EVISA is providing a list of terms used in the area of speciation and fractionation analysis. Since speciation analysis is a field of analytical chemistry that is specified by a pronounced interdisciplinary cooperation between different sciences such as biochemistry, medicine, biology, environmental sciences, nutritional sciences and material sciences its terminology is a complex mixture of terms used in all these.
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Determined by SnCl2 reduction on acidified samples, includes inorganic complexes, labile organic associations, elemental mercury, and labile particulate mercury. Doesn't measure organic forms (C-Hg bound) of mercury such as methylmercury. Same as reactive mercury.
Adenosylcobalamin
is a cobalamin derivative in which the ß-substituent is deoxyadenosyl
(see the red ligand in left figure). It is one of two metabolically
active forms synthesized upon ingestion of vitamin B12 and is the
predominant form in the liver; it acts as a coenzyme in the reaction
catalyzed by methylmalonyl-CoA mutase.
Cobalamins are coenzymatically active forms of vitamin B12
(cyanocobalamin) which is a water-soluble vitamin and a
nutrient essential for all cells. Cobalamin is a
substituted corrin-Co(III) complex (see blue structure in left figure)
in which the cobalt atom is bound to the four nitrogen atoms of the
corrin ring, an axial group R and 5,6-dimethylbenzimidazole (DMBI, see
green part in left figure). The latter is linked to the cobalt by the
N-3 nitrogen atom and is bound to the C-1 carbon of a ribose molecule
by the N-1 nitrogen atom. Various forms of the vitamin are known with
different R groups such as R = CN, cyanocobalamin; R = OH,
hydroxocobalamin; R = CH3, methylcobalamin; R = adenosyl, coenzyme B-12
(shown here).
general term for the introduction of an alkyl group into a compound and is more specifically known as methylation, ethylation, propylation, butylation, etc., depending upon the alkyl group inserted.
Natural arsenolipids are analogues of neutral lipids, like
monoglycerides, glycolipids, phospho- and also phosphonolipids. They
have been found in microorganisms, fungi, plants, lichens, in marine
mollusks, sponges, other invertebrates, and in fish tissues.
Arsenolipids are thought to be end products of arsenate detoxification
processes, involving reduction and oxidative methylation and
adenosylation.
Source:
Valery M. Dembitsky, Dmitrii O. Levitsky, Arsenolipids, Progress in Lipid Research, 43/5 (2004) 403-448.
Arsenoribofuranosides are organoarsenicals containing a pentose moiety as part of their molecular structure (see figure), which explains why they are commonly referred to arsenosugars.
Arsenosugars are major arsenic compounds in algae but are reported to be present in significant concentrations in other marine organisms such as bivalves. This class of compounds has been raising growing concern since recent reports indicating the possibility of metabolizing arsenosugars to the carcinogenic dimethylarsinic acid (DMAA) by the human body.
Bis(maltolato)oxovanadium(IV) (BMOV) can be synthesized by simple metathesis of vanadyl sulfate trihydrate and maltol (3-hydroxy-2-methyl-4-pyrone) (1:2). The ligand itself is commercially available and is an approved food additive in many countries, including Canada, the United Kingdom, and the United States. BMOV can be prepared in >90% yield in water, has a molecular weight of 317 and is soluble (millimolar scale) in a number of organic solvents as well as water. These properties together (neutral charge and aqueous solubility) contribute to high oral bioavailability. With these considerations in mind, the pentacoordinate, oxovanadium(IV) complex was developed, specifically as a potential insulin-mimetic agent.
Also called the Challenger scheme, which was proposed by Frederick Challenger. The mechanism is a series of metabolic reduction and oxidative methylation reactions that begin with the reduction of inorganic arsenate to inorganic arsenite and ultimately ends with the formation of trimethylarsine.
The particulate material packed inside the column; also called the stationary phase. This usually consists of silica- or polymer-based particles, often chemically bonded with a chemical function al group. For analytical work, 3µm or 5µm spherical particles are used; for semi-preparative, 10µm or larger spherical or irregular particles are favored. The most common packings are as follows:
Octadecyl (ODS, C18) the most popular phase, used for reversed-phase HPLC
Octyl (C8) more polar than C18, also a popular reversed-phase column
TMS (methyl, C1) weakly retentive in reversed-phase
Silica (Si) unbonded silica used in normal phase mode, popular for preparative LC.
