Disodium Methylarsonate

• CAS: 144-21-8
• Catalog Number: ACM144218
• Category: Main Products
• Molecular Weight: 183.94
• Molecular Formula: CH₃AsO₃·2Na
• Synonyms: ansar184;ansar8100;ansardsmaliquid;arrhenal;arsinyl;Arsonicacid,methyl-,disodiumsalt;arsynal;cacodylnew
• IUPAC Name: DSMA
• Boiling Point: 165ºC
• Melting Point: 132-139ºC
• Density: 1.15
• Appearance: White Solid
• Exact Mass: 183.90900
• Hazard Statements: Xn,N,T
• Packing Group: III
• Safety Description: 26-61-60-45-28-20/21

Case Study

Speciation Analysis of Arsenic Compounds Such as Disodium Methylarsonate by DESI-MS

de Abreu, Lívia Botelho, et al. Analytical and bioanalytical chemistry, 2013, 405, 7643-7651.

Desorption electrospray ionization mass spectrometry (DESI-MS) was applied to quickly and reliably detect different chemical forms of arsenic compounds in fern leaves, including inorganic (As(V) and As(III) and organic (dimethylarsinic acid-DMA: (CH3)2AsO(OH) and disodium methyl arsonate hexahydrate-MMA: CH3AsO3·2Na·6H2O) arsenic compounds. The results showed that the positive ion mode can be used to detect organic and inorganic arsenic compounds. The negative ion mode is only suitable for the detection of As(V) speciation.
Speciation by DESI-MS/MS: profile of standard DMA/MMA species
· In positive mode, DMA was identified as the cationic species [(CH3)2As(O)(OH)+H]+ with a mass-to-charge ratio (m/z) of 139. This species primarily dissociated by losing one molecule of H2O, resulting in the product ion with an m/z of 121 (Fig. 1a). Additionally, another ion was detected as [(CH3)2As(O)(OH)+H2O+H]+ at m/z 157, which dissociated through the loss of one (m/z 139) or two molecules of H2O (m/z 121) (Fig. 1b).
· Conversely, MMA was characterized by the cations at m/z 203 and 185, linked to the sodiated adducts [CH3As(O)(ONa)2+H2O+H]+ and [CH3AsO(ONa)2+H]+, respectively (Fig. 1d and e). Both of these cations mainly fragmented through the loss of H2O, yielding product ions at m/z 185 and 167. Additionally, the parent ion at m/z 203 also underwent fragmentation via the loss of CH3OH, producing a product ion at m/z 171. These findings for DMA and MMA align with previously published literature. Another cation associated with MMA, [CH3As(O)(OH)2+H]+ at m/z 141, was also detected under these conditions (Fig. 1c). Its mass-selection and fragmentation predominantly led to a product ion resulting from the loss of H2O, with an m/z of 123.

Custom Q&A

What is the chemical formula of Disodium Methylarsonate?

The chemical formula of Disodium Methylarsonate is CH3AsNa2O3.

What are the synonyms of Disodium Methylarsonate?

The synonyms of Disodium Methylarsonate are Disodium methylarsonate, DISODIUM METHANEARSONATE, DSMA, and Sodium methylarsonate.

What is the molecular weight of Disodium Methylarsonate?

The molecular weight of Disodium Methylarsonate is 183.934 g/mol.

What is the parent compound of Disodium Methylarsonate?

The parent compound of Disodium Methylarsonate is Methylarsonic acid.

What are the component compounds of Disodium Methylarsonate?

The component compounds of Disodium Methylarsonate are Methylarsonic acid and Sodium.

When was Disodium Methylarsonate created?

Disodium Methylarsonate was created on August 8, 2005.

When was Disodium Methylarsonate last modified?

Disodium Methylarsonate was last modified on October 21, 2023.

What is the IUPAC name of Disodium Methylarsonate?

The IUPAC name of Disodium Methylarsonate is disodium;methyl-dioxido-oxo-λ5-arsane.

What is the InChIKey of Disodium Methylarsonate?

The InChIKey of Disodium Methylarsonate is SDIXRDNYIMOKSG-UHFFFAOYSA-L.

What is the melting point of Disodium Methylarsonate?

The melting point of Disodium Methylarsonate is greater than 355 °C.