Calcium hydroxide extracts

Cascara sagrada is used as a cathartic. It is most useful when prepared as a fluid extract, and tends to be a mild laxative causing Htfle discomfort. However, on prolonged use it may result in characteristic melanotic pigmentation of the rectal mucosa. The bitter taste can be lessened, owing to neutralization of the acid constituents, if the ground substance is moistened and mixed with magnesium or calcium hydroxide. This treatment may lessen the potency of the preparation. 

Magnesium sulfate heptahydrate may be prepared by neutralization of sulfuric acid with magnesium carbonate or oxide, or it can be obtained directly from natural sources. It occurs abundantly as a double salt and can also be obtained from the magnesium salts that occur in brines used for the extraction of bromine (qv). The brine is treated with calcium hydroxide to precipitate magnesium hydroxide. Sulfur dioxide and air are passed through the suspension to yield magnesium sulfate (see Chemicals frombrine). Magnesium sulfate is a saline cathartic. 

Preparation of w-Phenyl-tert-Butylamine 24 grams of the urea derivative obtained as indicated above, were well mixed with 96 grams of calcium hydroxide in a flask immersed in an air bath and provided with a dropping funnel the stem of which reached the bottom of the flask. The mixture was heated to 240°-260°C (inside temperature) for 7 hours during which time 86 cc of water was slowly added. The vapors were collected in a receiver cooled with ice. After extraction with ether and distillation, the product was obtained as a colorless liquid boiling from 80°-84 C at 9 mm according to U.S. Patent 2,590,079. 

Calcium carbonate is a common inorganic compound known as limestone. Calcium carbonate has many applications in industries such as medicine, agriculture, paint plastic and surface coatings etc. The vast majority of calcium carbonate used in industry is extracted by mining process. Pure calcium carbonate (e.g. for food or pharmaceutical use), is synthesized by passing carbon dioxide into a solution of calcium hydroxide slurry. In this process calcium carbonate precipitates out, and this grade of product is referred to as precipitate calcium carbonate (abbreviated as PCC). The common reaction is as follows ... 

Cotterill [222] has developed a procedure, discussed below, in which the herbicides are extracted from soil with saturated calcium hydroxide solution. After clean-up the residues are ethylated using iodoethane and tetrabutylammonium hydrogen sulphate as counter ion. Liquid-liquid partition and the use of a macroreticular resin column were compared as clean-up steps and the reaction conditions for optimum yield of ethyl ester were evaluated. 

Many methods have been reported for the extraction of these compounds from soil. Khan [225] used acidified acetone followed by methylation with diazomethane for the simultaneous determination of 2,4-D, Dicamba and Mecoprop residues, as did Bache and Lisk [226] for Ioxynil. Abbott et al. [227] developed a method for MCPA, MCPB, 2,4-D Dichloroprop and 2,4,5-T in which dilute sulphuric acid and diethyl ether were used for extraction. Byast et al. [101] have shown that diethyl ether-chloroform-acetic acid is a suitable extractant for 2,4,5-T, 2,4-D, Dichloroprop and Dicamba [101] and saturated calcium hydroxide solution is efficient for Picloram [228] and 3,6-dichloropicolinic acid [229]. 

Since parasorbic acid was previously isolated by steam distillation of the juice of mountain ash berries (.S), we steam distilled a sample of the cranberry leaf extract, but obtained little 2. The literature reports that before the ash berry juice was distilled, it was treated with calcium hydroxide to precipitate malic acid. Tschesche later showed that such treatment followed by acidification converted the glucoside of parasorbic acid, into the free acid (lactone), 2, (9). This base treatment effects a B-ellmination of the glucose fragment. In the absence of this base treatment, no free parasorbic acid was liberated from the berries. 

When the cranberry leaf extract was treated with calcium hydroxide followed by acidification and extraction with ether, parasorbic acid was indeed isolated. It was identified from the IR and HMR spectra of the crude extract and by identical retention time on two glc columns with an authentic sample of parasorbic acid. We then analyzed samples of the cranberry leaf extract by glc before and after treatment with calcium hydroxide (followed by acidification), samples of parasorbic acid alone, and extract plus parasorbic acid (in the presence of calcium hydroxide followed by acidification). Our results (Table I) show that parasorbic acid from the extract was obtained only upon calcium hydroxide treatment. This result agrees with Tschesche s observations on mountain ash berries. 

Having the glucoside, we could now determine its concentration in the leaves. Extract samples of varying sizes were subjected to calcium hydroxide treatment, acidification, extraction, and glc quantitation. The amounts of parasorbic acid obtained from the samples are shown in Figure 1 to be proportional to sample size. 

Pipette 5 ml of each soil extract into a silica evaporating basin, add 0.25 g sucrose and 2 ml of satd calcium hydroxide solution, and proceed as above as far as measuring the absorbance at 420 nm. 

However carefully prepared, bleaching powder always contains an excess of lime at any rate, a deposit of slaked lime is always found as a residue when bleaching powder is extracted with water. Since the available chlorine in commercial bleaching powder usually ranges between 36 and 38 per cent., and under the very best conditions a maximum of about 43 5 per cent, of available chlorine is taken up, it is inferred that the calcium hydroxide, Ca(0H)2, is not completely sat. with chlorine, and that calcium hydroxide is present—either free or combined. 

