Improved fatty acid detection in micro-algae and aquatic meiofauna species using a direct thermal desorption interface combined with comprehensive gas chromatography-time-of-flight mass spectrometry.
Comprehensive two-dimensional gas chromatography (GC x GC) with time-of-flight mass spectrometry detection is used to profile the fatty acid composition of whole/intact aquatic microorganisms such as the common fresh water green algae Scenedesmus acutus and the filamentous cyanobacterium Limnothrix sp. strain MRI without any sample preparation steps. It is shown that the technique can be useful in the identification of lipid markers in food-web as well as environmental studies. For instance, new mono- and diunsaturated fatty acids were found in the C(16) and C(18) regions of the green algae S. acutus and the filamentous cyanobacterium Limnothrix sp. strain MRI samples. These fatty acids have not, to our knowledge, been detected in the conventional one-dimensional (1D) GC analysis of these species due to either co-elution and/or their presence in low amounts in the sample matrix. In GC x GC, all congeners of the fatty acids in these microorganisms could be detected and identified due to the increased analyte detectability and ordered structures in the two-dimensional separation space. The combination of direct thermal desorption (DTD)-GC x GC-time-of-flight mass spectrometry (ToF-MS) promises to be an excellent tool for a more accurate profiling of biological samples and can therefore be very useful in lipid biomarker research as well as food-web and ecological studies.
Akoto
Lawrence
L
Vrije Universiteit, Department of Analytical Chemistry and Applied Spectroscopy, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands. l.akoto@few.vu.nl
Stellaard
Frans
F
Irth
Hubertus
H
Vreuls
René J J
RJ
Pel
Roel
R
D002244:Carbon; D000460:Chlorophyta / Q000737:chemistry*; D000458:Cyanobacteria / Q000737:chemistry*; D005227:Fatty Acids / Q000032:analysis* / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D012015:Reference Standards; D013696:Temperature
D005227:Fatty Acids; D002244:Carbon