A single fluorinated urinary metabolite, identified as 2,2-dichloro-2-fluoro-ethyl glucuronide, was found in rats exposed to HCFC 141b (56 g/cu m) in air for 2 hr. The metabolism was reported to be similar to that of its chlorinated analogue 1,1,1-trichloroethane, which is metabolized to 2,2,2-trichloroethanol and excreted as it glucuronate conjugate and as trichloroacetic acid.
In a pilot study for absorption and metabolism of HCFC 141b, seven groups of five male rats were exposed to the vapor by inhalation in a closed loop exposure system (concentrations ranging from 0.4 to 12 g/cu m). No metabolism was detected but the sensitivity of the method is such that it will not detect metabolism below 0.15%.
Human subjects were exposed by inhalation to 250, 500, and 1000 ppm 1,1-dichloro-1-fluoroethane (HCFC-141b) for 4 hr, and urine samples were collected from 0-4, 4-12, and 12-24 hr for metabolite analysis. 'OF nuclear magnetic resonance spectroscopic analysis of urine samples from exposed subjects showed that 2,2-dichloro-2-fluoroethyl glucuronide and dichlorofluoroacetic acid were the major and minor metabolites, respectively, of 1,1-dichloro-1-fluoroethane. Urinary 2,2-dichloro-2-fluoroethyl glucuronide was hydrolyzed to 2,2-dichloro-2-fluoroethanol by incubation with beta-glucuronidase, and the released 2,2-dichloro-2-fluoroethanol was quantified by gas chromatography/mass spectrometry. Concentrations of 2,2-dichloro-2-fluoroethanol were highest in the urine samples collected 4-12 hr after exposure, but 2,2-dichloro-2-fluoroethanol was also detected in the samples collected 0-4 and 12-24 hr after exposure. Exposure concentration-dependent excretion of 2,2-dichloro-2-fluoroethanol, obtained by hydrolysis of 2,2-dichloro-2-fluoroethyl glucuronide, was observed in seven of the eight subjects studied. In conclusion, 1,1-dichloro-1-fluoroethane is metabolized in human subjects to 2,2-dichloro-2-fluoroethanol, which is conjugated with glucuronic acid and excreted as its glucuronide in urine in a time- and exposure concentration-dependent manner.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
暴露途径
这种物质可以通过吸入被身体吸收。
The substance can be absorbed into the body by inhalation.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
毒理性
吸入症状
昏昏欲睡。困惑。无意识。
Drowsiness. Confusion. Unconsciousness.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
毒理性
皮肤症状
红肿。疼痛。
Redness. Pain.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
毒理性
眼睛症状
红肿。疼痛。
Redness. Pain.
来源:ILO-WHO International Chemical Safety Cards (ICSCs)
毒理性
副作用
神经毒素 - 急性溶剂综合症
Neurotoxin - Acute solvent syndrome
来源:Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
... MAIN FACTOR AFFECTING FATE OF FLUOROCARBONS IS BODY FAT, WHERE THEY ARE CONCENTRATED & SLOWLY RELEASED INTO BLOOD @ CONCN THAT SHOULD NOT CAUSE ANY RISK OF CARDIAC SENSITIZATION. /FLUOROCARBONS/
THERE IS A SIGNIFICANT ACCUMULATION OF FLUOROCARBONS IN BRAIN, LIVER & LUNG COMPARED TO BLOOD LEVELS, SIGNIFYING A TISSUE DISTRIBUTION OF FLUOROCARBONS SIMILAR TO THAT OF CHLOROFORM. /FLUOROCARBONS/
Absorption of fluorocarbons is much lower after oral ingestion (35-48 times) than after inhalation. ... The lung generally has the highest fluorocarbon concentrations on autopsy. /Fluorocarbons/
Although fluorocarbons cause cardiac sensitization in certain animal species, rapid elimination prevents the development of cardiotoxic concentrations from aerosol bronchodilator use except at exceedingly high doses (12 to 24 doses in 2 minutes). /Fluorocarbons/
FLUOROCARBON COMPOUNDS ARE LIPID-SOLUBLE AND THUS ARE GENERALLY WELL ABSORBED THROUGH LUNG. ABSORPTION AFTER INGESTION IS 35 TO 48 TIMES LOWER THAN AFTER INHALATION. ... FLUOROCARBONS ARE ELIMINATED BY WAY OF LUNG. /FLUOROCARBON COMPOUNDS/
in vivo Cell Lineage Analysis During Chemical Hepatocarcinogenesis in Rats Using Retroviral-Mediated Gene Transfer: Evidence for Dedifferentiation of Mature Hepatocytes
摘要：
Feeding adult rats with a diet containing 2-acetylaminofluorene (2-AAF) results in suppression of hepatocyte proliferation and stimulation of oval cell proliferation. Although oval cells may be facultative liver stem cells, the actual relationship between oval cells and liver cancer has not been clearly established in vivo. Our goal was to label hepatic cells in vivo using retroviral vectors and follow their fate during the early steps of chemically induced hepatocarcinogenesis. Oval cell proliferation was induced by continuous feeding with a carcinogenic diet containing 2-AAF. We used two different strategies to genetically label hepatic cells: (a) labeling of proliferating cells in rats fed 2-AAF by injecting recombinant retroviral vectors containing the beta-galactosidase gene either in a peripheral vein or in the common bile duct at the peak of oval cell proliferation and (b) prelabeling of hepatocytes by intravenously injecting recombinant vectors 1 day after partial hepatectomy and 1 week before subsequent administration of 2-AAF. Using the first strategy, transgene expression occurred in both oval cells and hepatocytes. Using the second strategy, we could selectively label, and hence study the fate of, differentiated hepatocytes. In the latter case, we observed clusters of beta-galactosidase-positive hepatocytes, some of them also expressing preneoplastic markers such as gamma-glutamyl transpeptidase as well as the placental form of glutathione-S-transferase. These results demonstrate that preneoplastic foci can originate from mature hepatocytes and are consistent with the hypothesis that dedifferentiation of mature hepatocytes may occur during the course of carcinogenic regimen.
