Pentachlorophenol

• PCP
• Penta

• 87-86-5
• 131-52-2 ( as sodium salt)

White, odorless, needle-shaped crystals

Fixed

1.98 g · cm -3

189 ° C.

309-310 ° C ( decomposition)

8 MPa (20 ° C)

4.7 (25 ° C)

• Sparingly soluble in water ( 14 mg · l-1 at 25 ° C)
• Soluble in many organic solvents

Risk

For carcinogenic substances no MAK value is generally assigned

Template: Infobox chemical / molecular formula search available

Pentachlorophenol, PCP short, is a chlorinated aromatic hydrocarbon, and represents a phenol derivative in which all of the aromatic hydrogen atoms are replaced by chlorine.

Representation

Pentachlorophenol can be prepared by chlorination of phenol, or by hydrolysis of hexachlorobenzene. The production of PCP was severely restricted due to the ecotoxicological properties.

Use

PCP was because of its fungicidal activity mainly in wood preservatives for use, for example in West Germany in wood preservatives Xylamon BV (in combination with lindane), in the GDR, among others in the media Hylotox IP and Paratectol 9025th In some countries, however, PCP is still used in the textile and leather industries as well as impregnating and blue stain for wood. Prove it is, inter alia, in textiles made of natural fibers and inks.

Properties

The 14 mg / l low (at 25 ° C) water solubility and low biodegradability lead to a ubiquitous occurrence. Since 1986, the production of pentachlorophenol in the Federal Republic of Germany is exposed. 1989 enacted the federal government pentachlorophenol Prohibition Order on the basis of the Chemicals Act. Since then, the manufacture, marketing and use of PCP, Na -PCP and PCP -containing products containing more than 5 mg / kg PCP prohibited. In 1996, the contents of the PCP regulation in force since chemicals Prohibition Ordinance (Section 15). Since the PIC Convention entered into force in 2004 and PCP should only be then exported to developing countries if they were informed about the potential for danger and have expressly agreed.

Biological effect

PCP uncouples the respiratory chain in the mitochondria of cells, which leads to increase in blood pressure, hyperglycemia, rapid breathing and heart failure. The picture is taken by both the gastrointestinal tract and on the skin. The biological half-life of PCP is approximately 1 to 3 weeks.

Proof

Pentachlorophenol can be detected by color reactions, more accurate determinations can be made by UV spectroscopy or thin-layer chromatography. A gas chromatographic analysis is performed mostly as methyl, ethyl ether or in acetylated form. The determination of PCP in wood after acetylation by GC- ECD ( electron capture detector ) is described in Annex IV (to § 6) to the Waste Wood Ordinance, the provision in leather in DIN EN ISO 17070th place of the electron capture detector (ECD) can also be a mass selective detector ( mass spectrometer, MS) be used.

UV spectroscopy is done by proof of Batho and hypochromic shift of the absorption, which occurs when PCP with a cyclodextrin - porphyrin complex ( " gedeckeltes cyclodextrin " ) interacts. The formation of hydrogen bonds between the hydroxyl group of the phenol and the nitrogen of the pyrrole leads to a change in the porphyrin absorbance.