Ash (analytical chemistry)
Encyclopedia
In analytical chemistry
, ashing is the process of mineralization
for preconcentration of trace substances prior to chemical analysis. Ash is the name given to all non-aqueous residue that remains after a sample is burned
, and consist mostly of metal oxide
s.
Ash is one of the components in the proximate
analysis of biological materials, consisting mainly of salty, inorganic constituents. It includes metal salt
s which are important for processes requiring ion
s such as Na+ (Sodium), K+ (Potassium), Ca2+ (Calcium). It also includes trace mineral
s which are required for unique molecules, such as chlorophyll
and hemoglobin
.
shows:
Typical honey analysis
In this example the ash would include all the mineral
s in honey.
Analytical chemistry
Analytical chemistry is the study of the separation, identification, and quantification of the chemical components of natural and artificial materials. Qualitative analysis gives an indication of the identity of the chemical species in the sample and quantitative analysis determines the amount of...
, ashing is the process of mineralization
Mineralization
Mineralization may refer to:* Mineralization , the process through which an organic substance becomes impregnated by inorganic substances...
for preconcentration of trace substances prior to chemical analysis. Ash is the name given to all non-aqueous residue that remains after a sample is burned
Combustion
Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame...
, and consist mostly of metal oxide
Oxide
An oxide is a chemical compound that contains at least one oxygen atom in its chemical formula. Metal oxides typically contain an anion of oxygen in the oxidation state of −2....
s.
Ash is one of the components in the proximate
Proximate
Proximates are used in the analysis of biological materials as a decomposition of a human-consumable good into its major constituents.What people consider proximates may vary, but usually includes:* Water* Carbohydrates* Proteins* Dietary fibres...
analysis of biological materials, consisting mainly of salty, inorganic constituents. It includes metal salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
s which are important for processes requiring ion
Ion
An ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
s such as Na+ (Sodium), K+ (Potassium), Ca2+ (Calcium). It also includes trace mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
s which are required for unique molecules, such as chlorophyll
Chlorophyll
Chlorophyll is a green pigment found in almost all plants, algae, and cyanobacteria. Its name is derived from the Greek words χλωρος, chloros and φύλλον, phyllon . Chlorophyll is an extremely important biomolecule, critical in photosynthesis, which allows plants to obtain energy from light...
and hemoglobin
Hemoglobin
Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...
.
Example
For instance, the analysis of honeyHoney
Honey is a sweet food made by bees using nectar from flowers. The variety produced by honey bees is the one most commonly referred to and is the type of honey collected by beekeepers and consumed by humans...
shows:
Typical honey analysis
- FructoseFructoseFructose, or fruit sugar, is a simple monosaccharide found in many plants. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into the bloodstream during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847...
: 38% - GlucoseGlucoseGlucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
: 31% - SucroseSucroseSucrose is the organic compound commonly known as table sugar and sometimes called saccharose. A white, odorless, crystalline powder with a sweet taste, it is best known for its role in human nutrition. The molecule is a disaccharide composed of glucose and fructose with the molecular formula...
: 1% - WaterWaterWater is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
: 17% - Other sugarsSugarSugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...
: 9% (maltoseMaltoseMaltose , or malt sugar, is a disaccharide formed from two units of glucose joined with an αbond, formed from a condensation reaction. The isomer "isomaltose" has two glucose molecules linked through an α bond. Maltose is the second member of an important biochemical series of glucose chains....
, melezitoseMelezitoseMelezitose, also spelled melicitose, is a nonreducing trisaccharide sugar that is produced by many plant sap eating insects, including aphids such as Cinara pilicornis by an enzyme reaction. This is beneficial to the insects, as it reduces the stress of osmosis by reducing their own water potential...
) - Ash: 0.17%
In this example the ash would include all the mineral
Dietary mineral
Dietary minerals are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen present in common organic molecules. Examples of mineral elements include calcium, magnesium, potassium, sodium, zinc, and iodine...
s in honey.
See also
- oxideOxideAn oxide is a chemical compound that contains at least one oxygen atom in its chemical formula. Metal oxides typically contain an anion of oxygen in the oxidation state of −2....
s, e.g. Al2O3, CaO, Fe2O3, MgO, MnO, P2O5, K2O, SiO2 - carbonates: Na2CO3 (aka soda ash), K2CO3 (aka potashPotashPotash is the common name for various mined and manufactured salts that contain potassium in water-soluble form. In some rare cases, potash can be formed with traces of organic materials such as plant remains, and this was the major historical source for it before the industrial era...
), - bicarbonateBicarbonateIn inorganic chemistry, bicarbonate is an intermediate form in the deprotonation of carbonic acid...
s, e.g. NaHCO3 (aka baking sodaSodium bicarbonateSodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula Na HCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda . The natural mineral form is...
),
- SulfateSulfateIn inorganic chemistry, a sulfate is a salt of sulfuric acid.-Chemical properties:...
s: sulfate ash according to Ph. Eur.