1,1,1,3,3,-pentafluorobutane (HFC-365mfc): atmospheric degradation and contribution to radiative forcing
摘要：
The rate constant for the reaction of the hydroxyl radical with 1,1,1,7,7-pentafluorobutane (HFC-365mfc) has been determined over the temperature range 278-323 K using a relative rate technique. The results provide a value of k(OH + CF3CH2CF2CH3) = 2.0 X 10(-12) exp(- 1750 +/- 400/T) cm(3) molecule(-1) s(-1) based on k(OH + CH3CCl3) = 1.8 X 10(-12) exp (- 1550 +/- 150/T) cm(3) molecule(-1) s(-1) for the rate constant of the reference reaction. Assuming the major atmospheric removal process is via reaction with OH in the troposphere, the rate constant data from this work gives an estimate of 10.8 years for the tropospheric lifetime of HFC-365mfc. The overall atmospheric lifetime obtained by taking into account a minor contribution from degradation in the stratosphere, is estimated to be 10.2 years. The rate constant for the reaction of Cl atoms with 1,1,1,3,3-pentafluorobutane was also determined at 298 +/- 2 K using the relative rate method, k(Cl + CF3CH2CF2CH3) = (1.1 +/- 0.3) x 10(-15) cm(3) molecule(-1) s(-1). The chlorine initiated photooxidation of CF3CH2CF2CH3 was investigated from 273-330 K and as a function of O-2 pressure at 1 atmosphere total pressure using Fourier transform infrared spectroscopy Under all conditions the major carbon-containing products were CF2O and CO2, with smaller amounts of CF3O3CF3. In order to ascertain the relative importance of hydrogen abstraction from the -CH2- and -CH3 groups in CF3CH2CF2CH3, rate constants for the reaction of OH radicals and CI atoms with the structurally similar compounds CF3CH2CCl2F and CF3CH2CF3 were also determined at 298 K k(OH + CF3CH2CCl2F) = (8 +/- 3) X 10(-16) cm(3) molecule(-1) s(-1); k(OH + CF3CH2CF3) = (3.5 +/- 1.5) X 10(-16) cm(3) molecule(-1) s(-1); k(Cl + CF3CH2CCl2F) = (3.5 +/- 1.5) X 10(-17) cm(3) molecule(-1) s(-1)]; k(Cl + CF3CH2CF3) < 1 X 10(-17) cm(3) molecule(-1) s(-1). The results indicate that the most probable site for H-atom abstraction from CF3CH2CF2CH3 is the methyl group and that the formation of carbonyl compounds containing more than a single carbon atom will be negligible under atmospheric conditions, carbonyl difluoride and carbon dioxide being the main degradation products. Finally, accurate infrared absorption cross-sections have been measured for CF3CH2CF2CH3, and jointly used with the calculated overall atmospheric lifetime of 10.2 years, in the NCAR chemical-radiative model, to determine the radiative forcing of climate by this CFC alternative. The steady-state Halocarbon Global Warming Potential, relative to CFC-11, is 0.17. The Global Warming Potentials relative to CO2 are found to be 2210, 790, and 250, for integration time-horizons of 20, 100, and 500 years, respectively. (C) 1997 John Wiley & Sons, Inc.