Phenyl, Cyano, Amino specialty phases used for specific applications.
A small-molecule organic arsenical with potential antineoplastic activity. Although the exact mechanism of action is unclear, darinaparsin, a highly toxic metabolic intermediate of inorganic arsenicals (iAs) that occurs in vivo, appears to generate volatile cytotoxic arsenic compounds when glutathione (GSH) concentrations are low. The arsenic compounds generated from darinaparsin disrupt mitochondrial bioenergetics, producing reactive oxygen species (ROS) and inducing ROS-mediated tumor cell apoptosis; in addition, this agent or its byproducts may initiate cell death by interrupting the G2/M phase of the cell cycle and may exhibit antiangiogenic effects. Compared to inorganic arsenic compounds such as arsenic trioxide (As2O3), darinaparsin appears to exhibit a wide therapeutic window.
Dimethylarsinic acid (DMAV) is an organoarsenic compound that has been identified as one of the main metabolites found in urine of humans (and animals) after ingestion of inorganic arsenic compounds.
Dimethylarsinothioic acid (DMAS) also called dimethylthioarsinic acid (DMTAV) is an organoarsenic compound that has recently
been identified as human metabolite after exposure toward both the human
carcinogen inorganic arsenic and arsenosugars, which are the major
arsenical constituents of marine algae. It was earlier already identified as a metabolite in sheep's urine after ingestion of seaweed containing arsenosugars.
Dimethylarsinothioyl acetic acid (DMAAS) is an organoarsenic compond that has been identified as a minor metabolite in sheep's urine after ingestion of seweed containing arsenosugars.
An organic trivalent arsenical with the composition of (CH3)2As(OH), abbreviated DMA(III), see Figure (compare with dimethylarsinic acid, monomethylarsonic acid, and monomethylarsonous acid).
Dimethylarsinoyl acetic acid (DMAA) is an organoarsenic compound found in sheep's urine as a minor metabolite after ingestion of seaweed containing arsenosugars.
Dimethylarsinoylethanol (DMAE) was found in sheep's urine as a metabolite after seaweed consumption containing arsenosugars as the main arsenic compounds.
Dimethylarsonyldimethylarsinic acid has been identified as one of the organoarsenic species present in some rice grain samples. It is present in some rice samples both as oxide and as mono- and di-thiolated compound. The thiolated forms are highly sensitive to the extraction conditions, especially the application of heat and the use of hydrogen peroxide.
Organomercury compound consisting of a single mercury atom and two methyl groups [(CH3)2Hg], highly volatile and not persistent in the environment. As an organic mercury compound, it may
form when mercury combines with carbon covalently (shares electrons forming a
strong bond). Dimethylmercury is poisonous to the nervous system (a neurotoxin),
it readily crosses the blood-brain barrier and causes a lack of coordination,
sensory disturbance and changes in mental state. Dimethylmercury inhibits
several stages of neurotransmission in the brain.
(CH3)2Se The volatile organoselenium compound dimethylselenide is a metabolite in the primary pathway of the metabolism of selenite by animals and man.
Dimethylsilane and tetramethylsilane are used as a Chemical Vapor Deposition (CVD) silicon precursor for low k dielectric layers in damascene metallization applications.
(CH3)2Te - Dimethyltelluride is generated through methylation from organic and an inorganic salt of tellurium. The volatile metalloid compound has been identified in a variety of anthropogenic gases, e.g. landfill gas and sewage sludge digester gas.
Fenbutatin
oxide is an organotin compound used as an insecticide. It acts as
contact and stomach acaricides for the control of various mites in a
variety of fruit, vegetable and field crops.
A superparamagnetic iron oxide nanoparticle coated with a low molecular
weight semi-synthetic carbohydrate, polyglucose sorbitol carboxymethyl
ether, with potential anti-anemic and imaging properties. After
intravenous administration, ferumoxytol replaces iron stores with fewer
side effects compared to the use of oral iron. In addition, this agent
generates T1 relaxation, producing a magnetic field and enhancing T2
relaxation, thereby darkening contrast media-containing structures in
magnetic resonance imaging (MRI). Due to small particle size,
ferumoxytol remains in the intravasculature for a prolonged period and
so may be used as a blood pool agent.
A gadolinium-based, hydrophilic, macrocyclic, electrically
neutral contrast agent used in contrast-enhanced MRI (CE-MRI).
