Determination of iodine values using 1,3-dibromo-5,5-dimethylhydantoin (DBH) without the employment of chlorinated hydrocarbons. Analytical methods of pharmacopoeias with DBH in respect to environmental and economical concern. Part 17.
Low and medium iodine values of fixed oils and fats can be determined in glacial acetic acid within reduced waiting times of only 5 min. Highly unsaturated compounds such as those of linseed oil, cod-liver oil, sunflower oil, soybean oil, wheat germ oil and the emulsifier sorbitan trioleate result too low values in comparison to PH. EUR. 2002 [2] and USP 2000 [3]. Cocoa butter with a low iodine number is insoluble in glacial acetic acid. The iodine values of nonionogenic emulsifiers such as ceteareth-30 (Macrogol cetostearyl ether PH. EUR. 2002), oleth-10 resp. 20 (Macrogol oleyl ether PH. EUR. 2002) and polysorbate-80 PH. EUR. 2002 are obtained in aqueous solutions. Oleth-2 (Macrogol oleyl ether PH. EUR. 2002), polyoxyl-40 castor oil (Macrolglycerol ricinoleate PH. EUR. 2002), polysorbate-60 PH. EUR. 2002 and sorbitan trioleate PH. EUR. 2002 need the addition of ethyl acetate. Fixed oils even with high iodine values can be determined in an o/w emulsion with a reaction time of 5 min in most cases, when nonionogenic emulsifiers such as ceteareth-30, polyoxyl-30 glycerol monolaurate or polyoxyl-60 hydrogenated castor oil (Macrolglycerol hydroxystearate PH. EUR. 2002) are used.
Hilp
M
M
Institut für Pharmazeutische Chemie, Philipps-Universität, Marburg, Germany. Hilp@mailar.uni-marburg.de
D000085:Acetates / Q000737:chemistry; D004655:Emulsions; D004787:Environmental Pollution / Q000517:prevention & control; D005060:Europe; D006827:Hydantoins / Q000737:chemistry* / Q000191:economics; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry; D007202:Indicators and Reagents; D007455:Iodine / Q000032:analysis*; D009821:Oils / Q000032:analysis; D010602:Pharmacopoeias as Topic; D011199:Potentiometry; D012997:Solvents; D013501:Surface-Active Agents
D000085:Acetates; D004655:Emulsions; D006827:Hydantoins; D006843:Hydrocarbons, Chlorinated; D007202:Indicators and Reagents; D009821:Oils; D012997:Solvents; D013501:Surface-Active Agents; D007455:Iodine; C056578:1,3-dibromo-5,5-dimethylhydantoin