Thymol crystal

A few thymol crystals are added in each bag for preservation. All of the fetuses of each species are then ready for examination. 

The characteristic odour of ajowan oil is due to the high content of thymol (61%). Thymol easily crystallizes out from the oil and is sold in Indian markets as ajowan ka-phool, or sat-ajowan, and is much valued in medicines. Thymol is used as an ingredient of deodorants, mouthwashes, toothpastes and many pharmaceutical preparations. The leftover residue after distillation contains 15-17% protein and 20-25% fat and is valued as cattle feed. The major processed products are ajowan oil, oleoresin, thymol, thymol crystals, dethymolized oil (thymene) and fatty oils (Malhotra and Vijay, 2004). 

Sterilization is easily accomplished by placing the books in an airtight container and supporting them in such a way that the leaves are fanned out—this is important because penetration between the leaves is essential. A tray of thymol crystals (50 g/m3) is placed close to a 40-watt electric lamp, the heat from which is sufficient to vaporize the crystals. The lamp is switched on for about two hours daily for a week. The chamber should have a glass front so that the position of the books and the vaporization of the thymol can be checked. All materials are safe under this treatment with the exception of oil paints and varnishes and silk-screen printing inks, which are softened. 

Thymol,—This furnishes a not unpleasant, and very useful antiseptic soap, recommended especially for the cleansing of ulcerated wounds and restoring the skin to a healthy state. The normal strength is 3 per cent. It is preferable to replace part of the thymol with red thyme oil, the thymene of which imparts a sweeter odour to the soap than if produced with thymol alone. A suitable blend is 2 per cent, of thymol crystals and per cent, of a good red thyme oil. 

To prepare the standard pH buffer solutions recommended by the National Bureau of Standards (U.S.), the indicated weights of the pure materials in Table 8.15 should be dissolved in water of specific conductivity not greater than 5 micromhos. The tartrate, phthalate, and phosphates can be dried for 2 h at 100°C before use. Potassium tetroxalate and calcium hydroxide need not be dried. Fresh-looking crystals of borax should be used. Before use, excess solid potassium hydrogen tartrate and calcium hydroxide must be removed. Buffer solutions pH 6 or above should be stored in plastic containers and should be protected from carbon doxide with soda-lime traps. The solutions should be replaced within 2 to 3 weeks, or sooner if formation of mold is noticed. A crystal of thymol may be added as a preservative. 

PI. Saturated potassium hydrogentartrate solution. The pH is insensitive to changes of concentration and the temperature of saturation may vary from 22 to 28 °C the excess of solid must be removed. The solution does not keep for more than a few days unless a preservative (crystal of thymol) is added. 

Maximum suppressors. Gelatin is widely used as a maximum suppressor in spite of the fact that its aqueous solution deteriorates fairly rapidly, and must therefore be prepared afresh every few days as needed. Usually a 0.2 per cent stock solution is prepared as follows. Allow 0.2 g of pure powdered gelatin (the grade sold for bacteriological work is very satisfactory) to stand in 100 mL of boiled-out distilled water for about 30 minutes with occasional swirling warm the flask containing the mixture to about 70 °C on a water bath for about 15 minutes or until all the solid has dissolved. The solution must not be boiled or heated with a free flame. Stopper the flask firmly. This solution does not usually keep for more than about 48 hours. Its stability may be increased to a few days by adding a few drops of sulphur-free toluene or a small crystal of thymol, but the addition is rarely worth while and is not recommended. 

Crystal violet Thymol blue 2,4-Dinitrophenol Bromophenol blue Bromocresol green Methyl red Alizarin Bromothymol blue Phenol red Phenolphthalein Alizarin yellow R... 

Cresol red Crystal Violet Malachite Green Methanil Yellow Thymol Blue Orange IV -2,4-Dinitrophenol -Erythrosin, Na2 salt -Dimethyl Yellow Cl 11020 Bromophenol Blue Congo Red Cl 22120 Methyl Orange Bromocresol Green Alizarin Red S Cl 42750 Methyl Red Cl 13020 -Bromocresol Purple Chlorophenol Red p-Nitrophenol Alizarin Bromothymol Blue Brillant Yellow Phenol Red Neutral Red Cl 50040 -m-NItrophenol -Cresol Red Metacresol Purple Phenolphthalein -Thymolphthalein -P-Naphthyl Violet Alizarin Yellow R 2,4,6-T rinitrotoluene... 

