वाष्पशील कार्बनिक यौगिक

मुक्त ज्ञानकोश विकिपीडिया से

वाष्पशील कार्बनिक यौगिक(Volatile organic compounds) या

(VOCs) वे कार्बनिक रसायन है जिनमे कमरे के समान्य ताप पर भी उच्च वाष्प दाब होता है। इनका उच्च वाष्प दाब, उनके कम क्वथनांक की वजह से garmi अधिक अणुओं के ठोस या द्रव वाष्पीकृत या ऊर्ध्वपतित होकर यौगिक बनाने व आस पास की वायु में मिलने के कारण होता है। निम्न क्वथनांक के कारण इनमे उच्च वाष्प दाब होता है, अधिक अणुओ का जल या ठोस अवस्था से वाष्पीकरण या ऊर्ध्वपातन होता है तथा यौगिक बनकर वायुमंडल में मिश्रित हो जाता है। जैसे कि निम्न क्वथनांक के paint- 19 °C (–2 °F) से formaldehyde का वाष्पीकरण।

VOCs, कई अलग अलग, और सर्वव्यापी हैं। इनमे दोनों मानव निर्मित और स्वाभाविक रूप से होने वाली रासायनिक यौगिक शामिल है। अधिकतर सुगंधिया VOCs है। VOCs पौधों के मध्य सम्प्रेषण में महत्वपूर्ण भूमिका निभाते हैं,[1] तथा पौधों से जीवो को संदेश भेजते हैं। कुछ VOCs मानव स्वास्थ्य के लिए खतरनाक होते हैं व वातावरण को हानी पहुंचाते हैं। Anthropogenic VOCs are regulated by law, especially indoors, where concentrations are the highest. Harmful VOCs typically are not acutely toxic, but have compounding long-term health effects. Because the concentrations are usually low and the symptoms slow to develop, research into VOCs and their effects is difficult.

Definitions[संपादित करें]

Diverse definitions of the term VOC[2] are in use.

The definitions of VOCs used for control of precursors of photochemical smog used by the EPA, and states in the US with independent outdoor air pollution regulations include exemptions for VOCs that are determined to be non-reactive, or of low-reactivity in the smog formation process. EPA formerly defined these compounds as reactive organic gases (ROG) but changed the terminology to VOC.[उद्धरण चाहिए]

In the USA, different regulations vary between states - most prominent is the VOC regulation by SCAQMD and by the California Air Resources Board.[3] However, this specific use of the term VOCs can be misleading, especially when applied to indoor air quality because many chemicals that are not regulated as outdoor air pollution can still be important for indoor air pollution.

Canada[संपादित करें]

Health Canada classes VOCs as organic compounds that have boiling points roughly in the range of 50 से 250 °से. (122 से 482 °फ़ै). The emphasis is placed on commonly encountered VOCs that would have an effect on air quality.[4]

European Union[संपादित करें]

A VOC is any organic compound having an initial boiling point less than or equal to 250 °से. (482 °फ़ै) measured at a standard atmospheric pressure of 101.3 kPa[5]

US[संपादित करें]

VOCs (or specific subsets of the VOCs) are legally defined in the various laws and codes under which they are regulated. Other definitions may be found from government agencies investigating or advising about VOCs.[6] The United States Environmental Protection Agency (EPA) regulates VOCs in the air, water, and land. The Safe Drinking Water Act implementation includes a list labeled "VOCs in connection with contaminants that are organic and volatile."[7] The EPA also publishes testing methods for chemical compounds, some of which refer to VOCs.[8]

In addition to drinking water, VOCs are regulated in discharges to waters (sewage treatment and stormwater disposal), as hazardous waste,[9] but not in non industrial indoor air.[10] The United States Department of Labor and its Occupational Safety and Health Administration (OSHA) regulate VOC exposure in the workplace. Volatile organic compounds that are hazardous material would be regulated by the Pipeline and Hazardous Materials Safety Administration while being transported.

