Colorless glass

The filtrate was extracted twice with 100 ml of carbon tetrachloride. The carbon tetrachloride phase was discarded. The aqueous phase was adjusted to pH 11 by addition of 6 N aqueous sodium hydroxide and extracted four times with 300 ml portions of chloroform. The combined chloroform extract was washed three times with 100 ml of saturated aqueous sodium chloride solution and the sodium chloride phase was discarded. The chloroform extract was dried over anhydrous magnesium sulfate, filtered and the filtrate evaporated to dryness under vacuum on a 50° to 60°C water bath. The residue was a clear, colorless glass weighing 45 g analyzing about 95% 7(S)-chloro-7-deoxylincomycin. 

Cuvettes used for UV-VIS spectrophotometry must be transparent to all wavelengths of light for which it is used. If visible light is used, the material must ideally be completely clear and colorless, which means that inexpensive materials, such as colorless plastic and ordinary colorless glass, are perfectly suitable. A case of 500 plastic 1-cm-square cuvettes may cost as little as 50. However, ordinary colorless glass and plastic are not transparent to light in the ultraviolet region. For ultraviolet spectrophotometry, the cuvettes must be made of quartz, which is more expensive. A matched set of two cuvettes to be used in a doublebeam spectrophotometer may cost as much as 400. 

A true colorless glass such as an optical glass must be made with very low iron materials since decolorizing agents would reduce the transmission. The main physical decolorizers are manganese, selenium, cobalt and neodymium oxides. Manganese with a little cobalt is effective in complimenting the iron in the ferric state. 

Pipe-clay also burns white in the fire, and, before the oxybydrogen blowpipe it melts to a transparent, almost colorless glass,. L... 

Introduce 100 cc. of water, containing 5 drops of the above iodeosin solution, into a colorless, glass-stoppered flask, and then overlay it with 30 cc. of ether. Then run in by drops, from a burette, centinormal hydrochloric acid solution, vigorously shaking after the addition of each drop, until the aqueous layer just becomes colorless. Now add 5 drops more of the iodeosin solution. After shaking again, the aqueous layer must not acquire a pink color or, should it do so, the color must disappear on the addition of 1 drop of centinormal hydrochloric acid. 

Procedure Unless otherwise directed, add the specified quantity of the substance, finely powdered if in solid form, in small portions to the comparison container, which is made of colorless glass resistant to the action of sulfuric acid and contains the specified volume of 95% Sulfuric Acid. 

Stir the mixture with a glass rod until solution is complete, allow the solution to stand for 15 min, unless otherwise directed, and compare the color of the solution with that of the specified matching fluid in a comparison container that also is of colorless glass and has the same internal and cross-section dimensions, viewing the fluids transversely against a background of white porcelain or white glass. 

For making color comparisons, use color tubes of clear, colorless glass with a smooth, flat, polished bottom (length 154 mm id 19 mm od 22 mm), and marked to indicate liquid columns of 25.4 and 133.35 mm. 

The nearly colorless glass fragment (object 1) has essentially the matrix composition. The slight green tint probably comes from the very small amounts of iron, copper, and manganese oxides present. 

This product, though still pale yellow, is suitable for most synthetic purposes. Colorless glass-like prisms of m.p. 128-130° (cor.) are obtainable on further crystallization from benzene. 

Prednisolone phosphate eye drops are very photosensitive when packaged in clear colorless glass ampoules as well as in uncolored, high-density polyethylene containers. When exposed to UV and VIS radiation, the drug substance is completely decomposed within a few hours. However, packaging the prednisolone phosphate solution in brown glass vials, results in satisfactory UV-VIS photo protection (6) as shown in Figure 2. 

The photodegradation of doxorubicin, daunorubicin, and epirubicin solutions is more rapid in clear glass than in polyethylene or amber glass containers (61). Colored glass is not preferred for injections since it is difficult to detect discoloration and particulate matter in the liquid preparation. However, a colorless glass capable of cutting off detrimental radiations is still to be discovered. 

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