Method of making difluoromethane, 1,1,1-trifluoroethane and 1,1-difluoroethane
申请人：Merkel C. Daniel
公开号：US20050222472A1
公开（公告）日：2005-10-06
A process for the production of difluoromethane (HFC-32), 1,1,1-trifluoroethane (HFC-143a) and 1,1-difluoroethane (HFC-152a). In the process the following steps are employed: (a) providing a reaction vessel, (b) providing in the reaction vessel activated carbon impregnated with a strong Lewis acid fluorination catalys selected from halides of As, Sb, Al, TI, In, V, Nb, Ta, Ti, Zr and Hf, (c) activating the catalyst by passing through the activated carbon impregnated with a strong Lewis acid fluorination catalyst anhydrous hydrogen fluoride gas and chlorine gas, (d) contacting, in a vapor state in the reaction vessel containing the activated catalyst, hydrogen fluoride and one or more halogenated hydrocarbons selected from chlorofluoromethane, dichloromethane, 1,1,1-trichloroethane, vinyl chloride, 1,1-dichloroethylene, 1.2-dichloroethylene, 1,2-dichloroethane, and 1,1-dichloroethane for a time and at a temperature to produce a product stream comprising hydrofluorocarbon product(s) corresponding to the chlorinated hydrocarbon reactant(s), and one or more of hydrogen chloride, unreactacted chlorinated hydrocarbon reactant(s), under-fluorinated intermediates, and unreacted hydrogen fluoride, and (e) separating the hydrofluorocarbon product(s) from the product stream.
A porous aluminum fluoride on which SbCl
x
F
5-x
(wherein x represents a numeral of 0 to 5) is supported, SbCl
x
F
5-x
being obtainable by supporting SbCl, or the like on a porous aluminum fluoride and treating it with hydrogen fluoride. The resulting porous aluminum fluoride has a high activity as a fluorinating agent, a fluorination catalyst, or the like, is easy to handle, can be used for a flow-type reaction, and also can be used even at a high temperature.
在多孔氟化铝上支持SbCl
x
F
5-x
（其中x表示0到5的数字），可以得到SbCl
x
F
5-x
，通过在多孔氟化铝上支持SbCl或类似物质，并用氢氟酸处理。所得的多孔氟化铝具有高活性作为氟化剂、氟化催化剂等，易于处理，可用于流动式反应，甚至可在高温下使用。
Experimental Studies of Ozone Depletion by Chlorofluorocarbons (CFC’s), Bromofluorocarbons (BFC’s), Hydrochlorofluorocarbons (HCFC’s), and CH<sub>3</sub>Br Using a 6-m<sup>3</sup>Photochemical Chamber
作者：Nobuaki Washida、Takashi Imamura、Hiroshi Bandow
DOI：10.1246/bcsj.69.535
日期：1996.3
BFC’s than in the CFC’s. According to a box-model simulation, in the CFCl3 system 90% of the catalytic cycle proceeds from reactions of Cl + O3 → ClO + O2 and ClO + O → Cl + O2. On the other hand, in the CF3Br system 90% of the catalytic cycle is governed by the following reactions: Br + O3 → BrO + O2 and BrO + BrO → 2Br + O2. The HCFC’s and CH3Br can destroy the ozone with sufficient potential as CFC’s
A halogenated alkene is reacted with HF in the presence of TaF.sub.5 or NbF.sub.5 to produce a fluorinated alkane. Exemplary is the reaction of tetrachloroethene with HF in the presence of TaF.sub.5 to produce 1,2,2-trichloro-1,1-difluoroethane and 1,1,2,2-tetrachloro-1-fluoroethane.
Room-temperature catalytic fluorination of C1 and C2 chlorocarbons and chlorohydrocarbons on fluorinated Fe3O4 and Co3O4
作者：James Thomson
DOI：10.1039/ft9949003585
日期：——
A study of the room-temperature reactions of a series of C1 and C2 chlorohydrocarbon and chlorocarbon substrate molecules with fluorinated iron (II, III) oxide and cobalt (II, III) oxide has been conducted. The results show that fluorinated iron(II, III) oxide exhibits an ability to incorporate fluorine into the following substrates in the order: Cl2CCCl2 > H2CCCl2 > CH3CCl3 > CHCl3 > CH2Cl2 > CH2ClCCl3 > CCI4 > CHCl2CHCl2. The fluorinated cobalt(II,III) oxide gave the reactivity series CHCl3 > CCl4 > H2CCCl2 > CHCl2CHCl2 > CH2CI2 > CH3CCl3 > CCl2CCl2 > CH2ClCl3. Reactions of C1 chlorohydrocarbon or chlorocarbon probe molecules with fluorinated Fe3O4 gave predominately C1 chlorofluorohydrocarbon and chlorofluorocarbon products, respectively, whereas fluorinated cobalt(II, III) oxide produced predominately C2 chlorofluorohydrocarbon and chlorofluorocarbons. For fluorinated Co3O4 the distribution of C2 products obtained from C1 chlorohydrocarbon precursor molecules is consistent with the formation of radical intermediates at strong Lewis acid surfaces. C2 chlorohydrocarbons exhibit a fluorine for chlorine (F-for-Cl) exchange reaction through the catalytic dehydrochlorination of the substrate to the alkenic intermediate. The F-for-Cl exchange process was dependent upon the ability of the substrate material to undergo dehydrochlorination; the inability of a substrate to undergo dehydrochlorination results in the fluorination process proceeding through the formation of chlorocarbon or chlorohydrocarbon radical intermediates.
