Recent Advances in Techniques

SBSE appears to be particularly useful for the extraction of a variety of components from beverages and sauces. Applications have included coffee [144], soft drinks [150], orange juice [147], lemon-flavored beverages [146], wine [147,149,150], balsamic vinegar [150], and soy sauce [150], 

SBSE was recently applied [152] to the analysis of off-flavor compounds, including 2-methylisoborneol (2-MIB) and geosmin, in drinking water. These organic compounds cause taste and odor problems at very low concentrations and are notoriously difficult to extract. Detection limits by SBSE ranged from 0.022 to 0.16 ng/L. The recoveries ranged from 89 to 109% with relative standard deviations of 0.80 to 3.7%. 

Yercauteren et al. [145] used SBSE to determine traces of organotin compounds in environmental samples at part per quadrillion (ppq) levels. The limits of detection reported using SBSE are the lowest ever determined for these compounds. 

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B. Recent Advances in Technique 1. Photoionization cross-section measurement... 

While discussing this subject, it is of interest to note that a recent advance in technique has been to obtain spectra when only one layer of material is adsorbed at a coverage of unity. Francis and Ellison (146) have obtained spectra of layers of metal stearates adsorbed on mirrors, and Pickering and Eckstrom (146a) have studied low molecular weight gases (such as H2 and CO) chemisorbed on metal mirrors. 

Recent advances in techniques for the determination of the structures of oligosaccharides by high-resolution mass spectroscopy make it likely that the classic chemical techniques discussed above may be largely replaced by mass spectroscopy. When sufficient quantities of an oligosaccharide of unknown structure are available, nuclear magnetic resonance (NMR) spectroscopy provides another valuable tool for structure analysis. 

However, recent advances in techniques will ensure further diversification and complexification of solved surface structures. The present maturity of techniques will thus increasingly allow the analysis of structures chosen for their practical interest rather than for their simplicity. 

Shown in Scheme 13 are some of the stoichiometric intramolecular aminations so far reportedJ The application of recent advances in techniques may enhance the synthetic utility of these reactions by making them catalytic. 

Gal, S., Recent advances in techniques for the determination of sorption isothers, in Water Relations of Foods, R.B. Duckworth (Ed.), Academic Press, London, 1975, pp. 139-154. 

Recent advances in techniques used, in particular availability of high-resolution transmission electron microscopes, as well as interpreting and processing the images, have allowed resolutions of the order of atomic structures in inorganic crystal (below 0.1 nm). However, the best resolution achieved in polymers is, in practice, poorer than this because of polymer-specific problems with high electron irradiation sensitivity and low contrast. 

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