Microcrystalloscopy

Microcrystalloscopy is a method of qualitative microchemical analysis based on the formation of characteristic crystalline precipitates under the action of small amounts of reagents per drop (about 10 ⁻³ ml) of the analyzed solution on a glass slide. The sediment is examined under a microscope (an increase of 60 or more times); its composition is judged mainly by the shape of the crystals, as well as by their color and size. The resulting crystals acquire a characteristic shape only upon slow release, that is, in dilute solutions. At high concentrations of the deposited substances, as well as in the presence of foreign compounds, crystal shape distortion is possible. In such cases, crystallographic and crystal-optical characteristics of crystals (for example, angles between faces) are determined under a polarizing microscope to identify the precipitate, depending not on their shape, but on the chemical composition. Microcrystalloscopy is usually used to analyze very small objects (plant cells, inclusions in metals, minerals, and so on). The detection limit of organic and inorganic compounds reaches 10 ⁻⁸ −10 ⁻⁹ g in a drop of solution.