title: Microquantification of phospholipid classes by stable isotope dilution and nanoESI mass spectrometry.
abstract: A new method for microquantification of phospholipid classes by nanoelectrospray mass spectrometry and stable isotope dilution is presented. The method covers the sum of phosphatidylcholine and sphingomyelin and in addition selectively quantifies phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol. A phospholipid class is quantified together with its corresponding lyso-species due to the presence of a common head group. Phospholipids are extracted from tissue lysates, hydrolysed by hydrofluoric acid, and the liberated polar head groups choline, ethanolamine, serine, and inositol are quantified by nanoelectrospray mass spectrometry using deuterium-labeled analogs of the head groups as internal standards. The method is applied to tissue samples of a gastrointestinal tumor and of corresponding non-affected control tissue. In the tumor sample, the abovementioned phospholipids were found at roughly threefold elevated concentrations with a virtually unaltered relative abundance profile.
authors: Molecular Structure Analysis, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.|Faculty of Applied Science, Universiti Teknologi Mara, 40450, Shah Alam, Selangor, Malaysia.
authors: Muhd Fauzi
authors: MF
authors: Safian
authors: Molecular Structure Analysis, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.|Cellzome GmbH, EMBL Campus, Meyerhofstr. 1, 69117, Heidelberg, Germany.
authors: Nico
authors: N
authors: Zinn
authors: Molecular Structure Analysis, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.|Novartis AG, Schaffhauserstrasse, 4332, Stein, Switzerland.
authors: Joerg
authors: J
authors: Seidler
authors: Molecular Structure Analysis, German Cancer Research Center, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany. w.d.lehmann@alumni.uni-heidelberg.de.
authors: Wolf D
authors: WD
authors: Lehmann
keywords: Hydrofluoric acid; Nanoelectrospray; Phosphatidylcholine; Phosphatidylethanolamine; Phosphatidylinositol; Phosphatidylserine; Stable isotopes