Sodium hydromethylarsenate is a universal plant protection product, but is most often used as a herbicide. It is forbidden to use in Germany, but in the USA it is used to this day. It is a powerful carcinogen of the 1st class . The chemical structure is the acid salt of methyl arsenic acid .
| Sodium hydromethylarsenate | |
|---|---|
| Are common | |
| Systematic name | sodium hydrometilarsenate |
| Abbreviations | MSMA |
| Chem. formula | CH 4 AsNaO 3 |
| Physical properties | |
| condition | odorless colorless crystals [1] |
| Molar mass | 161.95 g / mol |
| Thermal properties | |
| T. melt. | 130-140 ° C |
| Steam pressure | 0.0104 MPa [2] |
| Chemical properties | |
| Solubility in water | practically insoluble [2] |
| Solubility in methanol | 160 g · l −1 at 25 ° C [2] |
| Classification | |
| Reg. CAS number | 2163-80-6 |
| PubChem | |
| Reg. EINECS number | |
| Smiles | |
| Inchi | |
| ChemSpider | |
| Security | |
| LD 50 | 700 mg · kg −1 ( rat , oral) [1] |
| R phrases | R23 / 25 R50 / 53 |
| S-phrases | S20 / 21 S28 S45 S60 S61 |
| H phrases | H301 , H331 , H410 |
| P-phrases | P261 , P273 , P301 + 310 , P311 , P501 |
| GHS icons |   |
Synthesis
Sodium hydromethylarsenate can be synthesized from chloromethane , arsenic (III) oxide , sulfuric acid and sodium hydroxide [3] :
It can also be obtained by methylation of sodium meta arsenite with dimethyl sulfate [3] :
Usage
Sodium hydromethylarsenate is used as a defoliant in cotton growing, especially in Texas and Louisiana and as a herbicide on golf courses [4] .
Approval
In the European Union and Switzerland, this substance is prohibited for use as an active agent of plant protection products [5] .
Notes
- ↑ 1 2 Record of Natriummethylarsonat in the GESTIS Substance Database of the IFA
- ↑ 1 2 3 Robert Krieger (Hrsg.). Hayes' Handbook of Pesticide Toxicology, Band 1 . - Elsevier, 1999 .-- P. 779. - ISBN 978-0-12-374367-1 .
- ↑ 1 2 PubChem 23664719 .
- ↑ MS Cox, PF Bell and JL Kovar, Arsenic supply characteristics of four cotton-producing soils; Plant and Soil Volume 180, Number 1, 11-17, 1996, DOI : 10.1007 / BF00015406 .
- ↑ Generaldirektion Gesundheit und Lebensmittelsicherheit der Europäischen Kommission: EU-Pestiziddatenbank ; Eintrag im nationalen Pflanzenschutzmittelverzeichnis der Schweiz ; abgerufen am 25.