Besides thymol, other terpenes have been tested for their toxicity against Varroa jacobsoni. Imdorf et al. determined in vitro the effective miticidal air concentrations, but with minimal effects on the bees as follows 5-15 pg/litre air for thymol, 50-150 pg/litre for camphor and 20-60 pg/litre for menthol 1,8-cineole was too toxic for honey bees [86], Another interesting paper considered the efficacy of different isomers of menthol on Acarapis woodi [87]. The natural crystals obtained from the plant, synthetic crystals and the L-form gave more than 96% mite mortality, while the D-form crystals only a 37% mortality. 

Colorless, hexagonal crystals with an ethereal odor, easily soluble in alcohol, ether, and chloroform, but difficultly soluble in water (1 1100). Thymol melts at 50 to 51° C., and boils at 228 to 230° C. 

Camphor [126-04-5] (11), menthol [89-78-1] (12), and thymol [89-83-8] (13) are used in topical over-the-counter cough and cold preparations. Camphor is isolated from the camphor tree, Cinnotnotnutn catnphora T. Nees Ebemeier, or prepared synthetically from a-pinene or isobomeol. About 75% of the camphor sold in the United States is synthetic. Menthol, commercially the most important terpene alcohol, is obtained by crystallization from... 

It has been reported that a crystal of thymol in the stock solution will inhibit bacterial growth [63b] this preservation technique is recommended only when standard solutions are prepared free of acid. Solution stability is a function of nature of analyte and matrix and their concentrations, acid concentration, type of storage container, storage conditions, etc. At extremely low concentrations, contamination from solvents, water and containers must be considered. 

Acetoxymercuri thymol occurs as small, lustrous crystals, M.pt. 163° C., decomposing at 178° to 180° C. The bromide is a white com-pornid, M.pt. 149° C. with decomposition sulphate, amorphous powder, decomposing at 235° C. nitrate, white powder, M.pt. 167° C. with decomposition oxide, white po vder, blackening at 180° C., and decomposing about 205° C. hydroxide, M.pt. 190° to 195° C. with decomposition. 

Thymol occurs as colorless or often large translucent crystals, or as a white crystalline powder with a herbal odor (aromatic and thyme-like) and a pungent caustic taste. 

Phenyl Salicylate. Phenyl salicylate, salol. occurs as fine white crystals or a white crystalline powder with a characteristic taste and a faint, aromatic odor. It is insoluble in water (1 6.700). slightly soluble in glycerin, and soluble in alcohol (1 6). ether, ehlorofomi. aeetone. or fixed and volatile oils. Dump or eutectic mixtures form readily with many organic material.s. such as thymol, rtrcnthol. camphor, chloral hydrate, and phenol. 

Thymol is present in volatile oil of thyme and ajowan, mint seeds from which it may be extracted with sodium hydroxide, liberated from the sodium compound with acid and purified by crystallization. It has a woody, burnt, smoky odor. 

Orndorff and Cornwell state that thymol blue can be re-crystallized from ether or glacial acetic acid. Its solubility in acetone, chloroform, carbon tetrachloride, benzene, toluene, xylene, and ethyl acetate is too small. 

The original report of Kolthoff (l.c. 1925) contained also a description of a series of mixtures obtained from 0.05 molar succinic acid and 0.05 molar borax, the pH of which varies between 3.0 and 5.8. They will not be discussed since they offer no advantage over the monocitrate mixtures. A minute crystal of thymol prevents the growth of fungi in the citrate mixtures during storage. 

C10H14O, Mr 150.22, pioi.3kPa 232.5 °C, df 0.9756, n53° 1.5227, is the main constituent of thyme and some origanum oils it also occurs in many other essential oils. It forms colorless crystals (mp 51.5 °C) with a spicy-herbal, slightly medicinal odor reminiscent of thyme. Thymol is prepared on a technical scale in a continuous high-temperature, high-pressure, liquid-phase, ort/io-alkylation process, from m-cresol and propylene, in the presence of activated aluminum oxide hydrate [163a],... 

Carbonate, C21HM03, white crystals thymol odor volatil -jzes with steam, mp 49. Insol in water, acids, alkalies. Sol in hot alcohol, chloroform, ether, carbon tetrachloride. 

Isopropyl-3-methyl-4-thiocyanatophenol 13 Thymol (15 g) and NaSCN 2H20 (35 g) are dissolved in methanol (150 ml) saturated with NaBr. Bromine (20 g) in methanol (30 ml) saturated with NaBr is added to this solution at room temperature with stirring. After 30 min a six- to eight-fold amount of water is added, whereupon the product separates as an oil. This crystallizes in 2 h at 0°, is dried on porous plate, and after recrystallization with charcoal from light petroleum has m.p. 105° (yield 95 %). 

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