The pulp recovered during screening may be transferred to a pulp-wash operation to yield further soluble solids by counter-current extraction with water. The washed pulp may be held for further processing or included with the bulk of ejected peel material from the extractors. This is milled, treated with lime (calcium hydroxide or calcium oxide) to break down pectin and reduce water retention, pressed, dried to c.10-12% moisture content and finally converted to pellets. Being high in carbohydrates these are used as filler in livestock feed blends. 

The extraction of calcium took place inside a water-filled, stirred reactor for 15 min, which resulted in a calcium hydroxide concentration of 1.1 gT1 for paper bottom ash and 0.46gT1 for steel slag. The formed hydroxide slurry was separated from the solids and carbonated by injecting it with C02 at a rate of 25 ml min-1. However, the feasibility of the process should be investigated with a cost and environmental assessment before any firm conclusions can be drawn, as was also the case for a process described by Gorset et al. [59]. 

Certain free bases of alkaloids were found to be quite soluble in pure supercritical C02 even under mild supercritical conditions. However, the alkaloids were not extracted as much as expected from their solubilities [37]. This discrepancy was assumed to be due to the fact that most alkaloids exist in the form of salts in the plant. Alkaloids have been extracted from plant materials traditionally by extraction processes with the addition of ammonia or calcium hydroxide. Accordingly, the use of basified modifiers in SFE, rather than simple polar modifiers was investigated, in the hope that the extraction efficiencies of alkaloids from their plant of origin would be enhanced. 

Various workers [28,34,41] have used different extraction solutions in the ion-selective electrode method, depending on the soil being analysed. The most important are [28,32,35-37] potassium sulfate [39], aluminium sulfate [30], copper (II) sulfate [32], calcium hydroxide [33], and copper sulfate(II) with aluminium and silver resins [41 ]. 

Lopez Garcia et al. [2] have described a rapid and sensitive spectrophotometric method for the determination of boron complex anions in plant extracts and waters which is based on the formation of a blue complex at pH 1 - 2 between the anionic complex of boric acid with 2,6-dihydroxybenzoic acid and crystal violet. The colour is stabilised with polyvinyl alcohol. At 600 nm the calibration graph is linear in the range 0.3-4.5 xg boron per 25 ml of final solution, with a relative standard deviation of 2.6% for xg/l of boron. In this procedure to determine borate in plant tissues, the dried tissue is treated with calcium hydroxide, then ashed at 400 °C. The ash is digested with 1N sulfuric acid and heated to 80 °C, neutralized with cadmium hydroxide and then treated with acidic 2,6-dihydroxybenzoic acid and crystal violet, and the colour evaluated spectrophotometrically at 600 nm. Most of the ions present in natural waters or plant extracts do not interfere in the determination of boron complex anions by this procedure. Recoveries of boron from water samples and plant extracts were in the range of 97 -102%. 

Extract from Nicotiana tabacum Calcium hydroxide Calcium sulfate... 

Filter the extracted reaction mixture (after the extraction process), to filter-off the calcium hydroxide... 

Free calcium hydroxide was determined by a modified Franke extraction procedure (24), most of the data having been obtained by the time-variation method (TVM). The unhydrated material was determined by x-ray quantitative analysis, using magnesium hydroxide as an internal standard, as described previously (21). The calibration equations for all three calcium silicates were of the form... 

In order to extract the morphine, the opium resin must first be prepared. This is achieved by adding the raw opium to boiling water, in which the alkaloids dissolve, while the insoluble material can be removed while it floats, or is filtered from the solution. To extract the morphine from the processed opium, the latter is placed in a large volume of boiling water and calcium hydroxide added. The water is cooled and the unwanted alkaloids precipitate, while the morphine and some codeine remain in solution. The solution is then re-heated and ammonium chloride (and sometimes ethanol and diethyl ether) added. When the pH reaches 8-9, the... 

In the alkali process, demineralized bones (ossein) or cattle skins are usually used. The animal tissue is held in a calcium hydroxide (lime) slurry for a period of 1-3 months at 15-20°C. At the end of the liming, the stock is washed with cold water to remove as much of the lime as possible. The stock solution is then neutralized with acid (HGl, H2SO4, H3PO4) and the gelatin is extracted with water in an identical manner to that in the acid process. 

Insoluble laminarin (50 g.) is treated with an oxygen-free suspension of calcium hydroxide (60 g.) in 1 liter of water. After 8 days at room temperature, the suspension is filtered, and calcium is precipitated by the addition of the equivalent amount of oxalic acid. Concentration of the filtrate to a volume of 500 ml. causes precipitation of polysaccharide (21.4 g.). After filtration, and concentration to a sirup, extraction with ethanol (3 X 100 ml.) leaves further polysaccharide (7.7 g.). Evaporation of the ethanol extract affords a mixture of the sirupy D-glucometasaocharinic lactones (13.8 g.). After their conversion to the calcium salts, and crystallization from water (finally with the gradual addition of ethanol), there is obtained calcium /3 -D-glucometasao-oharinate (5.8 g.), calcium a -D-glucometasaccharinate (0.6 g.), and a residue of the mixed salts (3.7 g., principally a epimer). 

Natural anhydrite is extracted by open cast or underground mining. A hardenable product is obtained by fine grinding to < 0.2 mm particles and the addition of activators (ca. 2% heavy metal or alkali sulfates, or calcium hydroxide) to natural anhydrite. 

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