Fishy

Trimethylamine, CjH N, (CH3J3N. Colourless liquid with a strong fishy odour, miscible with water, m.p. — I24 C, b.p. 3-5°C. It occurs naturally in plants, herring brine, bone oil and urine. It reacts with hydrogen peroxide to give trimethylamine oxide and with ethylene oxide to give choline its commercial importance stems chiefly from this latter reaction. 

Place about i g. of the base in a test-tube, and cover with concentrated (about 20%) sodium hydroxide solution. Bring the mixture gently to the boil, keeping the test-tube lightly closed with the finger meanwhile to prevent undue escape of vapour.. A.s the solution boils a strong fishy odour of dimethylamine is detected, and white fumes form when the test-tube is held near an open bottle of concentrated... 

Methylamine evolved (fishy odour, alkaline reaction). 

Physical Properties, (i) Triethylamine, b.p. 90 , tri-n-propylamine, b.p. 156 , tri biitylamine, b.p. 212 ", are liquids with a fishy odour, and with decreasing solubility in water. 

A collection of physical prop erties of some representative amines is given in Appendix 1 Most commonly encoun tered alkylamines are liquids with unpleasant fishy odors... 

Odors are characterized by quaUty and intensity. Descriptive quaUties such as sour, sweet, pungent, fishy, and spicy are commonly used. Intensity is deterrnined by how much the concentration of the odoriferous substance exceeds its detection threshold (the concentration at which most people can detect an odor). Odor intensity is approximately proportional to the logarithm of the concentration. However, several factors affect the abiUty of an individual to detect an odor the sensitivity of a subject s olfactory system, the presence of other masking odors, and olfactory fatigue (ie, reduced olfactory sensitivity during continued exposure to the odorous substance). In addition, the average person s sensitivity to odor decreases with age. 

Inhalation of aerosols or heated vapors may result in irritation of the nose, throat, and upper respiratory system. Lower molecular weight and branched-chain amines are more volatile and can cause irritation if inhaled. Volatile amines are easily recognized by their unpleasant, fishy odor. 

Polyunsaturated fatty acids in vegetable oils, particularly finolenic esters in soybean oil, are especially sensitive to oxidation. Even a slight degree of oxidation, commonly referred to as flavor reversion, results in undesirable flavors, eg, beany, grassy, painty, or fishy. Oxidation is controlled by the exclusion of metal contaminants, eg, iron and copper addition of metal inactivators such as citric acid minimum exposure to air, protection from light, and selective hydrogenation to decrease the finolenate content to ca 3% (74). Careful quality control is essential for the production of acceptable edible soybean oil products (75). 

Observable Characteristics - Physical State (as normally shipped) Liquid Color Coiorless Odor. Miid ammoniacai faint, fishy characteristic. 

Observable Characteristics - Physical State (as shipped) Liqui, Color Colorless Odor. Fishy. Physical and Chemical Properties - Physical State at 15 X and 1 atm. liquid Molecular Weight 101.19 Boiling Point at 1 atm. 193.1, 89.5, 362.7 Freezing Point -174.5, -114.7, 158.5 Critical Temperature 504, 262, 535 Critical Pressure 440, 30, 3.0 Specific Gravity 0.729 at 20 X fliquidj Vapor (Gas) Specific Gravity 3.5 Ratio of Specific Heats of Vapor (Gas) 1.055 Lateru Heat of Vaporization 140,80,3.3 Heat of Combustion -17,040, -9,466, -369.3 Heat of Decomposition Not pertinent. 

Odors possess many classifications. There are 20 of them commonly used, all possessing rather picturesque names. In fact the names, in many cases, are far more pleasant than the odors themselves. To name a few of them - nasturtium, cucumber, geranium, fishy, pigpen, earthy, grassy and musty. Authorities further classify these odors in terms of their intensity from very faint, faint, distinct and decided... 

Aromatic, Fishy, Earthy, or Woody Smell a) Activated carbon type filter, or... 

Prodromi of anaphylaxis comprise metallic fishy taste, anxiety, sweating, headache, disorientation. Autopsy cases have shown few specific findings sometimes there is inflation of the lung and pulmonary edema with peribronchial eosinophilic... 

C05-0147. Elemental analysis of an organic liquid with a fishy odor gives the following elemental mass... 

A fishy odor before or after addition of 1 0% potassium hydroxide (i.e., "whiff" test)... 

Offensive fishy-smelling vaginal discharge Signs... 

Release of a fishy odor upon the addition of an alkali (10% potassium hydroxide) to a vaginal sample... 

Odor Fruity odor in high concentrations smells like soft soap with a fishy smell in low concentrations. 

When someone buys fresh fish, they often smell the fish to test for freshness—the fresher the fish, the less fishy the smell. What is the source of the fishy odor ... 

To remove a fishy smell, wash with a solution of baking soda, lemon juice, or mild vinegar. Why These substances act as acids to neutralize the amines, which are alkaline (basic) substances. 

Oily fishmeal is allowed in organic rations and it has an even higher essential amino acid content than full-fat soya. However, its use in poultry rations is limited partly by cost, restrictions on the source of the fishmeal imposed by organic standards, the fact that some customers demand birds that are fed on a vegetable-based diet and concerns about fishy taints to the product (Walker and Gordon, 2001). 

DNPT is a free flowing light yellow powder. Alone DNPT decomposes at approximately 190 °C and produces 265 cm3 of gas per gram at STP. Nitrogen, nitrous oxide, various amines and water are produced. In a rubber environment the gas generation takes place within a range of 130-190 °C. A characteristic amine fishy odour is quite pronounced and can be offensive for some applications. DNPT is non-staining. 

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