Premium
Improved analysis of ladderane lipids in biomass and sediments using high‐performance liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry
Author(s) -
Hopmans Ellen C.,
Kienhuis Michiel V. M.,
Rattray Jayne E.,
Jaeschke Andrea,
Schouten Stefan,
Damsté Jaap S. Sinninghe
Publication year - 2006
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.2572
Subject(s) - chemistry , mass spectrometry , atmospheric pressure chemical ionization , chemical ionization , chromatography , atmospheric pressure , high performance liquid chromatography , ionization , analytical chemistry (journal) , ion , organic chemistry , oceanography , geology
Ladderane lipids, containing three or five linearly concatenated cyclobutane moieties, are considered to be unique biomarkers for the process of anaerobic ammonium oxidation, an important link in the oceanic nitrogen cycle. Due to the thermal lability of the strained cyclobutane moieties, the ladderane lipids are difficult to analyze by gas chromatography. A method combining high‐performance liquid chromatography coupled to positive ion atmospheric pressure chemical ionization tandem mass spectrometry (HPLC/APCI‐MS/MS) was developed for the analysis of the most abundant ladderane lipids, occurring as fatty acids and ether‐bound to glycerol. Detection was achieved by selective reaction monitoring of four specific fragmentations per ladderane lipid. Detection limits of 30–35 pg injected on‐column and a linear response (r 2 > 0.99) over nearly 3 orders of magnitude were achieved for all compounds. Using this method, these unique ladderane lipids were for the first time identified in a surface sediment from the Gullmarsfjorden, in concentrations ranging from 1.1–5.5 ng/g for the ladderane fatty acids and of 0.7 ng/g for the monoether. It is foreseen that this method will allow the investigation of the occurrence of anaerobic ammonium oxidation in natural settings in much greater detail than before. Copyright © 2006 John Wiley & Sons, Ltd.