Attempts to Detect Lipid Metabolites from a Single Cell Using Proton-Transfer-Reaction Mass Spectrometry Coupled with Micro-Scale Supercritical Fluid Extraction: A Preliminary Study

Abstract

Proton-transfer-reaction (PTR) mass spectrometry (MS), a widely used method for detecting tracelevels of volatile organic compounds in gaseous samples, can also be used for the analysis of small nonvolatile molecules by using supercritical fluid as a transporter for the molecules. Supercritical fluid extraction (SFE) is a method that permits lipophilic compounds to be rapidly and selectively extracted from complex matrices. The combination of the high sensitivity of PTR MS with the SFE is a potentially novel method for analyzing small molecules in a single cell, particularly for the analysis of lipophilic compounds. We preliminarily evaluated this method for analyzing the components of a single HeLa cell that is fixed on a stainless steel frit and is then directly introduces the SFE extracts into the PTR MS. A total of 200/90 ions were observed in positive/negative ion mode time-of-flight mass spectra, and the masses of 11/10 ions could be matched to chemical formulae obtained from the LipidMaps

A Method for High Throughput Free Fatty Acids Determination in a Small Section of Bovine Liver Tissue Using Supercritical Fluid Extraction Combined with Supercritical Fluid Chromatography-Medium Vacuum Chemical Ionization Mass Spectrometry

“…We have been studying SFE coupled with SFC with MVCI MS to determine amounts of lipophilic metabolite in a cell or a small piece of tissue. 7 , 8) The accuracy of quantitative analysis using chromatography depends on several factors, such as column efficiency, peak resolution between coeluted molecules, and ionization efficiency. Another critical consideration relates to distinguishing an assigned molecule, discerning whether it originated from a cellular component or arose as a contaminant during the sample processing steps.…”