Aqueous plant products

The types of microorganisms found in various products are Pseudomonas species, including Pseudomonas aeruginosa, Salmonella, species, Staphylococcus aureus, and Escherichia coli. The USP and other pharmacopoeias recommend certain classes of products to be tested for specified microbial contaminants, e.g., natural plant, animal, and some mineral products for the absence of Salmonella species, suspensions for the absence of E. coli, and topically administered products for the absence of P. aeruginosa and S. aureus. Emulsions are especially susceptible to contamination by fungi and yeasts. Consumer use may also result in the introduction of microorganisms. For aqueous-based products, it is therefore mandatory to include a preservative in the formulation in order to provide further assurance that the product retains its pharmaceutically acceptable characteristics until it is used by the patient. 

Other assays have been used to evaluate the antioxidant activity against H202 of several plant-based products, namely, fruit juices from different cultivars of berries (Wang and Jiao 2000), fractions rich in phenolics isolated from the aqueous by-products obtained during the milling of oil palm fruits (Balasundram and others 2005), cherry laurel fruit and its concentrated juice (Liyana-Pathirana and others 2006), and strawberries and blackberries treated with methyl jasmonate, allyl isothiocyanate, essential oil of Melaleuca alternifolia, and ethanol (Chanjirakul and others 2007). 

Benzyl benzoate has been identified in certain natural plant products.1 In the laboratory it has been prepared by the action of (a) benzoyl chloride upon benzyl alcohol,2 (b) benzyl chloride upon sodium benzoate, and (c) alcoholates upon benzaldehyde.3 Recently, Gomberg and Buchler 4 have shown that reaction (b) may be conducted even with aqueous solutions of sodium benzoate. 

The use of aqueous (water-based) plant products, especially the Hydrolats, is becoming more popular with widespread applications. Although many of these have been used for hundreds of years their composition and range of properties is still the subject of research. 

Starch Plant product, so-called carbohydrate, consisting of the elements carbon, hydrogen and oxygen. Raw material for aqueous adhesives (paste, glues). 

Table 2. Antioxidant Activity of Argentine Aqueous Plant Extracts IC50 and 95% Confidence Interval for Inhibition of Hydroperoxide-initiated Chemiluminescence (CL) and the Production of Thiobarbituric Acid-reactive Substances (TBARS) in Rat Liver Homogenates...

From our experience with a range of plant products it would appear that sequential treatments with aqueous SDC, water, PAW, and aqueous... 

Two processes are currently used for the production of propylene oxide. About 50% is produced by the chlorohydrin process and the other 50% by the peroxidation process. The chlorohydrin process is the older technology and it is slowly being replaced by the more economical and environmentally acceptable peroxidation route. There are environmental issues associated with the large aqueous by-product stream of calcium chloride and chlorinated hydrocarbon by-products from the chlorohydrin process. The only producers that will continue to operate chlorohydrin plants are highly integrated caustic-chlorine producers who have chlorine production facilities which can handle the calcium chloride by-product and chlorinated hydrocarbons [9]. 

Although many problems still remain to be overcome to make the process practical (not the least of which is the question of the corrosive nature of aqueous HBr and the minimization of formation of any higher brominated methanes), the selective conversion of methane to methyl alcohol without going through syn-gas has promise. Furthermore, the process could be operated in relatively low-capital-demand-ing plants (in contrast to syn-gas production) and in practically any location, making transportation of natural gas from less accessible locations in the form of convenient liquid methyl alcohol possible. 

The ease with which amines are extracted into aqueous acid combined with their regeneration on treatment with base makes it a simple matter to separate amines from other plant materials and ni trogen containing natural products were among the earliest organic compounds to be studied Their basic... 

Most of the HCl produced is consumed captively, ie, at the site of production, either in integrated operations such as ethylenedichloride—vinyl chloride monomer (EDC/VCM) plants and chlorinated methane plants or in separate HCl consuming operations at the same location. Captive use of anhydrous HCl accounted for 80—85% of the total demand in 1989. The combined merchant market for anhydrous and aqueous HCl in that same year was about 9.1 X 10 metric tons on the basis of 100% HCl (see Table 12) (73). 

Hydrochloric acid [7647-01-0], which is formed as by-product from unreacted chloroacetic acid, is fed into an absorption column. After the addition of acid and alcohol is complete, the mixture is heated at reflux for 6—8 h, whereby the intermediate malonic acid ester monoamide is hydroly2ed to a dialkyl malonate. The pure ester is obtained from the mixture of cmde esters by extraction with ben2ene [71-43-2], toluene [108-88-3], or xylene [1330-20-7]. The organic phase is washed with dilute sodium hydroxide [1310-73-2] to remove small amounts of the monoester. The diester is then separated from solvent by distillation at atmospheric pressure, and the malonic ester obtained by redistillation under vacuum as a colorless Hquid with a minimum assay of 99%. The aqueous phase contains considerable amounts of mineral acid and salts and must be treated before being fed to the waste treatment plant. The process is suitable for both the dimethyl and diethyl esters. The yield based on sodium chloroacetate is 75—85%. Various low molecular mass hydrocarbons, some of them partially chlorinated, are formed as by-products. Although a relatively simple plant is sufficient for the reaction itself, a si2eable investment is required for treatment of the wastewater and exhaust gas. 

Chevron Chemical Co. began commercial production of isophthahc acid in 1956. The sulfur-based oxidation of / -xylene in aqueous ammonia at about 320°C and 7,000—14,000 kPa produced the amide. This amide was then hydrolyzed with sulfuric acid to produce isophthahc acid at about 98% purity. Arco Chemical Co. began production in 1970 using air oxidation in acetic acid catalyzed by a cobalt salt and promoted by acetaldehyde at 100—150°C and 1400—2800 kPa (14—28 atm). The cmde isophthahc acid was dissolved and recrystallized to yield a product exceeding 99% purity. The Arco technology was not competitive and the plant was shut down in 1974. 

Sasol Fischer-Tropsch Process. 1-Propanol is one of the products from Sasol s Fischer-Tropsch process (7). Coal (qv) is gasified ia Lurgi reactors to produce synthesis gas (H2/CO). After separation from gas Hquids and purification, the synthesis gas is fed iato the Sasol Synthol plant where it is entrained with a powdered iron-based catalyst within the fluid-bed reactors. The exothermic Fischer-Tropsch reaction produces a mixture of hydrocarbons (qv) and oxygenates. The condensation products from the process consist of hydrocarbon Hquids and an aqueous stream that contains a mixture of ketones (qv) and alcohols. The ketones and alcohols are recovered and most of the alcohols are used for the blending of high octane gasoline. Some of the alcohol streams are further purified by distillation to yield pure 1-propanol and ethanol ia a multiunit plant, which has a total capacity of 25,000-30,000 t/yr (see Coal conversion processes, gasification). 

Industrial production of sodium nitrite is by absorption of nitrogen oxides (NO ) into aqueous sodium carbonate or sodium hydroxide. NO gases originate from catalytic air oxidation of anhydrous ammonia, a practice common to nitric acid plants ... 

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