Search results
Results from the WOW.Com Content Network
Polyphenols (/ ˌpɒliˈfiːnoʊl, - nɒl /) are a large family of naturally occurring phenols. [ 1 ] They are abundant in plants and structurally diverse. [ 1 ][ 2 ][ 3 ] Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning garments.
Appearance. Microwave digestion is a chemical technique used to decompose sample material into a solution suitable for quantitative elemental analysis via inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectroscopy, or atomic emission spectroscopy (including ICP-AES). It is commonly used in analyses for heavy metals.
Microwave chemistry is the science of applying microwave radiation to chemical reactions. [1][2][3][4][5] Microwaves act as high frequency electric fields and will generally heat any material containing mobile electric charges, such as polar molecules in a solvent or conducting ions in a solid. Polar solvents are heated as their component ...
Fick's first law relates the diffusive flux to the gradient of the concentration. It postulates that the flux goes from regions of high concentration to regions of low concentration, with a magnitude that is proportional to the concentration gradient (spatial derivative), or in simplistic terms the concept that a solute will move from a region of high concentration to a region of low ...
Tannin powder (mixture of compounds) A bottle of tannic acid solution in water. Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids.
Proanthocyanidins are a class of polyphenols found in many plants, such as cranberry, blueberry, and grape seeds. Chemically, they are oligomeric flavonoids. Many are oligomers of catechin and epicatechin and their gallic acid esters. More complex polyphenols, having the same polymeric building block, form the group of condensed tannins.
Sonication is the act of applying sound energy to agitate particles in a sample, for various purposes such as the extraction of multiple compounds from plants, microalgae and seaweeds. [ 1 ] Ultrasonic frequencies (> 20 kHz) are usually used, leading to the process also being known as ultrasonication or ultra-sonication.
For insulating materials (both solid and liquid), [6] probing charge dynamics with microwaves is a part of dielectric spectroscopy.Amongst the conductive materials, superconductors are a material class that is often studied with microwave spectroscopy, giving information about penetration depth (governed by the superconducting condensate), [4] [7] energy gap (single-particle excitation of ...