2-Butanone methyl ethyl

Acetone and toluene were detected in the offgases at levels comparable to those in the Ml propellant offgas. No diethyl ether was reported for M28 propellant. A few ppm of 2-butanone (methyl ethyl ketone), another common solvent, were detected. 

Additional aldehydes and ketones were also included in the U.S. Nationwide Occurrence Study dimethylglyoxal (2,3-butanedione), cyanoformaldehyde, 2-butanone (methyl ethyl ketone), trans-2-hexanal, 5-keto-l-hexanal, and 6-hydroxy-2-hexanone [11, 13]. Dimethylglyoxal was the most consistently detected of these carbonyl compounds (up to 3.5 pg/L) and was found at higher levels in plants using ozone. Maximum levels of 0.3, 5.0, and 0.7 pg/L were observed for cyanoformaldehyde, 2-butanone, and trans-2-hexenal, respectively 6-hydroxy-2-hexanone and 5-keto-1 -hexanal were only detected in early stages of treatment, and not in finished waters. 

A 125 ml flask fitted with a magnetic stirring bar, a reflux condenser, a thermometer and a separatory funnel is charged with 7.2 g (9 ml, 0.1 mol) of 2-butanone (methyl ethyl ketone). From the separatory funnel a solution of 1.5 g (0.04 mol, 60% excess) of sodium borohydride in 15 ml of water is added dropwise with stirring at such a rate as to raise the temperature of the readion mixture to 40° and maintain it at 40-50°. Cooling with a water bath may be applied if the temperature rises above 50°. After the addition has been completed (approximately 30 minutes) the mixture is stirred until the temperature drops to 30°. It is then transferred to a separatory funnel and saturated with sodium chloride. The aqueous layer is drained and the organic layer is dried with anhydrous potassium carbonate. Distillation affords 5.5-6.0g (73-81%) of 2-butanol, b.p. 90-95°. 

Chromosomal aberrations in peripheral lymphocytes were also reported in a study of about 40 workers who had been occupationally exposed to trace quantities of 2-butanone (methyl ethyl ketone), butyl acetate, toluene, cyclohexanone and xylene in addition to dimethylfonnamide. Blood samples were taken at two Ibur-nionth intervals, when exposure was to an average of 180 and 150 mg/nr dimethylformamide, respectively. The frequencies of chromosomal aberrations were 3.82% and 2.74% at these two sampling times. Subsequent sampling at tliree six-month intervals, when average dimethylformamide exposures were to 50, 40 and 35 mg/m- , gave lower aberration frequencies of 1.59%, 1.58% and 1.49%. Aberration frequencies in two control groups were 1.61% and 1.10% (Koudela Spazier, 1981). 

Carpenter et al. (1988) carried out a nested case-control study of cancer of the central nervous system among workers at two nuclear facilities located in Tennessee (United States). They identified 89 cases (72 males and 17 females) who had died between 1943 and 1979. Four controls, living at the time the case was diagnosed, were matched to each case. Job history records were scrutinized by an industrial hygienist to assess potential exposure to each of 26 chemicals or chemical groups. Toluene, xylene (see this volume) and 2-butanone (methyl ethyl ketone) were evaluated as one chemical group the matched relative risk was 2.0 (95% confidence interval (Cl), 0.7-5.5 n = 28) in comparison with unexposed workers. Almost all cases had had low exposure, according to the classification used and there was no dose-response trend. The authors stated that the relative risks w ere adjusted for internal and external exposure to radiation. 

Walker et al. (1993) conducted a cohort mortality study among 7814 shoe-manufacturing workers (2529 males and 5285 females) from two plants in Ohio (United States) that have been in operation since the 1930s. The workers, men and women, were potentially exposed to solvents and solvent-based adhesives. It was thought that toluene may have been a predominant exposure, but a hygiene survey in 1977-79 showed that, in addition to toluene (10 measurements ranged from 10 ppm to 72 ppm [38-270 mg/m3]), there were also 2-butanone (methyl ethyl ketone), acetone, hexane and... 

BUTANONE (METHYL ETHYL KETONE) (Tables III, VI, and VII) n-Octane n-Dodecane... 

Butanone (Methyl ethyl ketone) 96 Carbon tetrachloride... 

Homologous Polymers. As the size of a molecule increases, it is expected that its diffusion coefficient will decrease. Figure 5 shows a plot of D° vs. M for solutions of polystyrene in 2-butanone (methyl ethyl ketone) where the relationship between D° and M may be expressed by the semiempirical formula... 

Typical infrared spectra are shown in Figure 9-9 for 2-propanone (acetone), CH3—CO—CH3, and 2-butanone (methyl ethyl ketone), CH3— CO—CH2—CH3. In accord with current practice, the position of absorption... 

Common Name Methyl ethyl ketone Synonym 2-butanone, butan-2-one, MEK Chemical Name 2-butanone, methyl ethyl ketone CAS Registry No 78-93-3 Molecular Formula C4H8O, CH3CH2COCH3 Molecular Weight 72.106 Melting Point (°C) ... 

Reported vapor pressures of 2-butanone (methyl ethyl ketone) at various temperatures and the coefficients for the vapor pressure equations... 

Butanone (methyl ethyl ketone) vapor pressure vs. 1/T... 

R 1 R—C=0 Ketone CH3 1 CH,CH2C=0 2-Butanone Methyl ethyl ketone... 

Butanone, Methyl ethyl ketone, MEK (CH3COCH2CH3) 80 An excellent solvent with many of the most desirable properties of a good crystallization solvent. 

MEK, 2-butanone, methyl ethyl ketone MEMO, 2-methoxyethoxymethylchloride Mercurochrome, mercury dibromofluorescein MES, 2-(7V-morpholino)-ethanesulfonic acid MESNA, Na 2-mercaptoethanesulfonate Metal impurities, by complexation by ion exchange resins by precipitation removal by extraction removal from reagents removal of lead removal of iron Methylarenes... 

The hydrocarbon groups represented by Rand R can be identical or different. The most common ketones are 2-propanone (acetone), CFf3COCFf3, and 2-butanone (methyl ethyl ketone or MEK), CFf3COCFf2CFf3. Both compounds are solvents frequently used in nail polish removers (Figure 17.12). 

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