Some aspects of high-resolution gas chromatographic analysis of complex volatile samples

Analysis of volatile mouse pheromones by gas chromatography mass spectrometry

High-precision quantitative profiling of volatile organic constituents in rodent physiological fluids and glandular secretions is needed to relate olfactory signals to physiology and behavior. Whereas capillary gas chromatography-mass spectrometry (GC-MS) analysis has become the most widely applied in such investigations, the extraction and preconcentration of volatile organics is arguably the most critical step in the overall analytical task. In this chapter, we describe technical details of two main sample extraction procedures used in our laboratory: dynamic headspace trapping, and stir bar sorptive extraction (SBSE). They have been demonstrated here for the chromatographic analysis of mouse urine, serum, saliva, and preputial gland specimens.

Biochemical individuality reflected in chromatographic, electrophoretic and mass-spectrometric profiles

This review discusses the current trends in molecular profiling for the emerging systems biology applications. Historically, the methodological developments in separation science were coincident with the availability of new ionization techniques in mass spectrometry. Coupling miniaturized separation techniques with technologically-advanced MS instrumentation and the modern data processing capabilities are at the heart of current platforms for proteomics, glycomics and metabolomics. These are being featured here by the examples from quantitative proteomics, glycan mapping and metabolomic profiling of physiological fluids.

In situ surface sampling of biological objects and preconcentration of their volatiles for chromatographic analysis

This report describes a rolling stir bar sampling procedure for volatile organic compounds (VOCs) present on various biological surfaces. In combination with thermal desorption/gas chromatography/mass spectrometry, this analytical technique was initially tested for quantitative profiling of human skin VOCs. It is also applicable to additional hydrophobic surfaces such as agricultural products, plant materials, and bird feathers. Use of embedded internal standards provides highly reproducible and quantitative results for a wide variety of sampled trace components. The samples of collected human skin VOCs and standards were found stable under cool storage conditions for at least 14 days, making this approach suitable for field biological and agricultural studies. Additionally, this methodology appears to have potential for forensic and toxicological investigations, as suggested through the analyses of VOC profiles of the human thumb prints recovered from a nonbiological smooth surface.

Stir bar sorptive extraction: a new quantitative and comprehensive sampling technique for determination of chemical signal profiles from biological media

Various applications of a novel sampling procedure in chemical ecology are outlined. The stir bar extraction method features the analytical reproducibility needed in recording the analytical profiles of volatile and semivolatile components of biological mixtures. This methodology has been demonstrated here through the examples of small volume urine samples, glandular tissue volatiles, and the air blown through animal cages. Its analytical merits are compared with those of the previously established purge-and-trap (dynamic headspace) technique.

Capillary column gas chromatographic profile analysis of volatile compounds in sera of normal and virus-infected patients

Using a transevaporator sampling technique, the volatile profiles from 70 microliter of serum were obtained by capillary-column gas chromatography. The complex chromatograms were interpreted by a combination of manual and computer techniques and a two-peak ratio method devised for the classification of normal and virus-infected sera. Using the K-nearest neighbor approach 85.7% of the unknown samples were classified correctly. Some preliminary results indicate the possible use of the method for the assessment of virus susceptibility.

A micro method for the determination of volatile metabolites in biological samples. A preliminary report

A new method for analyzing volatile metabolites in biological fluids and tissues has been developed. The procedure involves extraction of the sample with diethyl ether, concentration on a short column of glass wool by elution of the diethyl ether, then thermal desorption of the trace constituents into a chromatographic system. Small samples of 100 mul are quite adequate. The method is applicable to serum, plasma, urine and other fluids. Small tissue samples can also be used with this technique.