Hydrochloric acid digestion and

Methods for recovering lignin are the alkali process, the sulfite process, ball milling, enzymatic release, hydrochloric acid digestion, and organic solvent extraction. Alkali lignins are produced by the kraft (22) and soda (23) methods for wood pulping. These... 

Hydrochloric acid digestion takes place at elevated temperatures and produces a solution of the mixed chlorides of cesium, aluminum, and other alkah metals separated from the sUiceous residue by filtration. The impure cesium chloride can be purified as cesium chloride double salts such as cesium antimony chloride [14590-08-0] 4CsCl SbCl, cesium iodine chloride [15605 2-2], CS2CI2I, or cesium hexachlorocerate [19153 4-7] Cs2[CeClg] (26). Such salts are recrystaUized and the purified double salts decomposed to cesium chloride by hydrolysis, or precipitated with hydrogen sulfide. Alternatively, solvent extraction of cesium chloride direct from the hydrochloric acid leach Hquor can be used. 

An official method has been published for the determination of magnesium in plant material [27]. A hydrochloric acid digest of the sample is treated with strontium chloride perchloric acid releasing agent and magnesium is determined by AAS using the 285 nm emission line. See Sect. 7.34.1. 

Hydrochloric acid hydrogen and chlorine (HCI) Fertilizers, photographic developing liquid, PVC (a type of plastic). HCI is made in the human stomach and helps you digest food. 

Dry tissue (1—3 g) is digested with 30 ml of nitric acid, sulphuric and perchloric acids (4 4 1). After heating for approximately 1.5h, the cooled solution is transferred to a 100 ml flask, 30 ml hydrochloric acid added and diluted to 100 ml with water. Suitable aliquots, up to 20 ml, of this solution are used for the subsequent arsenic analysis. 

Total hydrolysable phosphate in water samples was determined after preliminary hydrolysis with sulphuric acid solution. To 50 ml samples was added 0.05 ml phenolphthalein indicator and, in cases where a red colour was observed, the color was discharged with drops of 30 % sulphuric acid solution. To each sample, 1 ml of 30 % sulphuric acid solution was added and diluted to 100ml. The samples were boiled for at least 90 minutes on a hot plate and the final digest was reduced to 25 to 50 ml. To each digest, 6 N sodium hydroxide solution was added until a faint pink color was observed. The faint pink colour was then discharged by adding 50% hydrochloric acid solution and the sample then proceeded to determination of the phosphate using vanadate-molybdate method as in the case of total reactive phosphate. Both the standards and blanks for determination of total hydrolysable phosphate were treated in the same manner as the samples. 

The freeze dried or lyophilised samples of excreta can be digested at low temperatures (170-210°C) for 15-20 min with a minimal acid mixture of nitric and perchloric (1 2). Though this procedure can not destroy the organic matter completely, it should be at least as effective as the mineral acid extraction procedures described for excreta samples (Riner et al.. 1974). Maurer (1977) also found better results by extracting the specimens with a mixture of nitric (65%). hydrochloric acid (25%) and water (3 27 20) compared to those obtained by dry ashing. 

Centurione and Kihara (1994) tested the application of F.L. Smidth s burnability equations and methods, including those of Fundal (1979), Theisen (1992), and Miller (1980), in an analysis of 12 samples of raw feed and corresponding clinkers. Cenfurione and Kihara used an hydrochloric acid digestion mefhod fo calculate Cj25 and concluded that coarse quartz (>45 pm) and limestone (>125 pm) should not exceed 2% and 6%, respectively, by weight of sample. 

A method involving hydrolysis of bacterial cellulose by sulfuric acid has been undertaken in order to obtain nanowhiskers. These nanowhiskers can be dispersed in various solutions, however the nanowhiskers appear stiff and rod-like, and have been reported to aggregate to some degree [146]. Bacterial cellulose nanowhiskers have also been pre-pared by hydrochloric acid digestion [147]. 

Fluid secreted by the stomach containing hydrochloric acid, digestive enzymes (for example pepsinogen) and intrinsic factor which is necessary for vitamin B 2 absorption. Gastric juice secretion is stimulated by gastrin and also by the vagus nerve which responds to the stimulus of food. 

Place an intimate mixture of 125 g. of powdered, anhydrous zinc chloride and 26-5 g. of acetophenonephenylhydrazone in a tall 500 ml. beaker in an oil bath at 170°. Stir the mixture vigorously by hand. After 3-4 minutes the mass becomes hquid and evolution of white fumes commences. Remove the beaker from the bath and stir the mixture for 5 minutes. Then stir in 100 g. of clean, white sand in order to prevent solidification to a hard mass. Digest the mixture for 12-16 hours on a water bath with 400 ml. of water and 12 ml. of concentrated hydrochloric acid in order to dissolve the zinc chloride. Filter off the sand and the crude 2-phenylindole, and boil the solids with 300 ml. of rectified spirit. Treat the hot mixture with a little decolourising carbon and filter through a pre-heated Buchner funnel wash the residue with 40 ml. of hot rectified spirit. Cool the combined filtrates to room temperature, filter off the 2-phenylindole and wash it three times with 10 ml. portions of cold alcohol. Dry in a vacuum desiccator over anhydrous calcium chloride. The yield of pure 2-phenylindole, m.p. 188-189°, is 16 g. 

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