Quantitation headspace

A. J. Matich, D. D. Rowan, N. H. Banks, Solid phase microextraction for quantitative headspace sampling of apple volatiles, Anal. Chem., 68, 4114 4118 (1996). 

B. Kolb, Multiple headspace extraction — a procedure for eliminating the influence of the sample matrix in quantitative headspace gas chromatography, Chromatographia, 75 587-594(1982). 

Hence, the standard additions method is unique in that it actually employs the very material under analysis as a reference matrix material, thus providing for efficient elimination of very complex matrix effects even when the final material is the result of a multi-step preparative procedure and the composition of the matrix of the original material is completely unknown. These advantageous features of the standard additions technique have been discussed and verified in context with quantitative headspace gas analysis [68]. 

Zehentbauer, G., Grosch, W. (1997) Apparatus for quantitative headspace analysis of the characteristic odorants of baguettes. Z. Lebensm. Unters. Forsch. 205 262-267... 

For quantitative headspace gas analysis, parameters affecting the equilibrium in the system as well as the sample matrix must be taken into consideration. Theoretical aspects of the thermodynamic equilibrium have been studied by different authors [85-88]. The distribution constant of the solute in the gas-liquid-phase system can be defined as the ratio of the concentration in the liquid phase (Cl) to that in the gaseous phase (Cg) [54] ... 

Bruno, T. J., Simple, Quantitative Headspace Analysis by Cryoadsorption on a Short Alumina PLOT Column, J. Chromatogr. Sci. 47,1,2009. 

PA Rodriguez, CR Culbertson. Quantitative headspace analysis of selected compounds in equilibrium with orange juice. In G Charalambous, G Inglett, eds. Instrumental Analysis of Foods, Vol. 2. New York Academic Press, 1983, pp 187-195. 

The principle of headspace sampling is introduced in this experiment using a mixture of methanol, chloroform, 1,2-dichloroethane, 1,1,1-trichloroethane, benzene, toluene, and p-xylene. Directions are given for evaluating the distribution coefficient for the partitioning of a volatile species between the liquid and vapor phase and for its quantitative analysis in the liquid phase. Both packed (OV-101) and capillary (5% phenyl silicone) columns were used. The GG is equipped with a flame ionization detector. 

Lu, G. et al.. Quantitative determination of geosmin in red beets (Beta vulgaris L.) using headspace solid-phase microextraction, J. Agric. Food Chem., 51, 1021, 2003. 

The headspace volatiles from biological fluids are comprised of a chemically diverse group of substances of widely different polarity most are alcohols, ketones, aldehydes, O- and M-hetrocyclic cosqpounds, isocyanates, sulfides, and hydrocarbons containing from 1 to 12 carbon atoms and with boiling points generally less than 300 C [342]. Quantitative differences in... 

Small solid seuaples can be analyzed directly by dynamic headspace sampling using a platinum coil and quartz crucible pyrolyzer and cold trap coupled to an open tubular column (341,369,379). This method has been used primarily for the analysis of mineral samples and of additives, catalysts and byproducts in finished polymers which yield unreliable results using conventional headspace techniques owing to the slow release of the volatiles to the headspace. At the higher temperatures (450-1000 C) available with the pyrolyzer the volatiles are more readily and completely removed from the sample providing for quantitative analysis. 

Dynamic headspace GC-MS involves heating a small amount of the solid polymer sample contained in a fused silica tube in a stream of inert gas. The volatile components evolved on heating the sample are swept away from the sample bulk and condensed, or focused on a cryogenic trap before being introduced onto the chromatographic column via rapid heating of the trap. The technique can be used qualitatively or quantitatively DHS-GC-MS is considered to be well suited towards routine quantitative analysis. 

D. Zabaras, S. G. Wyllie, Quantitative analysis of terpenoids in the gas phase using headspace solid phase microextraction (HS SPME), Flavour Fragr. J., 16, 411 416 (2001). 

J. Ai, Headspace solid phase microextraction. Dynamics and quantitative analysis before reaching a partition equilibrium, Anal. Chem., 69, 3260 (1997). 

In general, zero-headspace procedures are employed when the concentrations of volatiles in the soil are relatively low, and solvent extraction methods are used for more polluted soils. Irrespective of which procedure is used, quantitation of volatiles in soil is subject to serious errors if sufficient care is not taken with the sampling operation. Although direct purge-and-trap methods are frequently advocated for the determination of volatiles in samples collected by zero-headspace procedures, there are certain problems associated with this technique. Caution is advised since the procedure really collects only that fraction of the volatile that exists in a free form within the soil pore spaces or is at least in a facile equilibrium with this fraction. 

Although a variety of methods are available for determination of 1,4-dichlorobenzene in blood, few are well characterized and validated. A method has been developed which utilizes headspace purge followed by thermal desorption of the trapped, purged analytes. 1,4-Dichlorobenzene is then determined by capillary GC/MS (Michael et al. 1980 Pellizzari et al. 1985). Recovery is very good (>85%) and detection limits are in the low-ppb range for model compounds (Michael et al. 1980 Pellizzari et al. 1985). Performance data are not available for 1,4-dichlorobenzene. A sensitive and reliable method for identification and quantitation of 1,4-dichlorobenzene in samples of whole blood has been developed by Ashley and coworkers at the Centers for Disease Control and Prevention (CDC) (Ashley et al. 1992). 

Herzfeld D, van der Gun K, Louw R. 1988. Quantitative determination of volatile organochlorine compounds in water by GC-headspace analysis with dibromomethane as an internal standard. Chemosphere 1425-1430. 

---