Rapid and precise methods have been studied for the determination of microamounts of lead in fatty oils, fatty acids and their derivatives. The sample was carbonized with sulfuric acid by heating in the range of 250° to 280°C, and then 30% hydrogen peroxide was gradually added to destroy organic matter. By Applying this method, the digestion was carried out rapidly as compared with conventional methods such as dry ashing and wet digestion. Lead in the digested solution obtained was determined by spectrophotometric determination and atomic absorption spectrometry. In the former method, lead was extracted as dithizone complex from the digested solution, and then the extract was determined spectrophotometrically by using the maximum absorbancy at 520nm. In the latter method, complex produced by adding sodium diethyldithiocarbamate was extracted with methyl isobutyl ketone. The extract was directly injected into an air-hydrogen or air-acetylene flame, and a spectral line of lead was measured at 283.3nm. The proposed methods were tested by carrying out collaborative studies on samples which had been artificially prepared by adding known amounts of lead to soybean oil. The results obtained corresponded to a satisfactory agreement with the theoretical values.
Ethyl caproate was pyrolyzed at 450, 500, 550, 600 and 650°C, respectively. Each component of the products was analyzed in detail, and the quantitative change in each component due to pyrolysis temperature was clarified. The thermal decomposition of ethyl caproate increased in amount with the rise of temperature. The tendency was very similar to that in the case of ethyl acetate. The temperature at which the pyrolysis gets to the maximum of more than 90% is 600°C in the case of ethyl acetate, and 550°C in the case of ethyl caproate. From the experiment, it is shown that ethyl caproate is easily decomposed at the lower temperature than ethyl acetate. The principal products in the pyrolysis of ethyl caproate were carbon monoxide, methane, ethane, ethylene, propane, propylene, carbon dioxide, caprone (diamyl ketone), caproic acid and C5-compounds. Among these products, caproic acid and ethylene showed a remarkable increase in amount with the rise of the pyrolysis temperature. Especially, ethylene showed an extraordinary increase in amount at 600°C. C5-compounds showed a slow decrease in amount with the rise of the pyrolysis temperature. On the contrary, carbon monoxide, methane, ethane and propane showed a remarkable decrease in amount at 600°C. Carbon dioxide, propylene and caprone were almost temperature-independent.
The gas-liquid chromatographic characteristics of 4 kinds of Δ4-stenol (Δ4-cholestenol, 4-methyl-Δ4-cholestenol, 6α-methyl-Δ4-cholestenol, 6β-methyl-Δ4-cholestenol) and also their acetoxy, trifluoracetoxy and trimethylsiloxy (TMS) derivatives have been studied. The Δ4-stenols and their derivatives gave two peaks (a and b) which have retention times significantly shorter than would be expected from comparison to other sterols. On the TMS derivatives, the third peak (c) which is less volatile component was also observed. Peak a, b and c were respectively identified to Δ2, 4-diene, Δ3, 5-diene and the original TMS derivative by means of preparative GLC, UV, IR and gas chromatography-mass spectrometry. These results suggested that the Δ4-stenols and their derivatives underwent a thermal elimination reaction of functional group at c-3, and yielded unsaturated hydrocarbons (a and b). The structure of resulting hydrocarbons was not affected by the nature of a methyl group in proximity to the Δ4-bond.
N-Alkyldiethylenetriamines react with Cu2+ in dilute aqueous solution to form complexes which show good forming ability. The molar ratio of alkylpolyamine to Cu2+ in each complex was determined to be almost 1 : 1 by means of visible absorption spectroscopy. These chelate compounds showed slight pH dependence on the absorbance of absorption spectra and also on the results of foam treatments. The most suitable conditions, i.e., pH of the solution and the amounts of the agents to be added on the form treatment, were found to be closely related to the results of absorption spectra.
The effect of additional salt on the critical micelle concentration (cmc) of the sodium sulfoalkyl alkanoates was examined by the change of absorption spectra of pinacyanol chloride. The cmc of the surfactant decreased with increase of addition of sodium chloride, and the logarithm of the cmc was a linear function of the logarithm of total concentration of counter ion. These results were expressed as follows : 1) logcmc=0.55logC-2.47 for C9H19COO (CH2) 2SO3Na 2) logcmc=0.59logC-2.75 for C9H19COO (CH2) 3SO3Na 3) logcmc=0.63logC-3.06 for C9H19COO (CH2) 4SO3Na 4) logcmc=0.59logC-3.24 for C10H21COO (CH2) 3SO3Na 5) logcmc=0.56logC-3.44 for C11H23COO (CH2) 2SO3Na 6) logcmc=0.60logC-3.78 for C11H23COO (CH2) 3SO3Na 7) logcmc=0.64logC-4.05 for C11H23COO (CH2) 4SO3Na The slope of these equations increased with the change of position of the ester group from position near the terminal sulfonate to more central positions of surfactant molecule. These phenomena indicate that the change of cmc with addition of salt was influenced by the position of the ester group in the surfactant molecule. The dependency of cmc lowering by salt addition to the position of ester group in surfactant molecule will be attributed to the change in counterion binding on micelle surface and also to the change in hydrophobic bond with the position of ester group.
The critical micelle concentration (cmc) values of seven sodium sulfoalkyl alkanoates, CnH2n+1 COO (CH2) mSO3Na, with the number of carbon atoms n=9, 10 and 11; m=2, 3 and 4 in the ethanol-water mixture were measured by the spectral change of pinacyanol chloride. The cmc values of n=9 derivative series decreased linearly with the increase of ethanol concentration. While the cmc values of n=10 and 11 derivative series showed a minimum and then increased markedly with the ethanol concentration. These phenomena suggest that the decrease of cmc is due to partly solubilized ethanol in the micelle of the surfactant, and that the increase of cmc is due to the increased solvent power of ethanol-water mixture solvent. The results indicated that the effect of ethanol-water mixture solvent on the cmc value is greatly dependent on the position of the ester group in the alkyl chain of the surfactant. Namely, the cmc decreasing-power of the methylene unit situated between the ester and sulfonate group is more than that of the methylene unit in the fatty acid portion. On the other hand, the effect of variation of alkyl chain length in the fatty acid portion was more than that of alkyl chain length situated between the ester and sulfonate group on the cmc increasing-power.
Four new sulfonates containing two or three chlorophenol units joined by methylene group were prepared and tested for surface activity, and antibacterial and antimildew properties. The results obtained were as follows : (1) The three-ring polychlorophenol sulfonates were superior to the corresponding two-ring compounds both in surface activity and in antimildew property. (2) Number of the chlorophenol rings, however, had no significant effect on bactericidal activity. (3) Introduction of a chlorine atom into the ortho position to the terminal phenolic hydroxyl group reduced both bactericidal and antimildew activities, but introduction of one more chlorine atom into the meta position enhanced both the activities.
A simple apparatus for the determination of carbonate is developed. Carbon dioxide is liberated from carbonates by hydrochloric acid in a sealed glass reactor. Head space gas in the reactor containing air and carbon dioxide is directly introduced into separating column with 4-way cock, and detected with thermal conductivity detector. Digital integrator is used for measuring the peak area of carbon dioxide. Volume of the reactor cell, inject-time (which is the most important factor for determining carbon dioxide in this apparatus.) and some other operating conditions are discussed. Thus, under the optimum conditions, accurate and reproducible data were obtained more rapidly (within 10 minutes) in comparison with other conventional methods. This technique is particularly applicable to the determination of sodium carbonate in heavy duty detergents.