Precipitants inorganic

The thus yielded active fraction, about 200 ml, was neutralized with sodium hydroxide, concentrated to about 15 ml in vacuo, separating the precipitated inorganic salts therefrom. After decolorization with active carbon, 150 ml of methanol was added, the mixture was allowed to stand overnight at 5°C and the precipitate was collected by filtration. The precipitate was washed with methanol and dried in vacuo to yield crude tuberactinomycin-N hydrochloride (yield, 3.07 g purity, 71 S% recovery, 62%). 

Workup (b) To the mixture arc added 5.6 g (22 mmol) of barium acetate. After chilling for 1 h, the precipitated inorganic phosphate is removed by centrifugation. The supernatant is adjusted to pH 7.5 and diluted with ethanol (1 L). After standing at O C overnight, the precipitated barium salt of the product is collected by centrifugation, washed with ethanol and diethyl ether, then dried under high vacuum yield 7.3 g (92%). 

The temperature of the liquid is now raised, first quickly to 70° and then slowly to 85° this causes precipitation of the dye. After a quarter of an hour the mixture is cooled to 50° precipitated inorganic material is dissolved by adding 15 c.c. of concentrated sulphuric acid and, when the mixture has been cooled completely, the crude dye is filtered as dry as possible at the pump. The product is at once dissolved in 200-300 c.c. of boiling water the solution is filtered and left to crystallise over night after 20 g. of concentrated zinc chloride solution (1 1) and 40 g. of finely powdered common salt have been added. The beautiful crystals, which have a red lustre,... 

Various bacteria, such as spherical bacteria, bacillus, and fibrous bacteria, selectively precipitate inorganic crystals around the surface of the bacterium, though the reasons for this are unclear [13]. Although many studies have been performed on the precipitation of inorganic crystals around bacteria in relation to... 

Finally, in the cool-down section, in which the process stream temperatures are reduced below the critical temperature of water for product separation and recovery, precipitated inorganics may redissolve, but gas phase immiscibility will rise. 

Excess potassium iodide can be recovered by filtering the acid layer, after adding sufficient water to dissolve precipitated inorganic phosphates. 

The solution is evaporated to dryness under reduced pressure on a water bath. In order to remove as much hydrochloric acid as possible, the temperature of the bath is raised to 100° toward the end of the distillation. The residue of amino acid hydrochloride and inorganic salts is suspended in 500 cc. of absolute ethyl alcohol. The suspension is boiled on a steam bath for a short time, then cooled to room temperature and filtered on a Buchner funnel. The residue of inorganic salts is washed with 500 cc. of absolute ethyl alcohol. To the combined filtrates is added 400 cc. of ethyl ether (u. s. p. quality) in order to precipitate inorganic material. After several hours the mixture is filtered, and the residue is washed with a 5 2 mixture of absolute ethyl alcohol and ether. The filtrate is transferred to a 5-1. round-bottomed flask, about 200 cc. of water is added, and the liquids are removed by distillation under reduced pressure. The nearly dry residue is dissolved in 2 1. of water, and the solution is treated with an excess of freshly prepared lead hydroxide (Note 5). The suspension is diluted with water to a volume of about 3.5 1. and is then concentrated under reduced pressure, at as low a temperature as possible, to a volume of about 2 1. The suspension is then filtered with suction (Note 6), and the residue of lead salts is washed thoroughly with water. The cloudy filtrate, which still contains some free ammonia, is concentrated by distillation under reduced pressure to a volume of about 300-400 cc. The mixture is filtered, the filtrate is saturated with hydrogen sulfide gas, and the precipitate of lead sulfide is removed by filtration with suction (Note 6). The solution is now concentrated by distillation under reduced pressure on a water bath, and 1 1. of 95 per cent ethyl alcohol is added to the nearly dry residue of the amino acid. The suspension is boiled under a reflux condenser until nearly all the amino acid is dissolved, and the mixture is then allowed to cool to room temperature. The amino acid, which separates in the form of fine needles, is collected on a Buchner funnel and washed with a little 95 per cent ethyl alcohol. A second crop of... 

The 5 0 from the calcite tests of benthic foraminifera preserved in ocean sediments can be used to estimate upper-ocean density because both the 5 0 of calcite (S Ocaicite) and density increase as a result of increasing salinity or decreasing temperature (Lynch-Stieglitz et al., 1999a). The fractionation between calcite precipitated inorganically and the water in which it forms increases by 0.2%c for every 1 °C decrease in temperature (Kim and O Neil, 1997). The relationship between S Ocaidte and salinity is more complex. The S Ocaidte reflects the 5 0 of the water in which the foraminifera grew. The 5 0 of seawater (S Owater) primarily reflects patterns of evaporation and freshwater influx to the surface of the ocean. Because salinity also reflects these same processes, salinity and... 

There are two common stratigraphic occurrences of chert as bedded cherts associated with shales or iron formations and as nodules in carbonate rocks (Blatt et al., 1980). The bedded cherts are predominant in Precambrian time, reaching a maximum extent 2-3 Ga, when they represented as much as 15% of the sedimentary record. The Precambrian bedded cherts contain microspheres of quartz, suggesting that they may have precipitated inorganically. Commonly, bedded cherts are associated with ophiolite sequences, which may have hydrothermal or metasomatic sources of silicate. The co-occurrence of bedded cherts and shales (typically dark in color) suggests that many cherts form in a hemi-pelagic or deep-sea, open-ocean setting, far from sources of coarse clastic material. In... 

Figure 5 A typical soil aggregate. Sand, silt, and clay particles, cemented by organic matter, precipitated inorganic materials, and microorganisms, bind the soil particles together to form an aggregate. Original drawing by Kim Luoma (Fuhrmann, 1999) (reproduced by permission of Prentice Hall from Principles and Applications of Soil...

In this fashion, the organic material in the animal actually determines the ultrastructure of the precipitated inorganic salts by a remarkably simple templating mechartism. These salts must precipitate within the aqueous... 

Humic substances have been concentrated by vacuum distillation. This method is carried out at low temperatures, which avoids decomposition and chemical reactions within the sample (Jolley et al., 1975), and is faster than freeze-drying (Katz et al., 1972). All solutes are concentrated by this method, and coprecipitated organic matter must be further extracted from precipitated inorganic salts (Katz et al., 1972). Vacuum distillation of humic substances to dryness is not recommended because it results in a dense product that is not easily removed from the drying vessel and may be difficult to dissolve. 

Fig. 10.13 Empirical 5 B calibrations of laboratory precipitated inorganic calcite and cultured biogenic carbonates vs. pH.

For the isolation of non-volatile water soluble compounds or biological materials from water, freeze drying is an effective technique. In this technique the water sample is frozen in a vial and the resulting ice sublimed away under vacuum. Organics are then solubilized in an organic solvent to separate them from the precipitated inorganic salts. 

---