专业英语-week 13.ppt

Introduction to Analytical Chemistry Chemistry is the study of matter, including its composition, structure, physical properties, and reactivity. There are many approaches to studying chemistry, but, for convenience, we traditionally divide it into five fields: organic, inorganic, physical, biochemical, and analytical. Analytical chemistry is often described as the area of chemistry responsible for characterizing the composition of matter, both qualitatively (what is present) and quantitatively (how much is present). This description is misleading. In recent years, research in analytical chemistry has concerned mainly on the development and application of physical and physicochemical analytical methods, instrumental analysis, which in their speed and sensitivity have far surpassed the classic methods of gravimetric, and even volumetric analysis. Now in analysis the final detection is carried out almost instrumentally. Students have to learn many informations about instrumental analysis. But in the case of analyzing real samples the most important problem is how to treat them before the instrumental measurement, that is, decomposition of sample, separation from matrix, preconcentration etc. Instrumental analysis is based on to compare the signal from the sample with that from standard. Recently standard solutions for instrumental analysis are easy to get on the market. But in the basic education in analytical chemistry it is important to teach how to get the accurate amount of a particular substance in a sample absolutely by weighing the precipitation or measuring the volume of the solution. We would like to emphasize that the basic education in analytical chemistry for future generations of chemists is to teach how to get the accurate analytical data. For this purpose the desirable curriculum of analytical chemistry is considered to be composed of chemical analysis, separation chemistry and instrumental analysis, including experiments to learn the analytica