis of the observed accurate molecular masses and reliable isotope distributions obtained by MALDI-FTICR MS.
authors: Department of Biophysics and Structural Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, 5 Dongdan San Tiao, Beijing 100005, PR China.
authors: Yaping
authors: Y
authors: Zhang
authors: Yanmin
authors: Y
authors: Wang
authors: Shuai
authors: S
authors: Guo
authors: Yumei
authors: Y
authors: Guo
authors: Hui
authors: H
authors: Liu
authors: Zhili
authors: Z
authors: Li
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D005029:Ethylenediamines / Q000737:chemistry*; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005583:Fourier Analysis; D006801:Humans; D057230:Limit of Detection; D013058:Mass Spectrometry; D015203:Reproducibility of Results; D013048:Specimen Handling; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
chemical_list: D005029:Ethylenediamines; D005230:Fatty Acids, Nonesterified; C008588:N-(1-naphthyl)ethylenediamine; D000641:Ammonia
keywords: ATNEDC; Ammonia-treated N-(1-naphthyl) ethylenediamine dihydrochloride; FA; FBG; FFA; Free fatty acids; Hyperglycemia; IS; LOD; MALDI-FTICR MS; Matrix-assisted laser desorption ionization-Fourier-transform ion cyclotron resonance mass spectrometry; RSD; Serum; ammonia-treated N-(1-naphthyl) ethylenediamine dihydrochloride; fasting blood glucose; fatty acid; free fatty acid; internal standard; limit of detection; matrix-assisted laser desorption ionization-Fourier-transform ion cyclotron resonance mass spectrometry; relative standard deviation