Tetrachloroethylene

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Tetrachloroethylene
Tetrachloroethylene Tetrachloroethylene.svg
Tetrachloroethylene
Tetrachloroethylene Tetrachloroethylene-3D-vdW.png
Tetrachloroethylene
   Carbon, C
   Chlorine, Cl
Tetrakloroetilen2.jpg
Names
Preferred IUPAC name
Tetrachloroethene
Other names
Carbon bichloride; Carbon dichloride (Carboneum Dichloratum); Dicarbon tetrachloride; [1] Ethylene tetrachloride; Perchlor; Perchloroethene; Perchloroethylene; Chlorethose [2]
Identifiers
3D model (JSmol)
AbbreviationsPCE; Perc; Per
1304635
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.004.388 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 204-825-9
101142
KEGG
PubChem CID
RTECS number
  • KX3850000
UNII
UN number 1897
  • InChI=1S/C2Cl4/c3-1(4)2(5)6 Yes check.svgY
    Key: CYTYCFOTNPOANT-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C2Cl4/c3-1(4)2(5)6
    Key: CYTYCFOTNPOANT-UHFFFAOYAO
  • ClC(Cl)=C(Cl)Cl
Properties
C2Cl4
Molar mass 165.82 g/mol
AppearanceClear, very refractive, colorless liquid
Odor Mild, sharp and sweetish [3]
Density 1.622 g/cm3
Melting point −22.0 to −22.7 °C (−7.6 to −8.9 °F; 251.2 to 250.5 K)
Boiling point 121.1 °C (250.0 °F; 394.2 K)
0.15 g/L (25 °C)
Vapor pressure 14 mmHg (20 °C) [3]
−81.6·10−6 cm3/mol
1.505
Viscosity 0.89  cP at 25 °C
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Mild skin and respiratory irritant
GHS labelling:
GHS-pictogram-silhouette.svg GHS-pictogram-pollu.svg
Warning
H351, H411
P201, P202, P273, P281, P308+P313, P391, P405, P501
NFPA 704 (fire diamond)
[4]
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
2
0
0
Flash point Not flammable
Lethal dose or concentration (LD, LC):
3420 mg/kg (oral, rat) [5]
2629 mg/kg (oral, rat), >10000 mg/kg (dermal, rat) [6]
4000 ppm (rat, 4 hr)
5200 ppm (mouse, 4 hr)
4964 ppm (rat, 8 hr) [7]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 100 ppm
C 200 ppm (for 5 minutes in any 3-hour period), with a maximum peak of 300 ppm [3]
REL (Recommended)
Ca Minimize workplace exposure concentrations. [3]
IDLH (Immediate danger)
Ca [150 ppm] [3]
Safety data sheet (SDS) External MSDS
Related compounds
Related analogous organohalides
Tetrafluoroethylene
Tetrabromoethylene
Tetraiodoethylene
Related compounds
 Trichloroethylene
Dichloroethylene
1,1,2,2-Tetrachloroethane
Carbon tetrachloride
Supplementary data page
Tetrachloroethylene (data page)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Tetrachloroethylene, also known under the systematic name tetrachloroethene, or perchloroethylene, [lower-alpha 1] and abbreviations such as "perc" (or "PERC"), and "PCE", is a chlorocarbon with the formula Cl2C=CCl2. It is a colorless liquid widely used for dry cleaning of fabrics, hence it is sometimes called "dry-cleaning fluid". It also has its uses as an effective automotive brake cleaner. It has a mild sweet, sharp odor, detectable by most people at a concentration of 50 ppm. [8]

History and production

French chemist Henri Victor Regnault first synthesized tetrachloroethylene in 1839 by thermal decomposition of hexachloroethane following Michael Faraday's 1820 synthesis of protochloride of carbon (carbon tetrachloride).

