Permanent yellow

Sylvestrene tetrabromide, CjoHjf.Br, is prepared when pure sylvestrene, regenerated from its ihydrochloride and dissolved in acetic acid, is heated with bromine until a permanent yellow colour is produced. Water is added to the reaction product, but not sufficient to precipitate the bromide, and the vessel allowed to stand in a cold place. The bromide separates and can be purihed by recrystallisation from alcohol. It forms mono-symmetric crystals melting at 135° to 136°, and having a specihc rotation -t- 73 7°. 

Permanent-gelb, n. permanent yellow, -rot, n. permanent red, red toner. -weUs, n. permanent white. 

If the patient wears soft contact lenses, a permanent yellow stain of the lenses may occur. It is a good idea to seek the advice of an ophthalmologist regarding corrective lenses while taking this drug. 

Permanent shape, of shape-memory polymer, 22 355-356, 357 Permanent wet drum separators, 15 443 Permanent wet-strength resins, in paper manufacture, 18 115-116 Permanent Yellow FGL, pigment for plastics, 7 366t... 

Synonyms lemon yellow permanent yellow C.I. Pigment yellow 31 Baryta yellow ultramarine yellow C. I. 77103 Steinbuhl yellow. 

Bone. Although bone is a relatively inert tissue, it can accumulate such substances as tetracyclines, lead, strontium, and the antitumor agent cisplatin. These substances may accumulate in bone by absorption onto the bone crystal surface and eventually be incorporated into the crystal lattice. Tetracycline deposition during odontogenesis may lead to a permanent yellow-brown discoloration of teeth, dysplasia, and poor bone development. Lead can substitute for calcium in the bone crystal lattice, resulting in bone brittleness. Bone may become a reservoir for the slow release of toxic substances, such as lead and cisplatin. 

A sample (approximately 0.2 g.) is weighed accurately and dissolved in 25 ml. of water then 25 ml. of 0.1 N hydrochloric acid and 0.2 g. of potassium bromide are added. The solution is titrated with 0.017 M potassium bromate until a permanent yellow color is produced. Potassium iodide (0.1 g.) is added, and the solution is backtitrated to a starch end point with 0.1 N sodium thiosulfate. The blue color returns in about a minute since the high acidity promotes air oxidation of excess iodide. The accuracy is only slightly less if the appearance of a faint yellow bromine color is taken as the end point. One mole of potassium bromate is equivalent to 3 of sodium /8-styrenesul-fonate. 

Very marked degradation is evident for solutions of tetrachloro- a-ketodihydronaphthalene in carbon tetrachloride. Room temperature irradiation with short exposures gives a red solution which reverts in several minutes, whereas long exposures generate a permanent yellow color assigned to a dimer (60). 

When isomerization of 100-g. batches of non-conjugated ketone was effected in ethanol under catalysis by either hydrochloric acid or sodium hydroxide (followed by neutralization of the yellow enolate solution with acetic acid), a permanent yellow coloration developed, the first-crop material was yellowish and melted at 78-80°, and the second-crop material was very impure. 

This is based on the reaction shown in Scheme 4.1. Diazomethane is prepared by decomposing N-nitroso-N-methylurea, N-nitroso-N-methyl-p-toluenesulphonamide or other substances with a similar configuration with a lye solution. An ethereal solution of diazomethane is added gradually to an ethereal solution of the sample until a permanent yellow colour is obtained [14]. To prepare diazomethane solutions, Fales et al. [15] used the apparatus shown in Fig. 4.1, available commercially in two sizes 1 mmol... 

Nessler s solution is conveniently prepared by dissolving 62 5 grams of potassium iodide m 250 c.c. water and adding to a cold, saturated solution of mercuric chloride until a faint permanent precipitate is obtained. Add 150 grams of potassium hydroxide in 150 o.e. of water, and finally a sufficient quantity of mercuric chloride solution to cause a slight, permanent, yellow precipitate. Dilute to one litre. 

Unsaturated Compounds Add, dropwise, a 1 100 (v/v) solution of bromine in carbon tetrachloride to 10 mL of sample in a glass-stoppered tube until a permanent yellow color appears, and allow to stand in a dark place for 18 h. No turbidity or precipitate forms. 

SYNS BARIUM CHROMATE (1 1) BARIUM CHROMATE OXIDE BARYTA YELLOW CHROMIC ACID, BARIUM SALT (1 1) D C.I, 77103 C.I. PIGMENT YELLOW 31 LEMON CHROME LEMON YELLOW PERMANENT YELLOW STEINBUHL YELLOW ULTRAMARINE YELLOW... 

PERMA KLEER TETRA CP see EIVOOO PERMA KLEER 50, TRISODIUM SALT see TNL250 PERMANENT WHITE see ZKAOOO PERMANENT WHITE see BAPOOO PERMANENT YELLOW see BAK250 PERMANGANATE of POTASH (DOT) see PLPOOO PERMANGANATE de POTASSIUM (FRENCH) see PLPOOO... 

Tungsten trioxide may be used as a yeUow colouring matter in the ceramic industry, since permanent yellow glazes can be produced by fusion at 800° C. vnth lead silicate, -vwth bismuth oxide, or with a mixture of zinc borate and silicate. ... 

Bromine.—Add bromine-water to 2 cc. of the egg-white solution until a permanent yellow color is formed. 

Solvents. Tetrahydrofuran (THF). THF (Dupont) was distilled in a simple distillation setup, which had been flamed out under argon. To 1500 ml of the THF, which was passed through molecular sieves, we added 20 ml. styrene and enough 1.5N butyllithium solution in hexane to give a permanent yellow collor. A small forerun was discarded, and the THF distilled directly into 28-oz bottles, which were capped and pressured with argon. 

Place a white titrating plate or a cloth towel under the flask and titrate this solution to the first permanent yellow color. This will serve as the blank. It will take only a few mL, so be careful. 

Very carefully titrate this solution until it turns a permanent yellow. Record the volume. 

Permanent Yellow G 872 Peroxypivalic xid, tert-butyl ester 569... 

The tetracyclines are not given to cliildren younger tlian 9 years of age unless tlieir use is absolutely nec sary because tliese dni may cause permanent yellow-gray-brown discoloration of tlie teeth. The use of the tetracyclines, especially prolonged or repeated therapy, may result in bacterial or fungal overgrowth of nonsus-ceptible organisms. 

To obtain rubidium, the filtrate from the first fractional precipitation of silicomolybdates is used to dissolve the first fraction of the RbCl-KCl precipitate obtained during the separation of CsCl by treatment with alcohol. Next, the silicomolybdate reagent is added until the solution acquires a permanent yellow color, and most of the Rb present completely precipitated. The precipitate is washed four times (vigorous stirring with 200-ml. portions of 2.5N HCl, filtered through a fritted glass filter, dried in a vacuum desiccator, decomposed in an HCl stream, and is finally freed of SiOs, as described above. 

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