Biologically generated VOCs[संपादित करें]

Not counting methane, biological sources emit an estimated 1150 teragrams of carbon per year in the form of VOCs.[11] The majority of VOCs are produced by plants, the main compound being isoprene. The remainder are produced by animals, microbes, and fungi, such as molds.

The strong odor emitted by many plants consists of green leaf volatiles, a subset of VOCs. Emissions are affected by a variety of factors, such as temperature, which determines rates of volatilization and growth, and sunlight, which determines rates of biosynthesis. Emission occurs almost exclusively from the leaves, the stomata in particular. A major class of VOCs is terpenes, such as myrcene.[12] Providing a sense of scale, a forest 62,000 km2 in area (the U.S. state of Pennsylvania) is estimated to emit 3,400,000 kilograms of terpenes on a typical August day during the growing season.[13] VOCs should be a factor in choosing which trees to plant in urban areas.[14] Induction of genes producing volatile organic compounds, and subsequent increase in volatile terpenes has been achieved in maize using (Z)-3-Hexen-1-ol and other plant hormones.[15]

Anthropogenic sources[संपादित करें]

Anthropogenic sources emit about 142 teragrams of carbon per year in the form of VOCs.[11]

Specific components[संपादित करें]

Paints and coatings[संपादित करें]

A major source of man-made VOCs are coatings, especially paints and protective coatings. Solvents are required to spread a protective or decorative film. Approximately 12 billion litres of paints are produced annually. Typical solvents are aliphatic hydrocarbons, ethyl acetate, glycol ethers, and acetone. Motivated by cost, environmental concerns, and regulation, the paint and coating industries are increasingly shifting toward aqueous solvents.[16]

Chlorofluorocarbons and chlorocarbons[संपादित करें]

Chlorofluorocarbons, which are banned or highly regulated, were widely used cleaning products and refrigerants. Tetrachloroethene is used widely in dry cleaning and by industry.

Fossil fuels[संपादित करें]

The use of fossil fuels produces VOCs either directly as products (e.g., gasoline) or indirectly as byproducts (e.g., automobile exhaust gas).[उद्धरण चाहिए]

Benzene[संपादित करें]

One VOC that is a known human carcinogen is benzene, which is a chemical found in environmental tobacco smoke, stored fuels, and exhaust from cars. Benzene also has natural sources such as volcanoes and forest fires. It is frequently used to make other chemicals in the production of plastics, resins, and synthetic fibers. Benzene evaporates into the air quickly and the vapor of benzene is heavier than air allowing the compound to sink into low-lying areas. Benzene has also been known to contaminate food and water and if digested can lead to vomiting, dizziness, sleepiness, rapid heartbeat, and at high levels, even death may occur.[उद्धरण चाहिए]

Methylene chloride[संपादित करें]

Methylene chloride is another VOC that is highly dangerous to human health. It can be found in adhesive removers and aerosol spray paints and the chemical has been proven to cause cancer in animals. In the human body, methylene chloride is converted to carbon monoxide and a person will suffer the same symptoms as exposure to carbon monoxide. If a product that contains methylene chloride needs to be used the best way to protect human health is to use the product outdoors. If it must be used indoors, proper ventilation is essential to keeping exposure levels down.[उद्धरण चाहिए]

Perchloroethylene[संपादित करें]

Perchloroethylene is a volatile organic compound that has been linked to causing cancer in animals. It is also suspected to cause many of the breathing related symptoms of exposure to VOCs.[उद्धरण चाहिए] Perchloroethylene is used mostly in dry cleaning. While dry cleaners recapture perchloroethylene in the dry cleaning process to reuse it, some environmental release is unavoidable. Studies show that people breathe in low levels of this VOC in homes where dry-cleaned clothes are stored and while wearing dry-cleaned clothing.[उद्धरण चाहिए]

MTBE[संपादित करें]

