EP0848628B1 - Process using a peracid composition for decontaminating materials contaminated with toxic agents - Google Patents

Description

The present invention relates to a method of decontamination of materials soiled by agents toxic, more particularly using a composition based on peracids ensuring efficient decontamination of materials contaminated by toxic agents such as compounds organophosphorus or organosulfur, without causing degradation notable of said materials

It is known that various organophosphate inhibitor compounds cholinesterases, such as organophosphates, amidophosphates, organoamidophosphates, phosphorothionates, phosphonothionates and phosphoroamidothionates, can be used in agriculture as insecticides and pesticides. On the other hand, some compounds organosulfur are known as blistering agents and used as poisonous agents of war.

Among the best known organophosphorus compounds used as pesticides or insecticides in agriculture, we may especially mention O, O-diethyl-O-p-nitrophenyl phosphate (Paraoxon) and O, O-diethyl-O-p-nitrophenyl phosphorothioate (Parathion), while O-ethyl-S- (diisopropylaminoethyl-2) -methylphosphorothiolate (VX) is a toxic agent of war well known. These compounds work by blocking irreversible nerve transmission, by binding covalent to acetylcholinesterase, causing death by accumulation of acetylcholine in the body. As compound organosulfur used as a war toxicant, we can also cite dichloro-2,2'-diethyl sulfide (Yperite).

It is important to be able to protect yourself in the event intentional or accidental use of such compounds, and in particular to be able to quickly decontaminate and effectively the materials in contact with which they were doors. It is therefore useful to have reagents or compositions capable of destroying almost instantly such organophosphorus and organosulfur compounds.

One of the difficulties encountered in practice is the need to avoid as far as possible from degrade the materials to be decontaminated. So the compositions most effective currently used in the technique of decontamination, are soda solutions in the methylglycol with diethylamine, or hypochlorite calcium, but these solutions are very corrosive.

Numerous studies have shown that nucleophilic compounds have the qualities required to remove toxic substances from the organophosphate and organosulfur series. CA Bunton et al., J. Am. Chem. Soc ., 95 , 2912 (1973), have demonstrated the properties of the hydroxyl ion for this purpose; other reagents have also been proposed, including hydroxamic acids, oximes, mono- and polyphenols, aldehyde hydrates, certain amines, as well as calcium or sodium hypochlorites.

It has also been proposed to use peroxyanions as hydrogen peroxide, tert-butyl hydroperoxide, perborates and peracids, due to their properties at the both nucleophilic and oxidative.

These various compounds can be used in compositions still containing surfactants improving the contact between the reagent used and the agent toxic to eliminate, to speed up decontamination. In in particular, the use of ammonium type surfactants quaternary accelerates the destruction of toxins by a micellar catalysis.

Thus, patent FR-A-2,651,133 describes compositions consisting of solutions containing peracids linear long carbon chain, pH between 6 and 8, generally associated with surfactants such as cetyl trimethyl ammonium bromide, cetyl bromide 2-dimethyl hydroxyethyl ammonium, cetyl methyl bromide bis (hydroxyethyl-2) ammonium or cetyl diaza-1,4-bromide bicyclo (2.2.2) octyl ammonium. Such compositions allow to destroy Paraoxon, VX and Yperite. However, the peracids used are not available in the trade and the stability of the compositions is not satisfactory.

FR-A-2,676,368 describes aqueous compositions based on magnesium monoperoxyphthalate and surfactant of the quaternary ammonium salt type, usable for the decontamination of materials soiled by certain agents neurotoxic, including VX, and vesicants such as yperite.

The destruction of Yperite and neighboring compounds by oxidants, in particular by potassium monopersulfate, has been described by C. Lion et al., Phosphorus, Sulfur and Silicon, 79 , 141-145 (1993), which have shown that the reaction is specific for organosulfur compounds.

There therefore remains a need to be able to have access to compositions capable of destroying effectively and quickly toxic organophosphorus and organosulfur compounds above, in order to decontaminate the materials soiled by these compounds, without degrading them.

• un peracide choisi parmi
  • un imidoperacide représenté par la formule générale (I)
    
    dans laquelle n est un entier compris entre 3 et 8, et R₁, identique ou différent dans chaque groupe -CHR₁-, est un groupe alkyle ou un groupe phényle; et
  • l'acide phtalimidoperpropionique et phtalimidopecaproïque.
  • un diperacide représenté par la formule générale (II) HO₃C ― (CHR₂)_p - CO₃H dans laquelle p est un entier compris entre 2 et 10, et R₂ a la même définition que R₁;
  • les acides perdidécanoïque, perdinonanoïque et perdidodécanoïque, et
• un agent tensio-actif cationique du type ammonium quaternaire.