C2Cl6 → C2Cl4 + Cl2

Faraday was previously falsely credited for the synthesis of tetrachloroethylene, which in reality, was carbon tetrachloride. While trying to make Faraday's "protochloride of carbon", Regnault found that his compound was different from Faraday's. Victor Regnault stated "According to Faraday, the chloride of carbon boiled around 70 °C (158 °F) to 77 °C (171 °F) degrees Celsius but mine did not begin to boil until 120 °C (248 °F) ". [9]

A few years after its discovery, in the 1840s, Tetrachloroethylene was named Chlorethose by Auguste Laurent. The -ose ending was explained as the fourfold replacement of the hydrogens in ethylene. If only one atom of hydrogen was replaced, the word would end with -ase. By Laurent's logic, vinyl chloride would be named Chlorethase. [10]

Tetrachloroethylene can be made by passing chloroform vapour through a red-hot tube, the side products include hexachlorobenzene and hexachloroethane, as reported in 1886. [11]

Most tetrachloroethylene is produced by high-temperature chlorinolysis of light hydrocarbons. The method is related to Faraday's method since hexachloroethane is generated and thermally decomposes. [12] Side products include carbon tetrachloride, hydrogen chloride, and hexachlorobutadiene.

Several other methods have been developed. When 1,2-dichloroethane is heated to 400 °C with chlorine, tetrachloroethylene is produced by the chemical reaction:

ClCH2CH2Cl + 3 Cl2 → Cl2C=CCl2 + 4 HCl

This reaction can be catalyzed by a mixture of potassium chloride and aluminium chloride or by activated carbon. Trichloroethylene is a major byproduct, which is separated by distillation.

Worldwide production was about 1 million metric tons (980,000 long tons; 1,100,000 short tons) in 1985. [12]

Although in very small amounts, tetrachloroethylene occurs naturally in volcanoes along with trichloroethylene. [13]

Uses

Advertisement for Dow Chemical's Tetrachloroethylene, 1952 You Can Cut Operating Costs with Dow-PER - DPLA - ee749e230034a7ce59dde05b9dfc5fcc.jpg
Advertisement for Dow Chemical's Tetrachloroethylene, 1952

Tetrachloroethylene is an excellent nonpolar solvent for organic materials. Otherwise, it is volatile, highly stable and nonflammable, and has low toxicity. For these reasons, it has been widely used in dry cleaning worldwide since the 1930s. The chemist Sylvia Stoesser (1901–1991) suggested Tetrachloroethylene to be used in dry cleaning as an alternative to highly flammable dry cleaning solvents such as naphtha. [14]

It is also used to degrease metal parts in the automotive and other metalworking industries, usually as a mixture with other chlorocarbons. It appears in a few consumer products including paint strippers, aerosol preparations and spot removers.

Historical applications

Tetrachloroethylene was once extensively used as an intermediate in the manufacture of HFC-134a and related refrigerants. In the early 20th century, tetrachloroethene was used for the treatment of hookworm infestation. [15] [16]

Health and safety

Tetrachloroethylene is much less toxic than other chlorinated solvents. [8] The acute and chronic toxicity of tetrachloroethylene is moderate to low. Reports of human injury are uncommon despite its wide usage in dry cleaning and degreasing. [17]

Despite the advantages of tetrachloroethylene, many[ who? ] have called for its replacement from widespread commercial use. It has been described as a possible "neurotoxicant, liver and kidney toxicant and reproductive and developmental toxicant (...) a 'potential occupational carcinogen'". [18] [ better source needed ]

As an anthelmintic, tetrachloroethylene was given orally to approximately fifty thousand people between 1925 and 1943. The most severe side effects were nausea and vomiting due to the irritation of gastric tract. Most reported poisonings were manifestations of its narcotic effects. [19]

Metabolism

Tetrachloroethylene's biological half-life is approximately 3 days. [20] About 98% of the inhaled Tetrachloroethylene is exhaled unchanged and only about 1–3% is metabolised to tetrachloroethylene oxide which rapidly isomerises into trichloroacetyl chloride. Trichloroacetyl chloride hydrolyses to trichloroacetic acid. [21] [20]

