Sensitivity enhancement methods description

The identification of individual classes of fatty acids has relied on the use of gas chromatography (GC), equipped with a flame ionization detector. Lipids are sapoiufled after extraction and the fatty acids converted to methyl esters. The fatty acid methyl esters (FAME) are separated using GC. The use of standards ahowed for the identification of individual species of fatty acids based on retention time. The method is quite sensitive and permits the quantification of fatty acid species. The mode of detection has been enhanced with the use of mass spectrometry (MS), which allows for the detection and quantification of unknowns, thus increasing the utility of these methods. The Lipid Library section on the gas chromatography of lipids http //www.lipidlibrary.co.uk/GCJipid/01 intro/index. htm) provides a comprehensive description of these methods. 

The introduction of in-situ infrared spectroscopy to electrochemistry has revolutionised the study of metal/electrolyte interfaces. Modnlation or sampling techniques are applied in order to enhance sensitivity and to separate snrface species from volume species. Methods such as EMIRS (electrochemicaUy modulated IR spectroscopy) and SNIFTIRS (subtractively normalised interfacial Fonrier Transform infrared spectroscopy) have been employed to study electrocatalytic electrodes, for example. There have been surprisingly few studies of the semiconductor/electrolyte interface by infrared spectroscopy. This because up to now little emphasis has been placed on the molecnlar electrochemistry of electrode reactions at semiconductors because the description of charge transfer at semiconductor/electrolyte interfaces is derived from solid-state physics. However, the evident need to identify the chemical identity of snrface species should lead to an increase in the application of in-situ FTIR. 

This monograph is truly unprecedented in its scope, both in terms of content and the breadth of the collective expertise. Its editors, Claudia Ruiz-Capillas and Leo M.L. Nollet, assembled a team of 80 authors from 14 countries to compose a work in 36 chapters of which the first six deal with FIA techniques, while the body of the work is focused on the ways in which a wide variety of samples and analytes can be assayed. The methods listed include preservatives, antioxidants, sweeteners, colorants, flavor enhancers, and other species. And this is where the lasting value of this exceptional book is to be found—in the detailed description of the amazing variety of underlying chemistries on which the individual assay protocols are based. As flow-based methodology and instrumentation evolve, their older versions are becoming obsolete however, the chemistry of the underlying chemical reactions will remain the cornerstone on which the selective and sensitive assay protocols are based. 

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