Gadobutrol is a non-ionic, paramagnetic complex consisting of
gadolinium (Gd3+) chelated with the macrocyclic compound
dihydroxy-hydroxymethylpropyl-tetraazacyclododecane-triacetic acid
(butrol). Following intravenous administration, gadobutrol may increase
MRI sensitivity for the detection of tumors and inflammatory and
demyelinating diseases of the central nervous system (CNS) which are
associated with areas with blood-brain
barrier defects due to altered perfusion or an enlarged extracellular
space. This agent is eliminated in an unchanged form via the kidneys;
extra-renal elimination is negligible.
Lobaplatin (D-19466; 1,2-diammino-methyl-cyclobutaneplatinum(II)-lactate) is a new anticancer agent and a representative of the third-generation platinum compounds. The metallodrug lobaplatin consists of a nearly 50%/50% mixture of two diastereoisomers: (a) the SSS configuration (LP-D1); and (b) the RRS configuration (LP-D2) (see left.) . The compound has shown antitumor activity in human lung, gastric, testicular, and ovarian cancer xenografts, with incomplete cross-resistance to cisplatin in vitro and in vivo.
Mercury, also called quicksilver, is a chemical element in the periodic table that has the symbol Hg (Latinized Greek: hydrargyrum, meaning watery or liquid silver) and atomic number 80. A heavy, silvery transition metal, mercury is one of five elements that are liquid at or near room temperature and pressure. (The others are the metals caesium, francium, and gallium, and the non-metal bromine.)
Mercury is used in thermometers, barometers and other scientific apparatus, though concerns about the element's toxicity have led to mercury thermometers being largely phased out in clinical environments in favour of alcohol-filled, digital or thermistor-based instruments. It remains in use in a number of other ways in scientific and scientific research applications, and in dental amalgam. Mercury is mostly obtained by reduction from the mineral, cinnabar.
Mercury occurs in deposits throughout the world and it is relatively harmless in an insoluble form, such as mercuric sulfide, but it is poisonous in soluble forms such as mercuric chloride or methylmercury.
This selenosugar has been identified as the main selenium metabolite occuring in human background urine and in urine after ingestion of sodium selenite, L-selenomethionine or DL-selenomethionine.
The deacylate analog of the selenosugar methyl-2-acetamido-2-deoxy-1-seleno-ß-D-galactopyranoside has been identified as a minor Se-metabolite in human urine.
(CH3AsS)x : A colorless compound whose flakes melt at 110°C;
insoluble in water; used as a fungicide in treating cotton seeds. Also
known as thioarsorosomethane (Rhizoctol, Asozin, MAS, Monkil or Wrabasulf : CAS 2533-82-6, MW 122.023)
Methylarsonic acid (MAV) is an organoarsenic compound found as a minor metabolite in urine of humans and animals after ingestion of inorganic arsenic compounds.
Addition of a methyl group to a molecule or atom, either by a microbial activity (biomethylation) or by purely chemical reaction (abiotic methylation).
Methylcyclopentadienylmanganese tricarbonyl (MMT) has been used as a partial substitute for alkyllead compounds in its role as an antiknock compounds to improve the petrol octane rating.
Formula: C9H7MnO3 Molecular Weight: 218.09 CAS Registry Number: 12108-13-3
Alkylmercury compounds having methyl groups. Includes both mono- and dimethylmercury.
In fact,
methylmercury is not a compound in itself but a cation,
CH3Hg+, which forms one part of methylmercury compounds;
usually methylmercury salts.
Dimethylmercury is one methylmercury
compound that is not a salt. The methylmercury cation is normally associated
with either a simple anion, like chloride (Cl-), or a large
molecule (e.g. a
protein) with negative and positive
charges. The methylmercury cation is the most
toxic form of mercury, able to inhibit fetal
brain development, which results in the behavioural changes and reduced
cognitive and motor ability.
Methylselenocysteine, sometimes called Se-methylselenocysteine. The methylated form of SeCys. Produced naturally by brassicas, alliums and Se hyperaccumulators when grown in the presence of Se (as selenate, selenite or certain organoselenium compounds), but at very low amounts in other crops.
A chemical species containing pentavalent arsenic, sulfide, and methyl groups, as examples: (CH3)AsO2S2−, (CH3)AsOS22−, (CH3)2AsOS−, and (CH3)2AsS2− (compare with thioarsenic, thioarsenate, and thioarsenite).