MTBE was banned in the US around 2004 in order to limit further contamination of drinking water aquifers (groundwater) primarily from leaking underground gasoline storage tanks where MTBE was used as an octane booster and oxygenated-additive.[उद्धरण चाहिए]

Indoor air[संपादित करें]

Since many people spend much of their time indoors, long-term exposure to VOCs in the indoor environment can contribute to sick building syndrome.[17] In offices, VOC results from new furnishings, wall coverings, and office equipment such as photocopy machines, which can off-gas VOCs into the air.[18][19] Good ventilation and air-conditioning systems are helpful at reducing VOCs in the indoor environment.[18] Studies also show that relative leukemia and lymphoma can increase through prolonged exposure of VOCs in the indoor environment.[20]

In the United States, there are two standardized methods for measuring VOCs, one by the National Institute for Occupational Safety and Health (NIOSH) and another by Occupational Safety and Health Administration (OSHA). Each method uses a single component solvent; butanol and hexane cannot be sampled, however, on the same sample matrix using the NIOSH or OSHA method.[21]

The aromatic VOC compound benzene, emitted from exhaled cigarette smoke is labeled as carcinogenic, and is ten times higher in smokers than in nonsmokers.[18]

The United States Environmental Protection Agency (EPA) has found concentrations of VOCs in indoor air to be 2 to 5 times greater than in outdoor air and sometimes far greater. During certain activities indoor levels of VOCs may reach 1,000 times that of the outside air.[22] Studies have shown that individual VOC emissions by themselves are not that high in an indoor environment, but the indoor total VOC (TVOC) concentrations can be up to five times higher than the VOC outdoor levels.[23] New buildings especially, contribute to the highest level of VOC off-gassing in an indoor environment because of the abundant new materials generating VOC particles at the same time in such a short time period.[17] In addition to new buildings, we also use many consumer products that emit VOC compounds, therefore the total concentration of VOC levels is much greater within the indoor environment.[17]

VOC concentration in an indoor environment during winter is three to four times higher than the VOC concentrations during the summer.[24] High indoor VOC levels are attributed to the low rates of air exchange between the indoor and outdoor environment as a result of tight-shut windows and the increasing use of humidifiers.[25]

Regulation of indoor VOC emissions[संपादित करें]

In most countries, a separate definition of VOCs is used with regard to indoor air quality that comprises each organic chemical compound that can be measured as follows: Adsorption from air on Tenax TA, thermal desorption, gas chromatographic separation over a 100% nonpolar column (dimethylpolysiloxane). VOC (volatile organic compounds) are all compounds that appear in the gas chromatogram between and including n-hexane and n-hexadecane. Compounds appearing earlier are called VVOC (very volatile organic compounds) compounds appearing later are called SVOC (semi-volatile organic compounds). See also these standards: ISO 16000-6, ISO 13999-2, VDI 4300-6, German AgBB evaluating scheme, German DIBt approval scheme, GEV testing method for the EMICODE. Some overviews over VOC emissions rating schemes[26] have been collected and compared.

France, Germany and Belgium have enacted regulations to limit VOC emissions from commercial products, and industry has developed numerous voluntary ecolabels and rating systems, such as EMICODE,[27] M1,[28] Blue Angel[29] and Indoor Air Comfort[30] In the United States, several standards exist; California Standard CDPH Section 01350[31] is the most popular one. Over the last few decades, these regulations and standards changed the marketplace, leading to an increasing number of low-emitting products: The leading voluntary labels report that licenses to several hundreds of low-emitting products have been issued (see the respective webpages such as MAS Certified Green.- Certified Products[32]).

