Toluene testing

Of a series of fluorinated benzenes and fluorinated toluenes tested with and without... 

Colloid characterization is not the classical application of Th-FFF. Nevertheless, Th-FFF was first applied to silica particles suspended in toluene testing a correlation between thermal diffusion and thermal conductivity [397]. Although a weak retention was achieved, no further studies were carried out until the work of Liu and Giddings [398] who fractionated polystyrene latex beads ranging from 90 to 430 nm in acetonitrile applying a low AT of only 17 K. More recently, polystyrene and polybutadiene latexes with particle sizes between 50 pm and 10 pm were also fractionated in aqueous suspensions despite the weak thermal diffusion [215] (see Fig. 30). Th-FFF is also sensitive to the surface composition of colloids (see the work on block copolymer micelles), recent effort in this area has been devoted to analyzing surfaces of colloidal particles [399,400]. 

Reaction Sequence A 100 mL of a 1C % aqueous solution of KI are placed in each Erlenmeyer flask. 100 ml, of chlorine water are added to one flask, 100 mL of bromine water to the other in both cases the solution immediately turns brown. The contents of the two flasks are now transferred to the five large test tubes, to which the following substances are added test tube 1, freshly pre pared starch solution test tube 2, a few grams of solid KI test tube 3, diethyl ether test tube 4, toluene test tube 5, -hcxanc (or -hcptanc). The contents of the first test tube turn to a deep blue-black, while the brown color in the second becomes much deeper. In the other test tubes two layers are formed in each case the lower aqueous layer is much lighter in color, while the upper organic layer.s arc colored yellow(test tube 3), wine-red (test tube 4) and violet (test tube 5) respectively. 

Figure 3 Catalytic oxidation of toluene, testing conditions 0.5g immobilised fluorous cobalt (powder C), 0.2 mmol NaBr, 14.1 mmol toluene, 500 pi H2O, trace methane as internal standard, 10 bar O2 and 150 bar CO2 were blended at 120°C performance of the fresh catalyst (a) a repeated test of recovered catalysts (b) performance of a recovered catalyst from b with addition of O.lmmol cobalt acetate (c).

Of the C-2-substituted toluenes tested, p-xylene and 2-chlorotoluene, only o-xylene was found to undergo bioconversion, giving 4-hydroxy-2-methylbenzoate as a major product. Less than 1% of the initial 100 ppm o-xylene was found to undergo bioconversion, whereas 6% conversion of toluene, and 86% conversion of 3,4-dimethylphenol, the predicted product of o-xylene conversion by T4MO, were... 

W2(g) = weight of toluene required to make the volume of polyol/toluene test solution up to 400 cm at 25 1 °C... 

Physical Properties. Benzene, C H, toluene, C Hj-CH, and petrol (a mixture of aliphatic hydrocarbons, e.g., pentane, hexane, etc.) are colourless liquids, insoluble in and lighter than water. Benzene and toluene, which have similar odours, are not readily distinguishable chemically, and their physical constants should therefore be carefully noted benzene, m.p. 5 (solidifies when a few ml. in a dry test-tube are chilled in ice-water), b.p. 8i toluene, m.p. —93°, b.p. 110°. Petroleum has a characteristic odour. 

For alcohols of b.p. below 150°, mix 0- 5 g. of 3-nitrophthalic anhydride (Section VII,19) and 0-5 ml. (0-4 g.) of the dry alcohol in a test-tube fitted with a short condenser, and heat under reflux for 10 minutes after the mixture liquefies. For alcohols boiling above 150°, use the same quantities of reactants, add 5 ml. of dry toluene, heat under reflux until all the anhydride has dissolved and then for 20 minutes more remove the toluene under reduced pressure (suction with water pump). The reaction product usually solidifies upon cooling, particularly upon rubbing with a glass rod and standing. If it does not crystallise, extract it with dilute sodium bicarbonate solution, wash the extract with ether, and acidify. Recrystallise from hot water, or from 30 to 40 per cent, ethanol or from toluene. It may be noted that the m.p. of 3-nitrophthalic acid is 218°. 

