Acetone measurement

Figure 10.12 shows data for cellulose nitrate in acetone measured at Xo = 436 nm, and plotted in the manner suggested in Eq. (10.89). The following example completes the analysis of these data. 

Arnold, F., G. Knop, and H. Ziereis. 1986. Acetone measurements in the upper troposphere and lower stratosphere — implications for hydroxyl radical abundances. Nature 321 505-507. 

Figure 9.13 Influence of quench volumetric ratio (volume of water used as antisolvent/volume of quench water) on flnal nanospheres size. O, 0.125 O, 0.25 A, 0.5 , 1.0 non-quenched particles are shown for comparison ( ). PCL (M = 14,000) 6 mg/mL, in acetone, measured after synthesis (and quench) in CIJM-dl.

P Traub, K Stephan. High-pressure phase equilibria of the system C02-water-acetone measured with a new apparatus. Chem Eng Sci 45 751—758, 1990. 

Figure 5 Mass spectra can be considered as points or vectors in a multidimensional spectral space. For simplicity only two mass numbers (43, 58) have been selected in this example. A , abundance (peak height in %B) at mass m U, spectrum from unknown R1, reference spectrum of propanal R2, reference spectrum of acetone. Measures for spectral similarity are the Euclidean distance (d), the city block distance (A43 + Ajs) or the cosine of angle a (equivalent to S, in Eqn [2]).

Figure IX-D-6. Stern-Volmer plot of l/ I>co versus pressure of added nitrogen gas. Experiments were all performed using 248 lun excitation of acetone. Measurements of OchjCO reported by Rajakumar et al. (2008) were converted to CO data using the mass balance expression, co = 1 - cH3CO- The data for <1>ch3 determined by Khamaganov et al. (2007) were converted to equivalent values of co using the expression, 4>co =

When there is significant random error in all the variables, as in this example, the maximum-likelihood method can lead to better parameter estimates than those obtained by other methods. When Barker s method was used to estimate the van Laar parameters for the acetone-methanol system from these data, it was estimated that = 0.960 and A j = 0.633, compared with A 2 0.857 and A2- = 0.681 using the method of maximum likelihood. Barker s method uses only the P-T-x data and assumes that the T and x measurements are error free. 

Measured Variables and Estimates of Their True Values for Acetone(1)/Methanol(2) System (Othmer, 1928)... 

Hauck G and Arnold F 1984 Improved positive-ion composition measurements in the upper troposphere and lower stratosphere and the detection of acetone Nature 311 547-50... 

The following data were collected during a kinetic study of the iodination of acetone by measuring the concentration of unreacted I2 in solution. ... 

Bhatnagar and Biswast measured the turbidity at 436 nm of 2l single sample of poly(methyl methacrylate) in several solvents, including acetone and methyl ethyl ketone (MEK) ... 

The specifications set the maximum vol % of solvent that may be added to the cylinder shell (measured by its water capacity). The volume of solvent also varies with the capacity of the cylinder. Cylinders in the 90—92% porosity range with a capacity above 9.1 kg of water may contain a maximum acetone charge of 43.4%, whereas those with 9.1 kg or less water capacity may contain up to 41.8 vol %. The first category of cylinders are normally referred to as welding cylinders and the latter as small tanks (those with 0.28 and 1.12 m acetylene capacity). 

Health and Safety Factors. MEK is slightly more toxic than acetone, but is not considered highly toxic, and nor does it exhibit cumulative toxicological properties. The OSHA time weighted average iu air is 200 ppm other measured toxicity values are shown iu Table 3. Methyl ethyl ketone is highly flammable. 

Yields of excited states from 1,2-dioxetane decomposition have been determined by two methods. Using a photochemical method (17,18) excited acetone from TMD is trapped with /n j -l,2-dicyanoethylene (DCE). Triplet acetone gives i7j -l,2-dicyanoethylene with DCE, whereas singlet acetone gives 2,2-dimethyl-3,4-dicyanooxetane. By measuring the yields of these two products the yields of the two acetone excited states could be determined. The yields of triplet ketone (6) from dioxetanes are determined with a similar technique. 

Sorbic acid and its salts are highly refined to obtain the necessary purity for use in foods. The quaUty requirements are defined by the Food Chemicals Codex (Table 3). Codistillation or recrystaUization from water, alcohoHc solutions, or acetone is used to obtain sorbic acid and potassium sorbate of a purity that passes not only the Codex requirements but is sufficient for long-term storage. Measurement of the peroxide content and heat stabiUty can further determine the presence of low amounts of impurities. The presence of isomers, other than the trans,trans form, causes instabiUty and affects the melting point. 

Content of prime - tertiary peroxide groups was measured by the quantity of products of complete decay, which were measured by chromatography. It is known that the main contents in products of the complete decay of Oct-MA-TBPMM samples are acetone and 2,2-dimethylpropanol, which arise in reactions of chain fragmentation of tert-butylperoxy radical or in reaction of chain transfer of this radical. In this case the sum of acetone and 2,2-dimethylpropanol molecules is equal to the quantity of peroxide groups in polymer. As an internal standard we used chloroform. 

The proper volume of acetylene is measured with a water gasometer as described in Ovg. Synth., Colleat. Vol. 1 1941, 230, with two modifications (a) Two traps immersed in an acetone-dry ice bath at -65°C are placed between the acetylene tank and the gasometer in order to remove acetone. (b) The washing bottles between the gasometer and the reaction flask are replaced by a drying tube (2 x 30-cm column packed with anhydrous CaCl2). 

This successful commercial utilisation of poly(methyl methacrylate) is due in no small measure of the process of producing the monomer from acetone developed by Crawford of ICI which enabled the polymer to be produced at a competitive price. Some details of the process as operated by the Rohm and Hass Company of Philadelphia have been disclosed. ... 

The reactor in Fig. 5 operates as follows. A feed solution containing a given concentration of pollutant is pumped to the adsorbent module at a fixed volumetric flow rate. The module is kept isothermal by a temperature control unit, such as a surrounding water bath. Finally, the concentration of the outlet solution is measured as a function of time from when the feed was introduced to the adsorbent module. These measurements are often plotted as breakthrough curves. Example breakthrough curves for an aqueous acetone solution flowing... 

Various specific experiments support this general scheme. For example, in 80% aqueous acetone, the rate constant for lacemization ofp-chlorobenzhydiyl p-nitrobenzoate (/ ) and that for exchange of label in the carbonyl group can both be measured. At 100 C, kjk = 2.3. 

Similar measurements have been made for the equilibria involving acetone and its enol, 2-hydroxypropene. ... 

As the greatest accuracy is achieved in any determination by measuring the smaller component, in this case it is the acetone which is determined quantitatively rather than the propan-2-ol. 

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