Formaldehyde[संपादित करें]

Many building materials such as paints, adhesives, wall boards, and ceiling tiles slowly emit formaldehyde, which irritates the mucous membranes and can make a person irritated and uncomfortable.[18] Formaldehyde emissions from wood are in the range of 0.02 – 0.04 ppm. Relative humidity within an indoor environment can also affect the emissions of formaldehyde. High relative humidity and high temperatures allow more vaporization of formaldehyde from wood-materials.[33]

Health risks[संपादित करें]

Respiratory, allergic, or immune effects in infants or children are associated with man-made VOCs and other indoor or outdoor air pollutants.[34]

Some VOCs, such as styrene and limonene, can react with nitrogen oxides or with ozone to produce new oxidation products and secondary aerosols, which can cause sensory irritation symptoms.[18][35] Unspecified VOCs are important in the creation of smog.[36]

Health effects include eye, nose, and throat irritation; headaches, loss of coordination, nausea; damage to liver, kidney, and central nervous system. Some organics can cause cancer in animals; some are suspected or known to cause cancer in humans. Key signs or symptoms associated with exposure to VOCs include conjunctival irritation, nose and throat discomfort, headache, allergic skin reaction, dyspnea, declines in serum cholinesterase levels, nausea, vomiting, nose bleeding, fatigue, dizziness.[उद्धरण चाहिए]

The ability of organic chemicals to cause health effects varies greatly from those that are highly toxic, to those with no known health effects. As with other pollutants, the extent and nature of the health effect will depend on many factors including level of exposure and length of time exposed. Eye and respiratory tract irritation, headaches, dizziness, visual disorders, and memory impairment are among the immediate symptoms that some people have experienced soon after exposure to some organics. At present, not much is known about what health effects occur from the levels of organics usually found in homes. Many organic compounds are known to cause cancer in animals; some are suspected of causing, or are known to cause, cancer in humans.[37]

Reducing exposure[संपादित करें]

To reduce exposure to these toxins, one should buy products that contain Low-VOCs or No VOCs. Only the quantity which will soon be needed should be purchased, eliminating stockpiling of these chemicals. Use products with VOCs in well ventilated areas. When designing homes and buildings, design teams can implement the best possible ventilation plans, call for the best mechanical systems available, and design assemblies to reduce the amount of infiltration into the building. These methods will help improve indoor air quality, but by themselves they cannot keep a building from becoming an unhealthy place to breathe.[उद्धरण चाहिए]

Limit values for VOC emissions[संपादित करें]

Limit values for VOC emissions into indoor air are published by e.g. AgBB, AFSSET, California Department of Public Health, and others. These regulations have prompted several companies to adapt with VOC level reductions in products that have VOCs in their formula, such Benjamin Moore & Co. in the paint industry and Weld-On in the adhesive industry.[उद्धरण चाहिए]

Chemical fingerprinting[संपादित करें]

The exhaled human breath contains a few hundred volatile organic compounds and is used in breath analysis to serve as a VOC biomarker to test for diseases such as lung cancer.[38] One study has shown that "volatile organic compounds ... are mainly blood borne and therefore enable monitoring of different processes in the body."[39] And it appears that VOC compounds in the body "may be either produced by metabolic processes or inhaled/absorbed from exogenous sources" such as environmental tobacco smoke.[38][40] Research is still in the process to determine whether VOCs in the body are contributed by cellular processes or by the cancerous tumors in the lung or other organs.

VOC sensors[संपादित करें]

VOCs in the environment or certain atmospheres can be detected based on different principles and interactions between the organic compounds and the sensor components. There are electronic devices that can detect ppm concentrations despite the non-selectivity. Others can predict with reasonable accuracy the molecular structure of the volatile organic compounds in the environment or enclosed atmospheres[41] and could be used as accurate monitors of the Chemical Fingerprint and further as health monitoring devices.