The subject of the present invention is a process for the decontamination of materials contaminated with toxic organophosphorus or organosulfur agents, using a composition containing a peracid and a surfactant, characterized in that this composition comprises

• a peracid chosen from
  • an imidoperacid represented by the general formula (I)
    
    in which n is an integer between 3 and 8, and R ₁ , identical or different in each group -CHR ₁ -, is an alkyl group or a phenyl group; and
  • phthalimidoperpropionic acid and phthalimidopecaproic acid.
  • a diperacid represented by the general formula (II) HO ₃ C - (CHR ₂ ) _p - CO ₃ H in which p is an integer between 2 and 10, and R ₂ has the same definition as R ₁ ;
  • perdidecanoic, perdinonanoic and perdidodecanoic acids, and
• a cationic surfactant of the quaternary ammonium type.

According to a preferred embodiment of the invention, the composition consists of a solution aqueous pH buffered between 8 and 11, and preferably between 9 and 10.

In formulas (I) and (II) above, R ₁ and R ₂ preferably represent an alkyl group of 1 to 4 carbon atoms, and for example a methyl, ethyl or n-propyl group.

The peracids used in the invention are products available commercially or the preparation of which can be carried out easily by usual techniques, by the action of hydrogen peroxide in an acid medium (for example in cold concentrated sulfuric acid medium) on the corresponding acids. A method of preparing such peracids is described by C. Lion et al. Bull. Soc. Chim . Belg. 99 (2) 127 (1990).

dans laquelle R₁, R₂ et R₃, identiques ou différents, représentent un groupe alkyle ou hydroxyalkyle de 1 à 4 atomes de carbone, R₄ représente un groupe alkyle, linéaire ou ramifié de 11 à 18 atomes de carbone, et X représente un halogène ou un radical hydroxyle.The cationic surfactant of the quaternary ammonium type is preferably represented by the general formula (III):

in which R ₁ , R ₂ and R ₃ , identical or different, represent an alkyl or hydroxyalkyl group of 1 to 4 carbon atoms, R ₄ represents a linear or branched alkyl group of 11 to 18 carbon atoms, and X represents a halogen or a hydroxyl radical.

Among the surfactants represented by the general formula (III) above, use is preferably made for which R ₁ , R ₂ and R ₃ represent a methyl group, an ethyl group or a hydroxyethyl group, R ₄ represents a cetyl group, and X is chlorine, bromine or a radical -OH.

According to an advantageous form of implementation of the invention, the surfactant of general formula (III) is chosen from bromide or cetyl trimethyl chloride ammonium, cetyl dimethyl hydroxyethyl-2 bromide ammonium, cetyl methyl bis (2-hydroxyethyl) bromide ammonium or cetyl diaza-1,4 bicyclo (2.2.2) octyl bromide ammonium.

These surfactants are known and, for the most part, commercially available. They can be prepared by the methods described by CA Bunton et al. (cited above) and by L. Horner et al., Phosphorus and Sulfur, 11 , 339 (1981). For example, cetyl dimethyl hydroxyethyl-2-ammonium bromide can be obtained by refluxing a solution of hexadecyl bromide and dimethylethanolamine in a mixture of acetonitrile and methanol and by recrystallizing the crystals obtained from methanol.

As indicated above, the composition according to the invention preferably comes in the form of a solution buffered aqueous, pH between 8 and 11, preferably between 9 and 10, for example an aqueous solution of a mixture baking soda and sodium bicarbonate.

This aqueous solution is applied to the material to be decontaminate, by spraying, spraying or simple washing, or it is possible to dip the materials in a tank containing a composition according to the invention.

According to a variant of the invention, the peracid and the quaternary ammonium type surfactant, when X is a hydroxyl, can be combined within the same molecule, to form a tetraalkylammonium percarboxylate. Such compound can be obtained by action of the peracid of formula (I) or (II) on a tetraalkylammonium hydroxide, in amounts stoichiometric.

This variant is particularly advantageous because the percarboxylate can be generated in situ, and looks like this in aqueous solution, without the need to use a carbonate buffer which is replaced here by hydroxide tetraalkylammonium.

Tetraalkylammonium hydroxide can be prepared using the method described by L. Sepulveda et al., J. Phys. Chem ., 89 , 5322 (1985), starting from carbon sulphide and sodium ethylate, and action of a tetraalkylammonium bromide in sulfuric medium, then treatment with a base such as barium hydroxide.

The effectiveness of the compositions according to the invention for the decontamination of materials contaminated with compounds organophosphorus or toxic organosulfur has been verified by causing them to act on known compounds such as O, O-diethyl-O-p-nitrophenyl phosphate (Paraoxon), in the series of organophosphorus compounds, and 2-phenyl-2'-chlorodiethyl sulfide, analog of Yperite, in the organosulfur series.

The tests carried out show that the compositions of the invention cause the destruction of compounds such as Paraoxon and the analogue of Yperite practically Instant. This result is obtained with the composition containing the peracid of formula (I) or (II) in combination with the quaternary ammonium type surfactant, as well that with the composition containing a percarboxylate of tetraalkylammonium.

In addition, it can be seen that the composition of the invention has excellent stability over time, unlike to conventional compositions based on peracids, and is not aggressive towards the various materials commonly treated.

