1. Definition of Analytical Chemistry
Analytical Chemistry is a science in which people obtain information about the chemical composition and structure of substances.
2. The tasks of analytical chemistry
1. Qualitative analysis ── To identify the chemical composition (or composition) of substances, such as elements, ions, atomic groups, compounds, etc., that is, to “solve the problem of what a substance is”.
2. Quantitative analysis ── Determining the content of the relevant components in the substance, that is, “solving the problem of how much the substance is”.
3. Structural analysis ── Determining the chemical structure of a substance, such as molecular structure, crystal structure, etc.
3. Classification of Analytical Chemistry
Classification by analysis principle: chemical analysis and instrumental analysis
Chemical analysis ── The analysis method based on the chemical reaction of substances, also known as classical analysis method. Includes gravimetric and volumetric analysis (titration analysis).
Features: simple instrument, accurate results, low sensitivity, slow analysis speed.
Instrumental Analysis — Analytical methods based on the physical and physicochemical properties of substances. Including electrochemical analysis, Chromatography, Spectroscopy, Spectrum Analysis, Mass Spectrometry, thermal analysis, radiochemical analysis, etc.
Features: sensitive, fast and accurate.
4. The role of analytical chemistry
The scope of application of analytical chemistry involves almost all aspects of national economy, national defense construction, resource development, and people’s basic necessities of life. It can be said that the so-called “four major theories” in the field of contemporary science (the origin and evolution of celestial bodies, earth, life, and human beings) and the “five major crises” (resources, energy, population, food, and environment) facing human society, the problems The solutions are closely related to the research of the basic discipline of analytical chemistry.
① The importance of analytical chemistry in scientific research
At present, environmental pollution such as air, rivers, oceans and soils worldwide is destroying the normal ecological balance, and even endangering the development and survival of human beings. In order to track pollution sources, clarify the types and quantities of pollutants, and study their transformation rules and degree of harm Analytical chemistry plays an extremely important role;
In the research of new materials, the characterization and determination of the content, form and spatial distribution of trace impurities have become the key to the development of high-tech and microelectronics industries;
In resource and energy science, analytical chemistry is the main means to obtain geological mineral composition, structure and performance information and reveal the geological environment change process. The detection, mining and refining of coal, oil, natural gas and nuclear material resources are even more important. Inseparable from the analysis and testing work;
Analytical chemistry is of great significance in the study of life process chemistry, bioengineering, and biomedicine in revealing the origin of life, life processes, diseases, and genetic mysteries.
In medical science, pharmaceutical analysis is an indispensable means in the research of drug content, drug mechanism of action, drug metabolism and decomposition, pharmacokinetics, disease diagnosis, and drug abuse.
In space science research, the analysis of interstellar matter has become the most important means to understand and examine the composition of matter in the universe and its transformation.
② The importance of analytical chemistry in industrial and agricultural production and national defense construction
The importance of analytical chemistry in industrial production is mainly manifested in product quality inspection, process control and commodity inspection;
In terms of agricultural production, analytical chemistry plays an important role in traditional agricultural production, in the survey of water and soil components, pesticides, fertilizers, residues and quality inspection of agricultural products. In the transformation of the “green revolution” based on bioengineering, analytical chemistry will also play an important role in the research of cell engineering, genetic engineering, fermentation engineering and protein engineering;
In national defense construction, analytical chemistry is widely used in the research of chemical warfare agents, weapon structural materials, aerospace, navigation materials, power materials and environmental atmosphere;
5. Overview of the development of analytical chemistry
The origin can be traced back to ancient alchemy. In the history of science, analytical chemistry was once a pioneer in the study of chemistry. It made important contributions to the discovery of elements and the determination of atomic weight. However, until the end of the 19th century, people still believed that analytical chemistry was still Without an independent theoretical system, it can only be regarded as an analytical technique, not a science.
Since the 20th century, analytical chemistry has experienced three great changes.