Analytical Measuring Techniques

Optical: Spectrophotometry

Optical activity is the ability of a chiral substance to rotate the plane of polarized light. Is measured using a device called a polarimeter. The optical rotation or optical activity is the rotation of the linear polarization of light as it travels through certain materials. Usually a phenomenon that occurs in solutions molecules present chiral such as sucrose (sugar), solid crystalline planes rotated, such as quartz, and the circular polarization of atomic or molecular gases. It is used in the processing industry of sugar to measure the syrup concentration of sugars in optics to manipulate polarization, in chemistry to characterize substances in aqueous solution, and medicine is currently being evaluated as a method of determining the concentration of blood sugar in cases of people suffering from diabetes. The optical activity is the property that has a chiral structure to interact with electromagnetic radiation. It is manifested by the existence of the optical rotation, the phenomenon of optical dispersion (ORD), the circular dichroism (CD) and circularly polarized emission.

Spectrophotometry is the method most widely used optical analysis in biological research. The spectrophotometer is an instrument for comparing the radiation absorbed or transmitted by a solution containing an unknown amount of solute, and one containing a known amount of the same substance. All substances can absorb radiant energy, although the glass that appears to be completely transparent absorbs wavelengths belonging to the visible spectrum, the water absorbs strongly in the infrared region. The absorption of ultraviolet radiation, visible and infrared depends on the structure of molecules, and is characteristic for each chemical. Spectrophotometry is a quantitative chemical analysis method based on measuring the absorbance of a colored solution and the use of a calibration curve. The main applications are: Determining the amount of concentration in a solution of a compound using the formulas, the determination of molecular structures and the identification of specific structural units since these have different types of absorbance (functional groups or isomorphic).

Electrochemistry: ISE

Electrochemical is a branch of chemistry that studies transformation of electrical energy and chemical energy. In other words, the chemical reactions that occur at the interface of an electrical conductor (called electrode, which may be a metal or a semiconductor) and an ionic conductor (the electrolyte) may be a solution in some special cases, a solid. In general, the electrochemistry is required to examine situations where there are reactions of oxidation and reduction was found ...