Carcinogenicity

Tetrachloroethylene has been classified as "probably carcinogenic to humans" (Group 2A) by the International Agency for Research on Cancer (IARC). There is a possibility that it is carcinogenic to humans in long-term exposure, but the evidence is limited since most of the evaluated dry-cleaners had heavy smoking and drinking habits which are known to cause multiple types of cancer. [22] Epidemiological research has been conducted in the dry-cleaning industry because of the widespread use of tetrachloroethylene in the industry since 1960. The evidence demonstrates a positive association between tetrachloroethylene exposure, bladder cancer, non-Hodgkin lymphoma, and multiple myeloma in adults. A review of 109 occupational studies estimated a mean exposure of 59 ppm in dry-cleaning employees. Epidemiological evidence shows that exposure via ingestion or inhalation can increase tumor incidence. [23] Exposure to tetrachloroethylene in a typical dry cleaning shop is considered far below the levels required to cause any risk. [24]

Testing for exposure

Tetrachloroethylene exposure can be evaluated by a breath test, analogous to breath-alcohol measurements. Also, for acute exposures, tetrachloroethylene in expired air can be measured. [25] Tetrachloroethylene can be detected in the breath for weeks following a heavy exposure. Tetrachloroethylene and its metabolite trichloroacetic acid, can be detected in the blood.

In Europe, the Scientific Committee on Occupational Exposure Limits (SCOEL) recommends for tetrachloroethylene an occupational exposure limit (8-hour time-weighted average) of 20 ppm and a short-term exposure limit (15 min) of 40 ppm. [26]

Remediation and degradation

In principle, tetrachloroethylene contamination can be remediated by chemical treatment. Chemical treatment involves reducing metals such as iron powder.

Bioremediation usually entails reductive dechlorination under anaerobic conditions by Dehalococcoides spp. [27] Under aerobic conditions, degradation may occur via cometabolism by Pseudomonas sp. [28] Products of biological reductive dechlorination include trichloroethene, cis-1,2-dichloroethene, vinyl chloride, ethene and chloride.

Explanatory notes

  1. ↑ Also spelt as perchlorethylene, especially in older texts.

Related Research Articles

<span class="mw-page-title-main">Dry cleaning</span> Cleaning of fabrics in non-aqueous solvents

Dry cleaning is any cleaning process for clothing and textiles using a solvent other than water.

<span class="mw-page-title-main">Carbon tetrachloride</span> Chemical compound

Carbon tetrachloride, also known by many other names (such as carbon tet for short and tetrachloromethane, also recognised by the IUPAC) is a chemical compound with the chemical formula CCl4. It is a non-flammable, dense, colourless liquid with a "sweet" chloroform-like odour that can be detected at low levels. It was formerly widely used in fire extinguishers, as a precursor to refrigerants and as a cleaning agent, but has since been phased out because of environmental and safety concerns. Exposure to high concentrations of carbon tetrachloride can affect the central nervous system and degenerate the liver and kidneys. Prolonged exposure can be fatal.

<span class="mw-page-title-main">Dichloromethane</span> Chemical compound

Dichloromethane is an organochlorine compound with the formula CH2Cl2. This colorless, volatile liquid with a chloroform-like, sweet odor is widely used as a solvent. Although it is not miscible with water, it is slightly polar, and miscible with many organic solvents.

<span class="mw-page-title-main">Vinyl chloride</span> Chemical compound

Vinyl chloride is an organochloride with the formula H2C=CHCl. It is also called vinyl chloride monomer (VCM) or chloroethene. This colorless compound is an important industrial chemical chiefly used to produce the polymer, poly(vinyl chloride) (PVC). Vinyl chloride monomer is among the top twenty largest petrochemicals (petroleum-derived chemicals) in world production. The United States remains the largest vinyl chloride manufacturing region because of its low-production-cost position in chlorine and ethylene raw materials. China is also a large manufacturer and one of the largest consumers of vinyl chloride. Vinyl chloride is a flammable gas that has a sweet odor and is carcinogenic. It can be formed in the environment when soil organisms break down chlorinated solvents. Vinyl chloride that is released by industries or formed by the breakdown of other chlorinated chemicals can enter the air and drinking water supplies. Vinyl chloride is a common contaminant found near landfills. Before the 1970s, vinyl chloride was used as an aerosol propellant and refrigerant.