An organic pentavalent arsenical with the composition of (CH3)AsO(OH)2, abbreviated MMA(V), see Figure (compare with dimethylarsinous acid, dimethylarsinic acid, and monomethylarsonous acid).
Propylation is a derivatization technique in which the analyte species
is transformed by adding propyl groups. For this alkylation either a
Grignard reagent based on propylmagnesium or sodium tetrapropylborate
can be used. Propylation is especially usefull for the analysis of
methyl- or ethyl-species, for which methylation or ethylation would
destroy molecular information.
“Easily reducible,” determined by SnCl2 reduction on acidified samples,
includes inorganic complexes, labile organic associations, elemental
mercury, and labile particulate mercury, doesn't include C-Hg bound
mercury such as methylmercury and dimethylmercury. Same as acid labile
mercury.
Stir bar sorptive extraction (SBSE) is a solid phase extraction (SPE) method in which the sorbent is a coating of a solid magnetical stir bar. SBSE applies stir bars varying in length from 1 to 4 cm coated with a relatively thick layer (0.3-1 mm) of polydimethylsiloxane (PDMS) resulting in PDMS volumes varying from 55 µL to 220 µL. After a certain stirring time, the stir bar is removed from the aqueous sample and thermally desorbed on-line with a gas chromatograph. Due to the much larger volume of the PDMS-phase extraction efficiency is far better than for SPME.
A naturally occurring organoselenium compound found in many plants,
including garlic, onions, and broccoli, with potential antioxidant and
chemopreventive activities. Se-Methyl-seleno-L-cysteine (MSC) is an
amino acid analogue of cysteine in which a methylselenium moiety
replaces the sulphur atom of cysteine. This agent acts as an
antioxidant when incorporated into glutathione peroxidase and has been
shown to exhibit potent chemopreventive activity in animal models.
Se-methylselenoneine is a Se-metabolite found in human urine most likely as a result of methylation of dietary selenoneine. Higher concentrations of this species in human urine are probably associated with the consumption of tuna which is a rich source of selenoneine.
Selenomethionine is an selenoamino acid (amino acid containing selenium). The L-isomer of selenomethionine, known as Se-met, is a common natural food source of selenium. It can not be synthesized by higher animals, but can be obtained from plant material.
Chemical formula: C5H11NO2Se IUPAC name: 2-amino-4-methylselanyl-butanoic acid
A histidine derivative that is Nα,Nα,Nα-trimethyl-L-histidine substituted by a selenoxo group at position 2 on the imidazole ring. This selenium-containing antioxidant was found in tuna blood and is a major selenium compound in fish muscle. Ths compound has strong antioxidant capacity and binds to heme proteins, such as hemoglobin and myoglobin, to protect them from iron auto-oxidation, and it reacts with radicals and methylmercury (MeHg). Formula: C9H15N3O2Se Mol. Weight: 276.19000
Polymerized siloxanes with organic side chains (R ≠ H) are commonly known as silicones or as polysiloxanes. Representative examples are [SiO(CH3)2]n (polydimethylsiloxane) and [SiO(C6H5)2]n (polydiphenylsiloxane). These compounds can be viewed as a hybrid of both organic and inorganic compounds. The organic side chains confer hydrophobic properties while the -Si-O-Si-O- backbone is purely inorganic.
A siloxane is any chemical compound composed of units of the form R2SiO, where R is a hydrogen atom or a hydrocarbon group. A siloxane has a branched or unbranched backbone of alternating silicon and oxygen atoms -Si-O-Si-O-, with side chains R attached to the silicon atoms. The word siloxane is derived from the words silicon, oxygen, and alkane.
Spiroplatin is a second generation metallodrug and analgue for cisplatin, developed for cancer therapy. Spiroplatin induces DNA cross-links, thereby
inhibiting DNA replication and RNA and protein synthesis. Similar to
other platinum compounds, this agent has been shown to be mutagenic and
carcinogenic.
Steam distillation is a special type of distillation (a separation
process) for temperature sensitive materials that tend to decompose at
sustained high temperatures. Separation by normal distillation would
then not be an option, so water or steam are introduced into the
distillation apparatus. By adding water or steam the boiling point of
the compounds is depressed, allowing them to evaporate at lower
temperatures, preferably below the temperatures at which the
deterioration of the material becomes appreciable. If the substances to
be distilled are very sensitive to heat, steam distillation can also be
combined with vacuum distillation. After destillation the vapors are
condensed as usual, usually yielding a two-phase system of water and
the organic compounds, allowing for simple separation.
