Using 30 percent hydrogen peroxide as the oxidant,the oxidation reaction of cyclohexanone to adipic acid catalyzed by Na2WO4·2H2O in the presence of acid ligands was investigated.The reaction follows the coordina...Using 30 percent hydrogen peroxide as the oxidant,the oxidation reaction of cyclohexanone to adipic acid catalyzed by Na2WO4·2H2O in the presence of acid ligands was investigated.The reaction follows the coordination catalysis mechanism.Both the acidity and the structure of the acid ligand had a notable effect on the catalytic ability of the catalytic system.By using sulfosalicylic acid as acidic ligand and the mole ratio of sulfosalicylic acid to Na2WSO4·2H2O was 1/1,the intermediate products of the catalytic oxidation reaction were analyzed by the GC-FTIR technique.the result showed that ε-caprolactone was the important stable intermediate product of the reaction.The possible mechanism was proposed.The cyclohexanone was oxidized by hydrogen peroxide to ε-caprolactone in the first step based on the Baeyer-Villiger oxidation mechanism,then the product from the rapid hydrolization of ε-caprolactone is oxidized to adipic acid.展开更多
Milk fat contains a variety of nutritive and health-promoting compounds that guard against some disease. In the current system of global competition, when the quality of milk and milk products is not an option but rat...Milk fat contains a variety of nutritive and health-promoting compounds that guard against some disease. In the current system of global competition, when the quality of milk and milk products is not an option but rather a requirement, therefore, determining the purity of milk fat is critical. This study aims to validate analytical methods for detecting palm oil in a mixture of milk fat and palm oil. Methods of this study was involved detection of non-milk fat in fat blinders by determining the saponification value, iodine number, refractive index, butyro refractometer reading, Gas chromatography, Reverse Phase High-performance liquid chromatography, and Fourier transforms Infrared. The results of this study revealed that the saponification value, Iodine number, refractive index, and Butyro Reading could be used to detect the addition of palm oil by a level of 10% - 20% or more to the milk. The level of some fatty acids in the milk as determined by GC, such as myristic acid (C14:0), palmitic acid (C16:0), and stearic acid (C18:0), is correlated well with the level of adding palm oil to milk fat. The determination of cholesterol and β-sito-sterol content by RP-HPLC could be used for the detection of the addition of palm oil to milk fat. The spectrum behavior produced by FTIR spectroscopy in this adulterated sample is almost the same, so this technique could not be used to detect the palm oil in milk fat.展开更多
文摘Using 30 percent hydrogen peroxide as the oxidant,the oxidation reaction of cyclohexanone to adipic acid catalyzed by Na2WO4·2H2O in the presence of acid ligands was investigated.The reaction follows the coordination catalysis mechanism.Both the acidity and the structure of the acid ligand had a notable effect on the catalytic ability of the catalytic system.By using sulfosalicylic acid as acidic ligand and the mole ratio of sulfosalicylic acid to Na2WSO4·2H2O was 1/1,the intermediate products of the catalytic oxidation reaction were analyzed by the GC-FTIR technique.the result showed that ε-caprolactone was the important stable intermediate product of the reaction.The possible mechanism was proposed.The cyclohexanone was oxidized by hydrogen peroxide to ε-caprolactone in the first step based on the Baeyer-Villiger oxidation mechanism,then the product from the rapid hydrolization of ε-caprolactone is oxidized to adipic acid.
文摘Milk fat contains a variety of nutritive and health-promoting compounds that guard against some disease. In the current system of global competition, when the quality of milk and milk products is not an option but rather a requirement, therefore, determining the purity of milk fat is critical. This study aims to validate analytical methods for detecting palm oil in a mixture of milk fat and palm oil. Methods of this study was involved detection of non-milk fat in fat blinders by determining the saponification value, iodine number, refractive index, butyro refractometer reading, Gas chromatography, Reverse Phase High-performance liquid chromatography, and Fourier transforms Infrared. The results of this study revealed that the saponification value, Iodine number, refractive index, and Butyro Reading could be used to detect the addition of palm oil by a level of 10% - 20% or more to the milk. The level of some fatty acids in the milk as determined by GC, such as myristic acid (C14:0), palmitic acid (C16:0), and stearic acid (C18:0), is correlated well with the level of adding palm oil to milk fat. The determination of cholesterol and β-sito-sterol content by RP-HPLC could be used for the detection of the addition of palm oil to milk fat. The spectrum behavior produced by FTIR spectroscopy in this adulterated sample is almost the same, so this technique could not be used to detect the palm oil in milk fat.
