Dimethyl dicarbonate
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| General | ||||||||||||||||
| Surname | Dimethyl dicarbonate | |||||||||||||||
| other names |
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| Molecular formula | C 4 H 6 O 5 | |||||||||||||||
| Brief description |
colorless, clear liquid with a fruity, ester-like odor |
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| properties | ||||||||||||||||
| Molar mass | 134.09 g mol −1 | |||||||||||||||
| Physical state |
liquid |
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| density |
1.25 g cm −3 |
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| Melting point |
17 ° C |
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| boiling point |
172 ° C (decomposition) |
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| solubility |
poor in water (~ 35 g l −1 at 20 ° C) with decomposition |
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| safety instructions | ||||||||||||||||
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| Toxicological data | ||||||||||||||||
| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | ||||||||||||||||
Dimethyl dicarbonate (DMDC), also dimethylpyrocarbonate (DMPC), is an ester of pyrocarbonic acid.
properties
The flash point is 85 ° C, the explosion limits are between 3% (lower value) and 29.9% (upper value), the decomposition temperature is 172 ° C.
use
As a food additive with the number E 242, dimethyl dicarbonate (DMDC) is a declaration-free cold disinfectant and kills typical beverage spoilers such as fermentation yeast by carbomethoxylating proteins .
According to the additive approval ordinance for non-alcoholic, flavored drinks and wine, dimethyl dicarbonate is approved according to § 5 for alcohol-free wine and liquid tea concentrate. A maximum of 250 mg per liter may be added. According to EC regulation VO (EG) 606/2009 (EU Oenology Codex Regulation) Annex IA No. 34, dimethyl dicarbonate is permitted for grape must intended for direct human consumption, table wine, sparkling wine, sparkling wine, liqueur wine and quality wine. A maximum of 200 mg per liter may be added, and no more dimethyl dicarbonate may be detectable in the finished product. So far, the use of a residual sugar content of 5 g / l of the wine was permitted, according to the latest regulation (EC) No. 315/2012 (Appendix 6) DMDC can only be used for semi-dry, sweet and sweet wines.
The addition must be made with a dosing device. Simply stirring in causes the container to sink and therefore has no effect. It is sold by Lanxess under the trade name Velcorin ® .
compatibility
After adding to the drink, dimethyl dicarbonate reacts with the water it contains, depending on the temperature, in about 4 hours to form methanol and carbon dioxide, natural components of many drinks such as fruit and vegetable juices, and is no longer available when you buy it. The methanol produced in small quantities can be assessed toxicologically as harmless.
Depending on the ingredients, i. H. in the presence of ammonium ions (NH 4 + ) and in aqueous-acidic solution, however, the smallest amounts of O -methyl carbamate ( O -methyl urethane ) can form. This compound has been well studied toxicologically and has been shown to cause cancer in rats. O -methyl carbamate has been detected in wines disinfected with dimethyl dicarbonate. It's on the California state's list of cancer-causing substances.
Until 1973 diethyl dicarbonate was used in place of dimethyl dicarbonate. Under the same conditions, this forms O -ethyl carbamate ( ethyl urethane ), which is more toxic than O- methyl carbamate. For this reason, diethyl dicarbonate was taken off the market in 1973 and dimethyl dicarbonate was used as a subsequent active ingredient.
O- methyl carbamate is sometimes mistakenly associated with carbamates from crop protection. Carbamates from crop protection are used as insecticides , fungicides and herbicides and are chemically much more complex N- alkyl carbamates. The greatest risk of confusion is with the class of fungicidally active N -methyl carbamates, because N - and O - are often left out, thus simulating an identity.
Asthmatics should not stay in rooms where dimethyl dicarbonate is used, as the substance can trigger asthma attacks.
Disintegration time of dimethyl dicarbonate
The pH value has only a minor influence on the decay, the decisive factor is the temperature according to the RGT rule :
- at 10 ° C → approx. 5 hours
- at 20 ° C → approx. 2 hours
- at 30 ° C → approx. 1 hour
Reaction products of DMDC with beverage ingredients
- Alcohol content> 1% by volume:
→ methyl ethyl carbonate + carbon dioxide + methanol
- Ammonia, amines, amino acids, phenols:
→ methyl carbamate + carbon dioxide + methanol
Individual evidence
- ↑ Entry on E 242: Dimethyl dicarbonate in the European database for food additives, accessed on June 27, 2020.
- ↑ Entry on dimethyl dicarbonate. In: Römpp Online . Georg Thieme Verlag, accessed on May 5, 2014.
- ↑ a b c d Data sheet dimethyl dicarbonate (PDF) from Merck , accessed on March 25, 2011.
- ↑ a b c d e f Entry on dimethyl dicarbonate in the GESTIS substance database of the IFA , accessed on December 16, 2019(JavaScript required) .
- ↑ REGULATION (EC) No. 2165/2005 OF THE COUNCIL of December 20, 2005 amending Regulation (EC) No. 1493/1999 on the common organization of the market in wine.
- ↑ National Toxicology Program: Toxicology and Carcinogenesis Studies of Methyl Carbamate (CAS No. 598-55-0) in F344 / N Rats and B6C3F1 Mice (Gavage Studies). ( Memento of June 14, 2006 in the Internet Archive ) In: National Toxicology Program technical report series. Volume 328, November 1987, pp. 1-176. PMID 12732908 .
- ↑ Chemicals Known to the State to Cause Cancer or Reproductive Toxicity ( Memento of May 12, 2006 in the Internet Archive ) (pdf; 154 kB).
- ↑ Dimethyl dicarbonate - a new reducing substance for non-alcoholic, fruit-juice-containing soft drinks., Genth, H., Erfrischungsgetränk 13, 1979.