Analytical chemistry is a long story that needs to be explained from different fields:
Analytical chemistry is an important branch of chemistry, which mainly studies what elements or chemical groups are in a substance (qualitative analysis); how is the quantity or material purity of each component (quantitative analysis); how atoms are connected into molecules, how they are arranged in space, and so on.
Analytical chemistry is based on the basic theory of chemistry and experimental techniques, and absorbs knowledge of physics, biology, statistics, electronic computers, automation, etc. to enrich its content, so as to solve various analytical problems raised by science and technology.
Although the name Analytical Chemistry was coined by Boyle, its practical application is as old as the chemical process. The high development of ancient smelting, brewing and other techniques are closely related to means of identification, analysis, and control of the production process. The alchemy and alchemy that emerged in the East and West can be regarded as the precursors of analytical chemistry.
In 3000 BC, the Egyptians had mastered some weighing techniques. The earliest analytical instrument was the equiarm balance, which was recorded in the “Papyrus Scroll” in 1300 BC. Stone standard weights (c. 2600 BC) kept by the priests of Babylon survive. However, the use of equilibrated balances in chemical analysis began in the medieval roasting bowl assay.
Among the elements recognized in ancient times, non-metals include carbon and sulfur, and metals include copper, silver, gold, iron, lead, tin, and mercury. In the 4th century BC, touchstones were used to identify the fineness of gold. In the 3rd century BC, Archimedes used the difference in density between gold and silver when he solved the problem of the purity of the gold crown of King Xilang II of Syracuse. A pioneer in non-destructive analysis.
Around 60 A.D., Pliny the Elder applied the Galla gall extract on papyrus to detect iron, an adulterant of copper sulfate. This was the earliest organic reagent used and also the earliest test paper. As late as 1751, Erler von Brockhausen used the same method to detect the iron content in blood residue (after ashing).
The fire assay is an ancient analytical method. As far back as the 13th century BC, the King of Babylon wrote to Pharaoh Amenphis IV of Egypt, saying: “After the golden scriptures sent by your majesty were put into the furnace, their weight decreased…” This shows that more than 3,000 years ago, people knew the fact that “real gold is not afraid of fire”. Philip VI of France once stipulated the steps of gold inspection, which put forward the structural requirements and usage methods of the balance used, such as the balance should not be placed in a place exposed to wind or cold, and the user’s breath should not affect the weighing of the balance.
The Swedish chemist Bergman in the 18th century can be called the founder of inorganic qualitative and quantitative analysis. He was the first to propose that metal elements can be separated and weighed in other forms besides the metal state, especially in the insoluble form in water, which is the origin of the wet method in gravimetric analysis.
German chemist Klaproth not only improved the steps of gravimetric analysis, but also designed a variety of non-metal element determination steps. He accurately determined the composition of nearly 200 kinds of minerals and various industrial products such as glass and non-ferrous alloys.
The representative figure of analytical chemistry in the 18th century first recommended Berzelius. He introduced some new reagents and some new tricks and used ashless filter paper, low ash filter paper and wash bottles. He was the first chemist to measure atomic weights more accurately. In addition to inorganic substances, he also determined the percentage of elements in organic substances. He was the first chemist to measure atomic weights more accurately. In addition to inorganic substances, he also determined the percentage of elements in organic substances. This method has been used until the 19th century, and its advantages are that it is fast, requires a small amount of samples, and can be used for field exploration and general survey of mineral resources.
One of the luminaries of analytical chemistry in the 19th century was Frasenius, who founded a specialized school of analytical chemistry (which still exists today); In 1862, he founded the German “Analytical Chemistry” magazine, and his descendants continue to serve as editor-in-chief until now. The two books “Qualitative Analysis” and “Quantitative Analysis” written by him have been translated into many languages.
In 1663, Boyle reported the use of plant pigments as acid-base indicators, which was a pioneer in capacity analysis. But the real capacity analysis is due to Guy Lussac of France. In 1824, he published the determination of available chlorine in bleaching powder, using sulfonated indigo as indicator. He then titrated plant ash with sulfuric acid and silver nitrate with sodium chloride. These three works represent redox titration, acid-base titration, and precipitation titration, respectively. Complexometric titration was invented by Liebig for the titration of cyanide ions with silver.
Another person who made an outstanding contribution to volumetric analysis was Mohr of Germany. The burette designed by him to hold a strong alkali solution is still in use today. He recommended oxalic acid as the reference substance for the alkalimetric method, and ammonium ferrous sulfate (also known as Mohr’s salt) as the reference substance for the redox titration method.