Steam distillation has been evaluated as a technique for the separation
of methylmercury from different environmental sample materials.
Tetramethylammonium hydroxide (TMH) is an effective etchant and chelating agent ideal for removing residue and contaminants from semiconductor and electronic components. It also is often used to solubilze biological materials by alkaline hydrolysis.
An aqueous species, such as H2AsO3S− and H2AsS2O2−, that contains pentavalent arsenic and sulfide (compare with arsenate, thioarsenic, thioarsenite, and methylthioarsenate).
An aqueous species, such as HAs3S62− and H2AsO3S−, that contains sulfide and arsenic, either as arsenide (As3−), As3+, or As5+ (compare with arsenosulfide, methylthioarsenate, thioarsenate, and thioarsenite).
An aqueous species, such as H2As3S6−, that contains trivalent arsenic and sulfide (compare with arsenite, thioarsenic, thioarsenate, and methylthioarsenate).
(CH3)3Bi - trimethylbismuthine, a volatile metalalkyl compound, has been identified in a variety of anthropogenic gases, e.g. landfill gas and sewage sludge digester gas. Biomethylation of inorganic bismuth compounds is performed by different microorganisms, such as bacteria.
In semiconductor manufacturing, trimethyl gallium (TMGa) is used in OrganoMetallic Vapor Phase Epitaxy (MOCVD) for the deposition of epitaxial GaAs or GaN layers.
(CH3)3Ga ; Gallium trimethyl CAS Number : 1445-79-0
(CH3)3Sb - Trimethylstibine, also called trimethyl antimony, is generated through methylation from organic and an inorganic salt of antimony by microorganisms. The volatile metalloid compound has been identified in a variety of anthropogenic gases, e.g. landfill gas and sewage sludge digester gas.
The organoselenium species trimethylselenonium has been reported to be a Se-metabolite in rat urine (especially at enhanced exposure). In urine of healthy humans this species has not been unambigously confirmed.
A vitamin synthesized by microorganisms and conserved in
animals in the liver. Deficiency or collective uptake of vitamin B-12
leads to pernicious anemia. It consists of cobalamin, a substituted
corrin-Co(III)
complex in which the cobalt atom is bound to the four nitrogen atoms of
the corrin ring, an axial group A and 5,6-dimethylbenzimidazole.
Various forms of the vitamin are known with different A groups such as
A = CN,
cyanocobalamin; R = OH, hydroxocobalamin; R = CH3, methylcobalamin; R =
adenosyl, coenzyme B-12.
Adenosylcobalamin
is a cobalamin derivative in which the ß-substituent is deoxyadenosyl
(see the red ligand in left figure). It is one of two metabolically
active forms synthesized upon ingestion of vitamin B12 and is the
predominant form in the liver; it acts as a coenzyme in the reaction
catalyzed by methylmalonyl-CoA mutase.
Bis(maltolato)oxovanadium(IV) (BMOV) can be synthesized by simple metathesis of vanadyl sulfate trihydrate and maltol (3-hydroxy-2-methyl-4-pyrone) (1:2). The ligand itself is commercially available and is an approved food additive in many countries, including Canada, the United Kingdom, and the United States. BMOV can be prepared in >90% yield in water, has a molecular weight of 317 and is soluble (millimolar scale) in a number of organic solvents as well as water. These properties together (neutral charge and aqueous solubility) contribute to high oral bioavailability. With these considerations in mind, the pentacoordinate, oxovanadium(IV) complex was developed, specifically as a potential insulin-mimetic agent. 
Dimethylarsinic acid (DMAV) is an organoarsenic compound that has been identified as one of the main metabolites found in urine of humans (and animals) after ingestion of inorganic arsenic compounds.
Dimethylarsinothioic acid (DMAS) also called 
Dimethylarsinothioyl acetic acid (DMAAS) is an organoarsenic compond that has been identified as a minor metabolite in sheep's urine after ingestion of seweed containing arsenosugars.