<span class="mw-page-title-main">1,1,1-Trichloroethane</span> Solvent, now banned for ozone depletion

The organic compound 1,1,1-trichloroethane, also known as methyl chloroform and chlorothene, is a chloroalkane with the chemical formula CH3CCl3. It is an isomer of 1,1,2-trichloroethane. This colorless, sweet-smelling liquid was once produced industrially in large quantities for use as a solvent. It is regulated by the Montreal Protocol as an ozone-depleting substance and its use is being rapidly phased out.

<span class="mw-page-title-main">Trichloroethylene</span> C2HCl3, widely used industrial solvent

Trichloroethylene (TCE) is a halocarbon with the formula C2HCl3, commonly used as an industrial degreasing solvent. It is a clear, colourless, non-flammable, volatile liquid with a chloroform-like pleasant mild smell and sweet taste. Its IUPAC name is trichloroethene. Trichloroethylene has been sold under a variety of trade names. Industrial abbreviations include TCE, trichlor, Trike, Tricky and tri. Under the trade names Trimar and Trilene, it was used as a volatile anesthetic and as an inhaled obstetrical analgesic. It should not be confused with the similar 1,1,1-trichloroethane, which is commonly known as chlorothene.

In organochlorine chemistry, reductive dechlorination describes any chemical reaction which cleaves the covalent bond between carbon and chlorine via reductants, to release chloride ions. Many modalities have been implemented, depending on the application. Reductive dechlorination is often applied to remediation of chlorinated pesticides or dry cleaning solvents. It is also used occasionally in the synthesis of organic compounds, e.g. as pharmaceuticals.

Halocarbon compounds are chemical compounds in which one or more carbon atoms are linked by covalent bonds with one or more halogen atoms resulting in the formation of organofluorine compounds, organochlorine compounds, organobromine compounds, and organoiodine compounds. Chlorine halocarbons are the most common and are called organochlorides.

<span class="mw-page-title-main">Chlorobenzene</span> Aromatic organochlorine compound

Chlorobenzene (abbreviated PhCl) is an aryl chloride and the simplest of the chlorobenzenes, consisting of a benzene ring substituted with one chlorine atom. Its chemical formula is C6H5Cl. This colorless, flammable liquid is a common solvent and a widely used intermediate in the manufacture of other chemicals.

<span class="mw-page-title-main">Hexachloroethane</span> Chemical compound

Hexachloroethane (perchloroethane) is an organochlorine compound with the chemical formula (CCl3)2. It is a white or colorless solid at room temperature with a camphor-like odor. It has been used by the military in smoke compositions, such as base-eject smoke munitions.

Jig-A-Loo is a silicone-based lubricant and water-repellent spray. The manufacturer states that it contains no oil, grease, wax, petroleum distillates or detergent and that it doesn't stain or smell after application. It is indicated for use on wood, metal, glass, rubber, leather, fabrics and most plastics. It has been used in the commercial and industrial sectors in Canada since 1958, and was launched in 1998 to the Canadian mass retail market, and globally in 2007.

<span class="mw-page-title-main">1,1,2,2-Tetrachloroethane</span> Chemical compound

1,1,2,2-tetrachloroethane (TeCA), also known by the brand names Bonoform, Cellon and Westron, is an organic compound. It is colorless liquid and has a sweet odor. It is used as an industrial solvent and as a separation agent. TeCA is toxic and it can be inhaled, consumed or absorbed through the skin. After exposure, nausea, dizziness or even liver damage may occur.

<span class="mw-page-title-main">1-Bromopropane</span> Chemical compound

1-Bromopropane (n-propylbromide or nPB) is an organobromine compound with the chemical formula CH3CH2CH2Br. It is a colorless liquid that is used as a solvent. It has a characteristic hydrocarbon odor. Its industrial applications increased dramatically in the 21st century due to the phasing out of chloro­fluoro­carbons and chloro­alkanes such as 1,1,1-Trichloro­ethane under the Montreal Protocol.