An additional useful test is to distil the acid or its sodium salt with soda lime. Heat 0.5 g. of the acid or its sodium salt with 0 2 g. of soda lime in an ignition tube to make certain that there is no explosion. Then grind together 0-5 g. of the acid with 3 g. of soda hme, place the mixture in a Pyrex test-tube and cover it with an equal bulk of soda hme. Fit a wide dehvery tube dipping into an empty test-tube. Clamp the tube near the mouth. Heat the soda lime first and then the mixture gradually to a dull-red heat. Examine the product this may consist of aromatic hydrocarbons or derivatives, e.g., phenol from sahcyUc acid, anisole from anisic acid, toluene from toluic acid, etc. 

Methyl p-toluenesulphonate. This, and other alkyl esters, may be prepared in a somewhat similar manner to the n-butyl ester with good results. Use 500 g. (632 ml.) of methyl alcohol contained in a 1 litre three-necked or bolt-head flask. Add 500 g. of powdered pure p-toluene-sulphonyl chloride with mechanical stirring. Add from a separatory funnel 420 g. of 25 per cent, sodium hydroxide solution drop by drop maintain the temperature of the mixture at 23-27°. When all the alkali has been introduced, test the mixture with litmus if it is not alkaline, add more alkali until the mixture is neutral. Allow to stand for several hours the lower layer is the eater and the upper one consists of alcohol. Separate the ester, wash it with water, then with 4 per cent, sodium carbonate solution and finally with water. Dry over a little anhydrous magnesium sulphate, and distil under reduced pressure. Collect the methyl p-toluenesulphonate at 161°/10 mm. this solidifies on cooling and melts at 28°. The yield is 440 g. 

Specifications and Analytical Methods. Butanediol is specified as 99.5% minimum pure, determined by gas chromatography (gc), sohdifying at 19.6°C minimum. Moisture is 0.04% maximum, determined by Kad-Fischer analysis (dkecdy or of a toluene a2eotrope). The color is APHA 5 maximum, and the Hardy color (polyester test) is APHA 200 maximum. The carbonyl number is 0.5 mg KOH/g maximum the acetal content can also be measured dkecdy by gc. 

Membranes and Osmosis. Membranes based on PEI can be used for the dehydration of organic solvents such as 2-propanol, methyl ethyl ketone, and toluene (451), and for concentrating seawater (452—454). On exposure to ultrasound waves, aqueous PEI salt solutions and brominated poly(2,6-dimethylphenylene oxide) form stable emulsions from which it is possible to cast membranes in which submicrometer capsules of the salt solution ate embedded (455). The rate of release of the salt solution can be altered by surface—active substances. In membranes, PEI can act as a proton source in the generation of a photocurrent (456). The formation of a PEI coating on ion-exchange membranes modifies the transport properties and results in permanent selectivity of the membrane (457). The electrochemical testing of salts (458) is another possible appHcation of PEI. 

Analytical and Test Methods. o-Nitrotoluene can be analyzed for purity and isomer content by infrared spectroscopy with an accuracy of about 1%. -Nitrotoluene content can be estimated by the decomposition of the isomeric toluene diazonium chlorides because the ortho and meta isomers decompose more readily than the para isomer. A colorimetric method for determining the content of the various isomers is based on the color which forms when the mononitrotoluenes are dissolved in sulfuric acid (45). From the absorption of the sulfuric acid solution at 436 and 305 nm, the ortho and para isomer content can be deterrnined, and the meta isomer can be obtained by difference. However, this and other colorimetric methods are subject to possible interferences from other aromatic nitro compounds. A titrimetric method, based on the reduction of the nitro group with titanium(III) sulfate or chloride, can be used to determine mononitrotoluenes (32). Chromatographic methods, eg, gas chromatography or high pressure Hquid chromatography, are well suited for the deterrnination of mononitrotoluenes as well as its individual isomers. Freezing points are used commonly as indicators of purity of the various isomers. 

