Determination of organic compounds from wood combustion aerosol nanoparticles by different gas chromatographic systems and by aerosol mass spectrometry

Selection of Analytical Methodology for Metabolomics

The main challenge in metabolomics analysis is the separation, identification and quantification of a large number of known or unknown metabolites in complex samples. The correct selection of sample collection and preparation method, type of separation methodology and detection are all crucial steps in the analysis of metabolomics. This chapter provides an overview of and general guidelines for strategies involved in the analysis of metabolomics, and different chromatographic techniques used in metabolomics studies are briefly presented. The methods are compared and the main features of the separation methods are listed. Finally, general conclusions and future perspectives are provided.

Development and validation of a comprehensive two-dimensional gas chromatography-mass spectrometry method for the analysis of phytosterol oxidation products in human plasma

Phytosterol oxidation products (POPs) have been suggested to exert adverse biological effects similar to, although less severe than, their cholesterol counterparts. For that reason, their analysis in human plasma is highly relevant. Comprehensive two-dimensional gas chromatography (GC×GC) coupled with time-of-flight mass spectrometry (TOF-MS) has been proven to be an extremely powerful separation technique for the analysis of very low levels of target compounds in complex mixtures including human plasma. Thus, a GC×GC/TOF-MS method was developed and successfully validated for the simultaneous quantification of ten POPs in human plasma. The calibration curves for each compound showed correlation coefficients (R(2)) better than 0.99. The detection limits were below 0.1 ng mL(-1). The recovery data were between 71.0% and 98.6% (RSDs <10% for all compounds validated). Good results were obtained for within- and between-day repeatability, with most values being below 10%. In addition, non-targeted sterol metabolites were also identified with the method. The concentrations of POPs found in human plasma in the current study are between 0.3 and 4.5 ng mL(-1), i.e., 10-100 times lower than the typical values found for cholesterol oxidation products.