Acid hydrolysis homogeneous

Figure 4. TLC behavior (0.25 mm, Silica gel GF-254 hexane-ethyl acetate, 9 1) of organic extracts of t4C-cis-chlordane treated cichlids (A) and exposure water (C). Fractions B and D show the compounds released by acid hydrolysis of aqueous phase of fish homogenate and exposure water, respectively.

The extraction and measurement of lipids may require several steps, these include (1) Pretreatment, including drying, size reduction, and possibly acid hydrolysis to release lipids. (2) Homogenization of the tissue in the presence of a sol vent/solvent system. (3) Separation of liquids from solids. (4) Removal of nonlipid contaminants. (5) Removal of solvent and drying. (6) Calculating the content of lipids by weight difference. 

The overall rate law of homogeneous acid hydrolysis of glycosides is given by... 

A tartrate-modified solid Ti catalyst has also been prepared starting from a montmorillonite clay (31). This clay can be pillared with Ti polycations prepared by acid hydrolysis of Ti(OiPr)4. In the presence of tartrate ester, an allylic alcohol such as tram-2-buten-l-ol is epoxidized in 91% yield with 95% ee. These results are superior even to those for the homogeneous catalyst. Moreover, the reaction also proceeds in the absence of the molecular... 

The most numerous cases of homogeneous catalysis are by certain ions or metal coordination compounds in aqueous solution and in biochemistry, where enzymes function catalytically. Many ionic effects are known. The hydronium ion H3O and the hydroxyl ion OH catalyze hydrolyses such as those of esters ferrous ion catalyzes the decomposition of hydrogen peroxide decomposition of nitramide is catalyzed by acetate ion. Other instances are inversion of sucrose by HCl, halogenation of acetone by H and OH , hydration of isobutene by acids, hydrolysis of esters by acids, and others. 

Hao, Z., Iqbal, A. and Herren, F. (1999c). l,4-Diketo-3,6-bis-4-chloro-phenyl-pyrrolopyrrole in /3 and y modification, prepd. by acid hydrolysis of soluble carbamate. Derivation and preparation by cooling. Ciba-Geigy Ltd. EP 690059 B1. [271 ] Harano, Y. and Oota, K. (1978). Measurement of crystallization of potassium bro-mate from its quiescent aqueous solution by differential scanning calorimeter. Homogeneous nucleation rate. /. Chem. Eng. J., 11, 159-61. [70]... 

Little work has been published concerning the isolation of oligosaccharides following graded, acidic hydrolysis of heparin. Wolfrom and co-workers have studied the partial, acid hydrolysis of a carefully purified heparin. (Purification was effected through the benzidine salt and the neutral barium salt was fractionally precipitated from water. The less-soluble fraction, after conversion to the barium acid salt, had a N S ratio of 2 5 and 5 sulfate groups per tetrasaccharide period, consumed 1 mole of periodate per tetrasaccharide period, and was shown to be homogeneous by electrophoresis and by countercurrent distribution. The molecular... 

Unger and coworkers [26] described the synthesis of FPS containing l,2-epoxy-3- pro-poxypropyl groups. Initially, polyethoxysiloxane (MW = 800) was prepared from TEOS by acid hydrolysis, which was further used in hydrolytic polycondensation with 1,2-epoxy-3-propoxypropyltriethoxysilane. Homogeneity of the reaction medium in the second stage was maintained by addition of sodium or ammonium hydroxide, so that the final product contained either 1,2-dihydroxyl-3-propoxypropyl or hydroxylamine functional groups. 

Indole-3-acetic acid (Fig. 4.16) may be extracted from plant tissue after first homogenizing a 0.1-g sample and extracting the plant tissue with 75mAf potassium phosphate dibasic. After extraction, the pH is adjusted to 2.7 with 2.8 M phosphoric acid and the sample is dialyzed with 15 mL 0.1M potassium phosphate dibasic. The pH adjustment is necessary to protonate the acetic acid functionality for good retention on the C-18 sorbent. Use a trifunctional sorbent that is resistant to acid hydrolysis. 

When endogenous insulin-like material was destroyed by acid-hydrolysis after homogenization of the cells no insulin was... 

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