Solid-phase microextraction (SPME) techniques are used to collect VOCs at low concentrations for analysis.[42]

Direct injection mass spectrometry techniques are frequently utilized for the rapid detection and accurate quantification of VOCs.[43] PTR-MS is among the methods that have been used most extensively for the on-line analysis of biogenic and antropogenic VOCs.[44] Recent PTR-MS instruments based on time-of-flight mass spectrometry have been reported to reach detection limits of 20 pptv after 100 ms and 750 ppqv after 1 min measurement (signal integration) time. The mass resolution of these devices is between 7000 and 10,500 m/Δm, thus it is possible to separate most common isobaric VOCs and quantify them independently.[45]

See also[संपादित करें]

References[संपादित करें]

  1. "Plants: A Different Perspective". Content.yudu.com. मूल से 17 फ़रवरी 2017 को पुरालेखित. अभिगमन तिथि 2012-07-03.
  2. "What does VOC mean?". Eurofins.com. मूल से 30 मई 2012 को पुरालेखित. अभिगमन तिथि 2012-07-03.
  3. "California ARB". मूल से 24 सितंबर 2015 को पुरालेखित. अभिगमन तिथि 11 सितंबर 2015.
  4. Health Canada Archived 2009-02-07 at the वेबैक मशीन
  5. Directive 2004/42/CE of the European Parliament and of the Council of 21 April 2004 on the limitation of emissions of volatile organic compounds due to the use of organic solvents in certain paints and varnishes and vehicle refinishing products Archived 2013-11-21 at the वेबैक मशीन EUR-Lex, European Union Publications Office. Retrieved on 2010-09-28.
  6. "USGS definition". मूल से 5 सितंबर 2015 को पुरालेखित. अभिगमन तिथि 11 सितंबर 2015.
  7. 40CFR141
  8. "Clean Water Act Analytical Methods | CWA Methods | US EPA" (PDF). Epa.gov. मूल से 24 दिसंबर 2010 को पुरालेखित (PDF). अभिगमन तिथि 2012-07-03.
  9. CERCLA and RCRA
  10. "Volatile Organic Compounds | Indoor Air | US Environmental Protection Agency". Epa.gov. 2010-11-17. मूल से 9 सितंबर 2015 को पुरालेखित. अभिगमन तिथि 2012-07-03.
  11. Goldstein, Allen H.; Galbally, Ian E. (2007). "Known and Unexplored Organic Constituents in the Earth's Atmosphere". Environmental Science & Technology. 41 (5): 1514–21. PMID 17396635. डीओआइ:10.1021/es072476p.
  12. Niinemets, Ülo; Loreto, Francesco; Reichstein, Markus (2004). "Physiological and physicochemical controls on foliar volatile organic compound emissions". Trends in Plant Science. 9 (4): 180–6. PMID 15063868. डीओआइ:10.1016/j.tplants.2004.02.006.
  13. Behr, Arno; Johnen, Leif (2009). "Myrcene as a Natural Base Chemical in Sustainable Chemistry: A Critical Review". ChemSusChem. 2 (12): 1072–95. PMID 20013989. डीओआइ:10.1002/cssc.200900186.
  14. Xie, Jenny. "Not All Tree Planting Programs Are Great for the Environment". City Lab. Atlantic Media. मूल से 20 जून 2014 को पुरालेखित. अभिगमन तिथि 20 June 2014.
  15. Farag, Mohamed A.; Fokar, Mohamed; Abd, Haggag; Zhang, Huiming; Allen, Randy D.; Paré, Paul W. (2004). "(Z)-3-Hexenol induces defense genes and downstream metabolites in maize". Planta. 220 (6): 900–9. PMID 15599762. डीओआइ:10.1007/s00425-004-1404-5.