<span class="mw-page-title-main">Hexachlorobutadiene</span> Chemical compound

Hexachlorobutadiene, (often abbreviated as "HCBD") Cl2C=C(Cl)C(Cl)=CCl2, is a colorless liquid at room temperature that has an odor similar to that of turpentine. It is a chlorinated aliphatic diene with niche applications but is most commonly used as a solvent for other chlorine-containing compounds. Structurally, it has a 1,3-butadiene core, but fully substituted with chlorine atoms.

1,1,2-Trichloro-1,2,2-trifluoroethane, also called trichlorotrifluoroethane or CFC-113, is a chlorofluorocarbon. It has the formula Cl2FC−CClF2. This colorless, volatile liquid is a versatile solvent.

<span class="mw-page-title-main">Chloroacetaldehyde</span> Chemical compound

Chloroacetaldehyde is an organic compound with the formula ClCH2CHO. Like some related compounds, it is highly electrophilic reagent and a potentially dangerous alkylating agent. The compound is not normally encountered in the anhydrous form, but rather as the hemiacetal (ClCH2CH(OH))2O.

<span class="mw-page-title-main">Perchloromethyl mercaptan</span> Chemical compound

Perchloromethyl mercaptan is the organosulfur compound with the formula CCl3SCl. It is mainly used as an intermediate for the synthesis of dyes and fungicides (captan, folpet). It is a colorless oil, although commercial samples are yellowish. It is insoluble in water but soluble in organic solvents. It has a foul, unbearable, acrid odor. Perchloromethyl mercaptan is the original name. The systematic name is trichloromethanesulfenyl chloride, because the compound is a sulfenyl chloride, not a mercaptan.

<span class="mw-page-title-main">Pentachloroethane</span> Chemical compound

Pentachloroethane is a chemical compound of chlorine, hydrogen, and carbon with the chemical formula C2HCl5. It is a colourless non-flammable liquid that is used as a solvent for oil and grease, in metal cleaning, and in the separation of coal from impurities.

<span class="mw-page-title-main">Brake cleaner</span>

Brake cleaner, often also called parts cleaner, is a mostly colorless cleaning agent, mainly used for cleaning the brake disks, the engine compartment and underfloor of motor vehicles. An important feature is that the brake cleaner leaves no residue after the solvents evaporate.