An organic trivalent arsenical with the composition of (CH3)2As(OH), abbreviated DMA(III), see Figure (compare with dimethylarsinic acid, monomethylarsonic acid, and monomethylarsonous
Dimethylarsinoyl acetic acid (DMAA) is an organoarsenic compound found in sheep's urine as a minor metabolite after ingestion of seaweed containing arsenosugars.
Dimethylarsinoylethanol (DMAE) was found in sheep's urine as a metabolite after seaweed consumption containing 
in some rice grain samples. It is present in some rice samples both as oxide and as mono- and di-thiolated compound. The thiolated forms are highly sensitive to the extraction conditions, especially the application of heat and the use of hydrogen peroxide.
Dimethyldithioarsinic acid (DMDTAV) has recently been found in landfill leachates as a microbial degradation product.
Dimethylsilane and tetramethylsilane are used as a Chemical Vapor Deposition (CVD) silicon precursor for low k dielectric layers in damascene metallization applications.
Fenbutatin
oxide is an organotin compound used as an insecticide. It acts as
contact and stomach acaricides for the control of various mites in a
variety of fruit, vegetable and field crops. 
Lobaplatin (D-19466; 1,2-diammino-methyl-cyclobutaneplatinum(II)-lactate) is a new anticancer agent and a representative of the third-generation platinum compounds. The metallodrug lobaplatin consists of a nearly 50%/50% mixture of two diastereoisomers: (a) the SSS configuration (LP-D1); and (b) the RRS configuration (LP-D2) (see left.) . The compound has shown antitumor activity in human lung, gastric, testicular, and ovarian cancer xenografts, with incomplete cross-resistance to cisplatin in vitro and in vivo.
This selenosugar has been identified as the main selenium metabolite occuring in human background urine and in urine after ingestion of sodium selenite, L-selenomethionine or DL-selenomethionine.
The deacylate analog of the selenosugar methyl-2-acetamido-2-deoxy-1-seleno-ß-D-galactopyranoside has been identified as a minor Se-metabolite in human urine.
Methylarsonic acid (MAV) is an organoarsenic compound found as a minor metabolite in urine of humans and animals after ingestion of inorganic arsenic compounds.
Methylselenomethione has been reported as a metabolite of the Se metabolism in plants and animals.
Methylsilane is used in the epitaxial Chemical Vapor Deposition (CVD) of germanium doped silicon carbide (Si-Ge-C) layers.
An organic pentavalent arsenical with the composition of (CH3)AsO(OH)2, abbreviated MMA(V), see Figure (compare with dimethylarsinous acid, dimethylarsinic acid, and monomethylarsonous acid).
Stir bar sorptive extraction (SBSE) is a solid phase extraction (SPE) method in which the sorbent is a coating of a solid magnetical stir bar. SBSE applies stir bars varying in length from 1 to 4 cm coated with a relatively thick layer (0.3-1 mm) of polydimethylsiloxane (PDMS) resulting in PDMS volumes varying from 55 µL to 220 µL. After a certain stirring time, the stir bar is removed from the aqueous sample and thermally desorbed on-line with a gas chromatograph. Due to the much larger volume of the PDMS-phase extraction efficiency is far better than for SPME.
Selenomethionine is an selenoamino acid (amino acid containing selenium). The L-isomer of selenomethionine, known as Se-met, is a common natural food source of selenium. It can not be synthesized by higher animals, but can be obtained from plant material.
A siloxane is any chemical compound composed of units of the form R2SiO, where R is a hydrogen atom or a hydrocarbon group. A siloxane has a branched or unbranched backbone of alternating silicon and oxygen atoms -Si-O-Si-O-, with side chains R attached to the silicon atoms. 
Spiroplatin is a second generation metallodrug and analgue for cisplatin, developed for cancer therapy. Spiroplatin induces DNA cross-links, thereby
inhibiting DNA replication and RNA and protein synthesis. Similar to
other platinum compounds, this agent has been shown to be mutagenic and
carcinogenic.
In semiconductor manufacturing, trimethyl gallium (TMGa) is used in OrganoMetallic Vapor Phase Epitaxy (MOCVD) for the deposition of epitaxial GaAs or GaN layers. 
(CH3)3-SiH ; Trimethylsilane 
Trimethylsilanol has been the most abundant compound determined in waste composting gas samples, accompanied by several siloxanes. 
The organoselenium species trimethylselenonium has been reported to be a Se-metabolite in rat urine (especially at enhanced exposure). In urine of healthy humans this species has not been unambigously confirmed.