  16. Stoye, D.; Funke, W.; Hoppe, L.; एवं अन्य (2006), "Paints and Coatings", Ullmann's Encyclopedia of Industrial Chemistry, आई॰ऍस॰बी॰ऍन॰ 3527306730, डीओआइ:10.1002/14356007.a18_359.pub2
  17. Wang, Shaobin; Ang, H.M.; Tade, Moses O. (2007). "Volatile organic compounds in indoor environment and photocatalytic oxidation: State of the art". Environment International. 33 (5): 694–705. PMID 17376530. डीओआइ:10.1016/j.envint.2007.02.011.
  18. Dales, R.; Liu, L.; Wheeler, A. J.; Gilbert, N. L. (2008). "Quality of indoor residential air and health". Canadian Medical Association Journal. 179 (2): 147–52. PMID 18625986. डीओआइ:10.1503/cmaj.070359. पी॰एम॰सी॰ 2443227. सन्दर्भ त्रुटि: <ref> अमान्य टैग है; "test" नाम कई बार विभिन्न सामग्रियों में परिभाषित हो चुका है
  19. Yu, Chuck; Crump, Derrick (1998). "A review of the emission of VOCs from polymeric materials used in buildings". Building and Environment. 33 (6): 357–74. डीओआइ:10.1016/S0360-1323(97)00055-3.
  20. Irigaray, P.; Newby, J.A.; Clapp, R.; Hardell, L.; Howard, V.; Montagnier, L.; Epstein, S.; Belpomme, D. (2007). "Lifestyle-related factors and environmental agents causing cancer: An overview". Biomedicine & Pharmacotherapy. 61 (10): 640–58. PMID 18055160. डीओआइ:10.1016/j.biopha.2007.10.006.
  21. "Who Says Alcohol and Benzene Don't Mix?". मूल से 15 अप्रैल 2008 को पुरालेखित. अभिगमन तिथि 11 सितंबर 2015.
  22. "An Introduction to Indoor Air Quality". मूल से 9 सितंबर 2015 को पुरालेखित. अभिगमन तिथि 11 सितंबर 2015.
  23. Jones, A.P. (1999). "Indoor air quality and health". Atmospheric Environment. 33 (28): 4535–64. डीओआइ:10.1016/S1352-2310(99)00272-1.
  24. Barro, R.; एवं अन्य (2009). "Analysis of industrial contaminants in indoor air: Part 1. Volatile organic compounds, carbonyl compounds, polycyclic aromatic hydrocarbons and polychlorinated biphenyls". Journal of Chromatography A. 1216 (3): 540–566. PMID 19019381. डीओआइ:10.1016/j.chroma.2008.10.117.
  25. Schlink, U; Rehwagen, M; Damm, M; Richter, M; Borte, M; Herbarth, O (2004). "Seasonal cycle of indoor-VOCs: Comparison of apartments and cities". Atmospheric Environment. 38 (8): 1181–90. डीओआइ:10.1016/j.atmosenv.2003.11.003.
  26. "Ecolabels, Quality Labels, and VOC emissions". Eurofins.com. मूल से 24 सितंबर 2015 को पुरालेखित. अभिगमन तिथि 2012-07-03.
  27. "EMICODE". मूल से 24 सितंबर 2015 को पुरालेखित. अभिगमन तिथि 11 सितंबर 2015.
  28. "M1 Finnish label". मूल से 24 सितंबर 2015 को पुरालेखित. अभिगमन तिथि 11 सितंबर 2015.
  29. "Blue Angel German ecolabel". मूल से 24 सितंबर 2015 को पुरालेखित. अभिगमन तिथि 11 सितंबर 2015.
  30. "Indoor Air Comfort". मूल से 8 सितंबर 2012 को पुरालेखित. अभिगमन तिथि 15 जून 2020.
  31. "CDPH Section 01350". मूल से 24 सितंबर 2015 को पुरालेखित. अभिगमन तिथि 11 सितंबर 2015.
  32. "IAQ Certified Products". मूल से 20 दिसंबर 2015 को पुरालेखित. अभिगमन तिथि 11 सितंबर 2015.
  33. Wolkoff, Peder; Kjaergaard, Søren K. (2007). "The dichotomy of relative humidity on indoor air quality". Environment International. 33 (6): 850–7. PMID 17499853. डीओआइ:10.1016/j.envint.2007.04.004.
