IODINASI ESTER ETIL ASAM LEMAK MINYAK CANDU

• Main Author: Soenarjo, Sunarhadijoso
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/886
• Institution: Institut Teknologi Bandung

Several kinds of poly-iodo organic compounds can be used as contrast media for roentgenography diagnosis due to the opacity of the iodine atom. Poppy seed oil, isolated from the seed of Papaver sqmniferum Linne, has been known for having unsaturated bonds. Therefore, the addition of the iodine is expected to give a poly-iodc organic compound which can be used for the above mentioned purpose. However, since the oil has a high viscosity, it must be changed into its simple ester prior to the iodination. For this reason, the ail was hydrolyzed in the presence of a strong base and the produced soap was then acidified. The collected fatty acid was reacted with excess ethanol under nitrogen pressure in an azeotropic esterification system using concentrated sulphuric acid as catalyst. The separation of the fatty acid and the ethyl ester were carried out by means of diethylether extraction. The chemical yields of the hydrolysis and esterification process were more than 97 % (male/mole) and more than 91 . (gig) respectively. Determination of iodine number showed that there was no significant change in the double bonds of the alkyl chains. The saponification value had also shown that the average molecular weightagreed with the corresponding theoretical calculation. For incorporating iodine to the ethyl ester, an addition process using Iz labelled with 131I has been tried, but the obtained yield was too low. As the iodobromination of unsaturated fatty acid or oil can be performed quantitatively, this process was carried out followed by exchange reaction with Iz in chloroform. The iodobrominated compound and its exchange product were separated by means of solvent extrac=tion in which the excess of the iodine-was reduced by sodium thiosulphate solution. The iodine and the bromine content were determined by Neutron Activation Analysis as 12®I and e Br respectively. But the content of the iodine did not agree with that of the bromine. Among other things, it might be caused by the instability of the compounds and the difference of the statistics in counting for 12®I and E\'wBr. It can be stated that the exchange between Br in the iodobrominated compound and I in the Iz could proceed well in chloroform. However, it is not a certainty that the desired iodo-organic compound can be obtained . Ultra-violet spectrophctometric determination showed a red shift of the carbonyl group caused by the alkyl and/or alkyl ester groups. It was also observed that the ultraviolet absorption properties of I bore a slight likeness to that of Br .