The Gas Chromatographic Analysis of Sulfur Compounds and Aliphatic Amines in the Exhaust Gas from a Fish Meal Dryer and Cooker

Abstract

Two proposed sample preparation method were applied for the gas chromatographic analysis of sulfur compounds and aliphatic amines in the exhaust gas from a fish meal dryer and cooker.At least eleven sulfur compounds from a fish meal dryer and at least seven sulfur compounds from a cooker were identified including hydrogen sulfide and methylmercaptan by the use of direct cold trap method with liquid oxygen, and by flame photometric detector.The detected concentrations of representative sulfur compounds in the exhaust gas from the fish meal dryer are as follows; carbonyl sulfide 0.08ppm, hydrogen sulfide 0.91ppm, carbon disulfide 0.03ppm, methylmercaptan 0.32ppm, n-propyl mercaptan 0.40ppm, dimethyl disulfide 0.17ppm.From the cooker; carbonyl sulfide 0.03ppm, hydrogen sulfide 4.2ppm, carbon disulfide 0.02ppm, methyl mercaptan 5.2ppm, and dimethyl disulfide 0.09ppm were detected.The major component of the exhaust gas from the fish meal dryer was hydrogen sulfide, and that from the cooker was methyl mercaptan.From analysis of aliphatic amines, only trimethyl amine was detected by the use of direct cold trap method with liquid oxygen and chemical trap method with 0.1 N-hydrochloric acid aqueous solution, and by flame ionization detector.In latter case the trapped sample was decomposed with 40% sodium hydroxide aqueous solution, followed by the cold trap method.The detected concentrations of trimethylamine are as follows; 0.42ppm, for the exhaust gas from fish meal dryer and 1.0ppm for the exhaust gas from cooker.In this method of analysis, a 5.8ppm of ethanol was also detected.The concentrations ratio of trimethylamine versus hydrogen sulfide in fish meal dryer was about 0.5 : 1, and in cooker about 0.2 : 1.