Spectroscopy And Chromatography Technology Replaces Winetasting
In San Francisco a winemaker is using analytical chemistry to supplement the technique of winetasting. Winetasting is a time-honored practice of tasting a mouthful of grapes to determine when the fruit is ready for picking. Now spectroscopy and chromatography replaces this technique. This new technique evaluates the aroma, color and taste of grapes. Grapes can be analysed for their molecular makeup. Molecules indicative of aroma, taste and feel can be identified in this method and the grapes are then harvested.
Spectroscopy, in physics and physical chemistry, the study of spectra (see Spectrum). The basis of spectroscopy is that each chemical element has its own characteristic spectrum (see Elements, Chemical). This fact was recognized in 1859 by the German scientists Gustav Robert Kirchhoff and Robert Wilhelm Bunsen. They developed the prism spectroscope in its modern form and applied it to chemical analysis. One of two principal spectroscope types, this instrument consists of a slit for admitting light from an external source, a group of lenses, a prism, and an eyepiece. Light that is to be analyzed passes through a collimating lens, which makes the light rays parallel, and the prism; then the image of the slit is focused at the eyepiece. One actually sees a series of images of the slit, each a different color, because the light has been separated into its component colors by the prism. The German scientists were the first to recognize that characteristic colors of light, or the spectra, are emitted and absorbed by particular elements.
Chromatography, in chemistry, analytical technique used for the chemical separation of mixtures and substances. The technique depends on the principle of selective adsorption (not to be confused with absorption), a type of adhesion. Chromatography was discovered in 1906 by the Italian-born Russian botanist Mikhail Tswett, but was not widely used until the 1930s. Tswett separated plant pigments (chlorophylls) by pouring petroleum-ether extract of green leaves over a column of powdered calcium carbonate in a vertical glass tube. As the solution percolated through the column the individual components of the mixture migrated downward at different rates of speed, so that the column became marked with horizontal bands of colors, called a chromatogram. Each band corresponded to a different pigment.
Analytical Chemistry, one of the major branches of modern chemistry. It is subdivided into two main areas, qualitative and quantitative analysis. The former involves the determination of unknown constituents of a substance, and the latter concerns the determination of the relative amounts of such constituents.
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