  34. Mendell, M. J. (2007). "Indoor residential chemical emissions as risk factors for respiratory and allergic effects in children: A review". Indoor Air. 17 (4): 259–77. PMID 17661923. डीओआइ:10.1111/j.1600-0668.2007.00478.x.
  35. Wolkoff, P.; Wilkins, C. K.; Clausen, P. A.; Nielsen, G. D. (2006). "Organic compounds in office environments - sensory irritation, odor, measurements and the role of reactive chemistry". Indoor Air. 16 (1): 7–19. PMID 16420493. डीओआइ:10.1111/j.1600-0668.2005.00393.x.
  36. "What is Smog?", Canadian Council of Ministers of the Environment, CCME.ca Archived 2011-09-28 at the वेबैक मशीन
  37. "EPA -- An Introduction to Indoor Air Quality Pollutants and Sources of Indoor Air Pollution Volatile Organic Compounds (VOCs)". मूल से 9 सितंबर 2015 को पुरालेखित. अभिगमन तिथि 11 सितंबर 2015.
  38. Buszewski, B. A.; एवं अन्य (2007). "Human exhaled air analytics: Biomarkers of diseases". Biomedical Chromatography. 21 (6): 553–566. PMID 17431933. डीओआइ:10.1002/bmc.835.
  39. Miekisch, W.; Schubert, J. K.; Noeldge-Schomburg, G. F. E. (2004). "Diagnostic potential of breath analysis—focus on volatile organic compounds". Clinica Chimica Acta. 347: 25. डीओआइ:10.1016/j.cccn.2004.04.023.
  40. Mazzone, P. J. (2008). "Analysis of Volatile Organic Compounds in the Exhaled Breath for the Diagnosis of Lung Cancer". Journal of Thoracic Oncology. 3 (7): 774–780. PMID 18594325. डीओआइ:10.1097/JTO.0b013e31817c7439.
  41. MartíNez-Hurtado, J. L.; Davidson, C. A. B.; Blyth, J.; Lowe, C. R. (2010). "Holographic Detection of Hydrocarbon Gases and Other Volatile Organic Compounds". Langmuir. 26 (19): 15694–9. PMID 20836549. डीओआइ:10.1021/la102693m.
  42. Lattuati-Derieux, Agnès; Bonnassies-Termes, Sylvette; Lavédrine, Bertrand (2004). "Identification of volatile organic compounds emitted by a naturally aged book using solid-phase microextraction/gas chromatography/mass spectrometry". Journal of Chromatography A. 1026 (1–2): 9–18. PMID 14870711. डीओआइ:10.1016/j.chroma.2003.11.069.
  43. Biasioli, Franco; Yeretzian, Chahan; Märk, Tilmann D.; Dewulf, Jeroen; Van Langenhove, Herman (2011). "Direct-injection mass spectrometry adds the time dimension to (B)VOC analysis". Trends in Analytical Chemistry. 30 (7): 1003–1017. डीओआइ:10.1016/j.trac.2011.04.005.
  44. Ellis, Andrew M.; Mayhew, Christopher A. (2014). Proton Transfer Reaction Mass Spectrometry - Principles and Applications. Chichester, West Sussex, UK: John Wiley & Sons Ltd. आई॰ऍस॰बी॰ऍन॰ 978-1-405-17668-2.
  45. Sulzer, Philipp; Hartungen, Eugen; Hanel, Gernot; Feil, Stefan; Winkler, Klaus; Mutschlechner, Paul; Haidacher, Stefan; Schottkowsky, Ralf; Gunsch, Daniel; Seehauser, Hans; Striednig, Marcus; Jürschik, Simone; Breiev, Kostiantyn; Lanza, Matteo; Herbig, Jens; Märk, Lukas; Märk, Tilmann D.; Jordan, Alfons (2014). "A Proton Transfer Reaction-Quadrupole inferface Time-Of-Flight Mass Spectrometer (PTR-QiTOF): High speed due to extreme sensitivity". International Journal of Mass Spectrometry. 368: 1–5. डीओआइ:10.1016/j.ijms.2014.05.004.

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