Health and Safety Factors. Animal-feeding studies of DMPPO itself have shown it to be nontoxic on ingestion. The solvents, catalyst, and monomers that are used to prepare the polymers, however, should be handled with caution. Eor example, for the preparation of DMPPO, the amines used as part of the catalyst are flammable toxic on ingestion, absorption, and inhalation and are also severe skin and respiratory irritants (see Amines). Toluene, a solvent for DMPPO, is not a highly toxic material in inhalation testing the TLV (71) is set at 375 mg/m, and the lowest toxic concentration is reported to be 100—200 ppm (72). Toxicity of 2,6-dimethylphenol is typical of alkylphenols (qv), eg, for mice, the acute dermal toxicity is LD q, 4000 mg/kg, whereas the acute oral toxicity is LD q, 980 mg/kg (73). The Noryl blends of DMPPO and polystyrene have PDA approval for reuse food apphcations. 

Tables 16 and 17 Hst tke analytical test methods for different properties of interest. The Manufacturing Chemists Association, Inc. (MCA) has pubUshed the Chemical Safety Data Sheet SD 63, which describes in detail procedures for safe handling of use of toluene (46). The Interstate Commerce Commission classifies toluene as a flammable Hquid. Accordingly, it must be packaged in authorized containers, and shipping must comply with ICC regulations. Properties related to safe handling are autoignition temperature, 536°C explosive limits, 1.27—7.0 vol % in air and flash point 4.4°C, closed cup.

Rapid, simple, quaUtative methods suitable for determining the presence of benzene in the workplace or surroundings have been utilized since the 1930s. Many early tests offered methods for detection of aromatics but were not specific for benzene. A straightforward test allowing selective detection of benzene involves nitration of a sample to y -dinitrobenzene and reaction of the resultant ether extract with an ethanoHc solution of sodium hydroxide and methyl ethyl ketone (2-butanone), followed by the addition of acetic acid to eliminate interferences from toluene and xylenes. Benzene imparts a persistent red color to the solution (87). The method is claimed to be sensitive to concentrations as low as 0.27 ppm benzene from 10 mL air samples. 

Solution Viscosity. Solution viscosity is determined in solvent blends of toluene, ethyl alcohol, and ethyl acetate. The solvent blend and concentration of CN varies according to the viscosity and nitrogen content of the CN being tested. Viscosities are measured at 25°C by the falling-hall method. The results are ordinarily expressed in terms of seconds required for a 2.4 mm diameter steel ball to fall a distance of 5.08 cm through the... 

A series of tests using Amberlite IR-12 (sulfonated polystyrene resin) to esterify diethylene glycol (DEG) using toluene as the entrainer for removal of water gave the results in Table 1 (53). 

An easy, rapid and environmentally friendly methodology was developed for the extraetion of pyrethroid inseetieide residues from semi permeable membrane deviees (SPMD), based in a mierowave-assisted extraetion, in front of a dialysis method nowadays widely employed. Several solvent sueh as hexane, toluene, aeetonitrile, eyelohexane and ethyl aeetate were tested as mierowave-assisted extraetion solvent. Mixtures of hexane and toluene with aeetone were also assayed and provide better results than single solvents. 

Katz et al. tested the theory further and measured the distribution coefficient of n-pentanol between mixtures of carbon tetrachloride and toluene and pure water and mixtures of n-heptane and n-chloroheptane and pure water. The results they obtained are shown in Figure 17. The linear relationship between the distribution coefficient and the volume fraction of the respective solvent was again confirmed. It is seen that the distribution coefficient of -pentanol between water and pure carbon tetrachloride is about 2.2 and that an equivalent value for the distribution coefficient of n-pentanol was obtained between water and a mixture containing 82%v/v chloroheptane and 18%v/v of n-heptane. The experiment with toluene was repeated using a mixture of 82 %v/v chloroheptane and 18% n-heptane mixture in place of carbon tetrachloride which was, in fact, a ternary mixture comprising of toluene, chloroheptane and n-heptane. The chloroheptane and n-heptane was always in the ratio of 82/18 by volume to simulate the interactive character of carbon tetrachloride. 

A man was asked to clean a 45-m tank that had contained toluene. It was 20 ft (6 m) tall and 10 ft (3 m) diameter. It had not been gas-freed, and the atmosphere had apparently not been tested. He entered the tank through the 16-in.-diameter top opening, using a rope for descent. Self-contained breathing apparatus was available on the job, but he did not wear it. He was overcome by tbe vapor and lack of air and collapsed on the floor of the tank. 

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