• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.144-150
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• 2000

The present study was peformed to determine the hydrolysis rate constants and degradation products of phosphamidon and proffnofos by the OECD method. Hydrolysis rate constants of phosphamidon in pH 4, pH 7, and pH 9 buffer solutions at 25 and 40$^{\circ}$C were 0.0020, 0.0022, 0.0049 and 0.0040, 0.0050, 0.0150, respectively. Hydrolysis rate of phosphamidon was accelerated by temprerature change under same pH conditions, and half-life of phosphamidon in pH 9 at 40。C was 3 times faster than that at 25。C. Hydrolysis rate of phosphamidon in alkaline solution(pH 9) was 2~4 times faster than that in acidic solution(pH 4) and neutral solution(pH 7) under same temperature. Hydrolysis rate constants of profenofos in pH 4, pH 7, and pH 9 buffer solutions at 25 and 40。C were 0.0022, 0.0047, 0.0860 and 0.0035, 0.0086, 0.1245, respectively. Hydrolysis rate of profenofos was accelerated by temprerature change under same pH conditions. Hydrolysis rate of profenofos in alkaline solution(pH 9) was 15~40 times faster than in acidic solution(pH 4) and neutral solution(pH 7) under same temperature condition, and half-life of profenofos was very fast within 8 hours. The hydrolysis rate of profenofos was faster than that of phosphamidon. In order to identify hydrolysis products, the extracts of degradation products were analyzed by GC/MS. The mass spectra of hydrolysis products of phosphamidon were at m/z 153 and 149, those of the profenofos were at m/z 208 and 240, respectively. The hydrolysis products of phosphamidon were O, O-dimethyl phosphate(DMP) and N, N-diethylchloroacetamide, and those of profenofos were 4-bromo-2-chlorophenol and O-ethyl-S-propyl phosphate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.307-312
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• 1984

The dried pure shells deprived of soft tissues were subjected to analysis of chitin-protein complexes from 5 species of marine crustaceans, including 2 species of crabs and 3 species of shrimps. The protein fractions were obtained from chitin-protein complexes under the varying conditions of extractions and the crude chitin was prepared from the shells by the sulfurous acid process. The crude chitin was purified through the extraction with several organic solvents such as dimethyl-acetamide, N-methylpyrrolidone. The purified chitin was also examined using the phase contrast microscope. Total protein contents of the shells were diverse, showing 9.6% for Portunus trituberculatus, 3.1%, Charybdis bimaculata, 9.4%, Penaeus japonicus, 10.9%, Metapenaeus intermedius and 5.8%, Squilla oratoria. Covalently bound protein varied with species from 2.1% for Charybdis bimaculata to 9.9% for Metapenaeus intermedius. The puified chitin contents of the shells were shown to 21.1% for Portunus tritube rculatus, 6.2%, Charybdis bimaculata, 20.2%, Penaeus japonicus, 27.1%, Metapenaeus intermedius and 25.5%, Squilla oratoria. Exceptionally low analytical value obtained with Charybdis bimaculata are supposed to be due to the very young subjects. The ratios of chitin to covalently bound protein in the shells were various such as 2.7 to 1 for Portunus trituberculatus, Penaeus japonicus and Metapenaeus intermedius, 3.1 to 1, Charybdis bimaculata and 6.1 to 1, Squilla oratoria. The microscope finding of the purified chitin showed the filamentous form in all the specimen.