References

  1. ↑ C. Chabrie "General Method for the Preparation of Carbon Fluorides" in Journal - Chemical Society, London. (1890). UK: Chemical Society.
  2. ↑ Justus Liebigs Annalen der Chemie. (1845). Germany: Verlag Chemie. Page 277
  3. 1 2 3 4 5 NIOSH Pocket Guide to Chemical Hazards. "#0599". National Institute for Occupational Safety and Health (NIOSH).
  4. ↑ "Compound Summary: Tetrachloroethylene". PubChem . Retrieved 9 September 2020.
  5. ↑ Sigma Aldrich Tetrachloroethylene MSDS
  6. ↑ Fischer Scientific Tetrachloroethylene MSDS
  7. ↑ "Tetrachloroethylene". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  8. 1 2 Ethel Browning, Toxicity of Industrial Organic Solvents (1953, [ https://archive.org/details/cftri.3112toxicityofindust0000ethe/page/182/mode/1up pages 182-185]
  9. ↑ V. Regnault (1839) "Sur les chlorures de carbone CCl et CCl2" (On the chlorides of carbon CCl and CCl2 ), Annales de Chimie et de Physique, vol. 70, pages 104-107. Reprinted in German as: V. Regnault (1839). "Ueber die Chlorverbindungen des Kohlenstoffs, C2Cl2 und CCl2". Annalen der Pharmacie. 30 (3): 350–352. doi:10.1002/jlac.18390300310.
  10. ↑ Transactions of the Pharmaceutical Meetings. (1847). UK: J. Churchill. page 548
  11. ↑ W. Ramsay and S. Young, Jahresberichte, 1886, p. 628
  12. 1 2 M. Rossberg et al. "Chlorinated Hydrocarbons" in Ullmann's Encyclopedia of Industrial Chemistry, 2006, Wiley-VCH, Weinheim. doi : 10.1002/14356007.a06_233.pub2
  13. ↑ Gribble, G. W. (1996). "Naturally occurring organohalogen compounds – A comprehensive survey". Progress in the Chemistry of Organic Natural Products. 68 (10): 1–423. doi:10.1021/np50088a001. PMID   8795309.
  14. ↑ Amos, J. Lawrence (1990). "Chlorinated solvents". In Boundy, Ray H.; Amos, J. Lawrence (eds.). A History of the Dow Chemical Physics Lab : the freedom to be creative. New York and Basel: Marcel Dekker, Inc. pp. 71–79.
  15. ↑ Young, M.D.; et al. (1960). "The Comparative Efficacy of Bephenium Hydroxynaphthoate and Tetrachloroethylene against Hookworm and other Parasites of Man". American Journal of Tropical Medicine and Hygiene. 9 (5): 488–491. doi:10.4269/ajtmh.1960.9.488. PMID   13787477.
  16. ↑ "Clinical Aspects and Treatment of the More Common Intestinal Parasites of Man (TB-33)". Veterans Administration Technical Bulletin 1946 & 1947. 10: 1–14. 1948.
  17. ↑ E.-L. Dreher; T. R. Torkelson; K. K. Beutel (2011). "Chlorethanes and Chloroethylenes". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.o06_o01. ISBN   978-3527306732.
  18. ↑ Ceballos, Diana M.; Fellows, Katie M.; Evans, Ashley E.; Janulewicz, Patricia A.; Lee, Eun Gyung; Whittaker, Stephen G. (2021). "Perchloroethylene and Dry Cleaning: It's Time to Move the Industry to Safer Alternatives". Frontiers in Public Health. 9: 638082. doi: 10.3389/fpubh.2021.638082 . PMC   7973082 . PMID   33748070.
  19. ↑ Ellen B. Foot, Virginia Apgar and Kingsley Bishop, [https://archive.org/details/sim_anesthesiology_1943-05_4_3/page/283/mode/1up Tetrachlorethylene as an Anesthetic Agent], in Anesthesiology, 1943-05: Vol 4 Iss 3
  20. 1 2 Biological Monitoring: An Introduction. (1993). page 470
  21. ↑ Toxicological Profile for Tetrachloroethylene: Draft. (1995). U.S. Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry.
  22. ↑ "Tetrachloroethylene (IARC Summary & Evaluation, Volume 63, 1995)". www.inchem.org.
  23. ↑ Guyton, KZ; Hogan, KA; Scott, CS; et al. (14 February 2014). "Human health effects of tetrachloroethylene: key findings and scientific issues". Environ Health Perspect. 122 (4): 325–334. doi:10.1289/ehp.130735. PMID   24531164 – via PubMed.
  24. ↑ Azimi Pirsaraei, S. R.; Khavanin, A; Asilian, H; Soleimanian, A (2009). "Occupational exposure to perchloroethylene in dry-cleaning shops in Tehran, Iran". Industrial Health. 47 (2): 155–9. doi: 10.2486/indhealth.47.155 . PMID   19367044.
  25. ↑ "Tetrachloroethylene Toxicity: Section 3.1. Evaluation and Diagnosis | Environmental Medicine | ATSDR". www.atsdr.cdc.gov. 9 February 2021. Retrieved 2 March 2023.
  26. ↑ "SCOEL recommendations". 22 April 2011. Retrieved 22 April 2011.
  27. ↑ Ghattas, Ann-Kathrin; Fischer, Ferdinand; Wick, Arne; Ternes, Thomas A. (2017). "Anaerobic biodegradation of (Emerging) organic contaminants in the aquatic environment". Water Research. 116: 268–295. Bibcode:2017WatRe.116..268G. doi: 10.1016/j.watres.2017.02.001 . PMID   28347952.
  28. ↑ Ryoo, D.; Shim, H.; Arenghi, F. L. G.; Barbieri, P.; Wood, T. K. (2001). "Tetrachloroethylene, Trichloroethylene, and Chlorinated Phenols Induce Toluene-o-xylene Monooxoygenase Activity in Pseudomonas stutzeri OX1". Appl Microbiol Biotechnol. 56 (3–4): 545–549. doi:10.1007/s002530100675. PMID   11549035. S2CID   23770815.

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