Methanethiol

• Methyl mercaptan
• Methylsulfhydrat
• Thiomethanol
• Methyl hydrosulfide
• Methanthioalkohol
• Mercaptomethan

Colorless gas with a pungent odor foul -

Gaseous

-123 ° C

5.96 ° C

170 kPa ( 20 ° C)

Poorly in water: 23.3 g · l-1 (20 ° C)

Risk

0.5 ml · m-3, 1 mg · m-3

-22.9 KJ / mol

Template: Infobox chemical / molecular formula search available

Methanethiol is a colorless, unpleasant smelling of rotten vegetables gas.

Occurrence

Methanethiol occurs naturally in nuts and cheese, but also in the blood, brain and other organs of man and of animals. It occurs when bacterial degradation of proteins. A cause of unpleasant mouth odor in humans - in addition to other volatile sulfur-containing compounds - methanethiol.

Methanethiol is a major breakdown product of Dimethylsulfoniopropionat ( DMSP ), which is found in bacteria in seawater. Therefore, it is detectable in near-surface water. Methanethiol can be converted by bacteria to dimethyl sulfide.

Physiology

Larger amounts of methanethiol, as can occur in the degradation of an excess of the amino acid L- methionine, are partially oxidized in the microsomes of the liver to carbon dioxide and sulfates. The latter is detectable in the urine and lowers the pH.

Properties

Chemically methanethiol belongs to the group of alkanethiols and is a weak acid. Its critical temperature is 196.8 ° C, the critical pressure of 72.4 bar, and the critical density of 0.332 kg / l, and the triple point temperature of -123.0 ° C ( melting temperature).

Use

Methanethiol is added because of its unpleasant and persistent smell natural or propane gas as a warning agent in order to draw attention to leaks ( odorisation ). In addition, particular weed killer for wheat, corn and rice crops can be produced from methanethiol pesticides.