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Rapid analysis of intact phospholipids from whole bacterial cells by matrix‐assisted laser desorption/ionization mass spectrometry combined with on‐probe sample pretreatment
Author(s) -
Ishida Yasuyuki,
Madonna Angelo J.,
Rees Jon C.,
Meetani Mohammed A.,
Voorhees Kent J.
Publication year - 2002
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.802
Subject(s) - chemistry , mass spectrometry , chromatography , matrix assisted laser desorption/ionization , analytical chemistry (journal) , trifluoroacetic acid , sample preparation , mass spectrum , matrix (chemical analysis) , aqueous solution , desorption , organic chemistry , adsorption
Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS), utilizing an on‐probe sample pretreatment, was applied to the rapid and direct detection of intact phospholipids from whole bacterial cells. The sample preparation procedure involved depositing growing bacterial colonies from culture dishes directly onto the MALDI probe followed by treatment of the sample spot with a 3 µL aliquot of an aqueous 0.05 M solution of sodium iodide prior to the addition of a 2,5‐dihydroxybenzoic acid (DHB) matrix solution (ca. 8 mg dissolved in 70% acetonitrile/30% H 2 O containing 0.1% of trifluoroacetic acid). The MALDI spectra obtained from whole bacteria cells showed a series of ions generated from bacterial phospholipids, such as phosphatidylethanol‐amines (PEs) and phosphatidylglycerols (PGs), which were clearly observed as well‐resolved peaks. The ranges of the observed total carbon numbers in two acyl groups for PEs and PGs (30–36 and 33–36, respectively) were in good agreement with those reported previously. Furthermore, the distinct discrimination of four species of the Enterobacteriaceae family cultured identically was achieved by using principal components analysis (PCA) conducted on the relative peak intensities of phospholipids observed from the MALDI spectra. Copyright © 2002 John Wiley & Sons, Ltd.