The following examples describe the effects in more detail of destruction of Paraoxon and an analog of Yperite by compositions according to the invention comprising either a combination of peracid and surfactant (Example 1), or a tetraalkylammonium percarboxylate (Example 2).

The kinetics of destruction are carried out for the Paraoxon according to a usual technique, in UV spectroscopy at 402 nm, corresponding to the maximum absorption of the p-nitrophenate ion released, at 25 ° C.

The destruction speeds of the Yperite analog above are determined by chromatographic analysis at regular intervals, after addition of a mineral reducer (ferrous sulfate) or organic (triphenylphosphine). We operate at a pH of 9.

Example 1

Table 1 below indicates the half-reaction time (in s.), At 25 ° C., per action of each of the four peracids indicated below, in 2.10 ^-3 M solution at pH 9, on the Paraoxon ( 5.10 ^-5 M).

1. acide phtalimidopercaproïque

2. acide perdidécanoïque

3. acide perdinonanoïque

4. acide perdidodécanoïque

Peracids used:

1. phthalimidopercaproic acid

2. perdidecanoic acid

3. perdinonanoic acid

4. perdidodecanoic acid

5. chlorure de cétyl triméthyl ammonium

6. bromure de cétyl triméthyl ammonium

7. bromure de cétyl diméthyl hydroxyéthyl-2 ammonium

8. bromure de cétyl méthyl bis(hydroxyéthyl-2) ammonium

9. bromure de cétyl diaza-1,4 bicyclo(2.2.2) octyl ammonium Tensio-actif Peracide - 5 6 7 8 9 MPPM 5300 20 30 50 80 20 1 27500 100 100 150 270 60 2 3600 10 10 20 30 10 3 4100 20 20 40 30 10 4 10800 20 10 30 40 50

The surfactants used in combination with the above peracids are:

5. cetyl trimethyl ammonium chloride

6. cetyl trimethyl ammonium bromide

7. cetyl dimethyl hydroxyethyl-2-ammonium bromide

8. cetyl methyl bis (2-hydroxyethyl) ammonium bromide

9. cetyl diaza-1,4 bicyclo (2.2.2) octyl ammonium bromide Surfactant peracid - 5 6 7 8 9 MMPP 5300 20 30 50 80 20 1 27500 100 100 150 270 60 2 3600 10 10 20 30 10 3 4100 20 20 40 30 10 4 10800 20 10 30 40 50

These results show that the following composition the invention provides results equivalent to those obtained with magnesium monoperphthalate (MPPM) which is the best decontaminant currently known for Paraoxon. In addition, as shown in Example 2 below, the compositions of the invention are also effective against organosulfur compounds.

Example 2

peracid pH T _1/2 (s) MMPP 9 10 1 10.5 40 2 9.1 10 3 9.3 10 4 9.6 10

This example shows that the reaction is practically total in seconds. The comparison with MPPM puts highlight the effectiveness of cetyltrimethylammonium percarboxylate of the invention.

Claims (6)

1. Process for decontaminating materials contaminated with organophosphorus or organosulfur toxic agents, using a composition containing a peracid and a surfactant, characterized in that this composition comprises

   a peracid, or a salt thereof, chosen from

   an imido peracid represented by the general formula (I)

   

   in which n is an integer between 3 and 8, and R₁, which may be identical or different in each -CHR₁- group, is an alkyl group or a phenyl group, and

   phthalimidoperpropionic acid or phthalimidopercaproic acid, and

   a diperacid represented by the general formula (II) HO₃C - (CHR₂)_p - CO₃H in which p is an integer between 2 and 10 and R₂ has the same definition as R₁, and

   perdidecanoic acid, perdinonanoic acid and perdidodecanoic acid, and

   a quaternary ammonium type of cationic surfactant.
2. Process according to Claim 1, characterized in that the quaternary ammonium surfactant is represented by the general formula (III)

   

   in which R₁, R₂ and R₃, which may be identical or different, represent an alkyl or hydroxyalkyl group of 1 to 4 carbon atoms, R₄ represents a linear or branched alkyl group of 11 to 18 carbon atoms, and X represents a halogen or a hydroxyl radical.
3. Process according to Claim 2, characterized in that R₁, R₂ and R₃ represent a methyl group, an ethyl group or a hydroxyethyl group, R₄ represents a cetyl group and X is chlorine, bromine or an -OH radical.
4. Process according to Claim 3, characterized in that the surfactant of general formula (III) is chosen from cetyltrimethylammonium bromide or chloride, cetyldimethyl-2-hydroxyethylammonium bromide, cetylmethylbis(2-hydroxyethyl)ammonium bromide or cetyl-1,4-diazabicyclo[2.2.2]octylammonium bromide,
5. Process according to any one of the preceding claims, characterized in that the composition consists of an aqueous solution with a buffered pH of between 8 and 11.
6. Process according to any one of Claims 1 to 4, characterized in that the peracid and the surfactant are combined within the same molecule to form a tetraalkylammonium percarboxylate.