Mixing performance Extraction

Mixing performance, 306 Blending, 324 Emulsions, 324 Extraction, 324 Gas-liquid contacting, 324 Gas-liquid dispersion, 325 Liquid-liquid dispersion, 325, 326 Mixing vortex, 311 Motionless mixing, see static mixing National Fire Protection Association, 399 Net positive suction head, 160-194 Available from system, 160, 188, 189,... 

Pressurized fluid extraction is another technology that applies high pressure extraction solution in the sample matrix to perform extraction. The solution is water or water mixed with different polar solvents, and its extraction pressure is lower than 1 atm. The extraction solvent and sample can be heated to 200 °C to weaken the sample matrix and allow solvent to penetrate. Compared to traditional extraction methods, pressurized fluid extraction has short extraction time and requires less solvent. As with other extraction methods, extraction temperature and pressure and solvent composition are very critical to the phenolic acid extraction yield (Palma et al., 2001, 2002 Mukhopadhyay et ah, 2006). 

Recently, other mixed phases for SPME have been considered, like CAR-PDMS (Sanchez-Palomo et al., 2005) and CAR-PDMS-DVB (Sanchez-Palomo et al., 2005 Fedrizzi and Versini, unpublished data) (Figure 5.4). Calibration data calculated by performing extraction of an ethanol 12% (v/v) synthetic wine solution containing several compounds representing different functional groups, and methyl heptanoate as... 

In continuous flow methods, the sample is inserted into a flowing stream, where a number of operations can be performed before it is transported to a flow-through detector. Hence, these systems behave as automated analyzers in that they can perform not only sample processing operations but also the final measurement step. Such sample processing operations as reagent addition, dilution, incubation, mixing, dialysis, extraction, and many others can be implemented between the point of sample introduction and detection. There are two different types of continuous flow systems segmented flow analyzers and flow injection analyzers. 

Even so, watch for leaks Sometimes you re asked to perform an extraction in one of these vials, and you decide to shake the bejesus out of the vial to get the two layers to mix. (See Extraction and Washing Microscale.) After you clean your Angers, you will be more gentle when you repeat the experiment, won t you ... 

An emulsion is a colloidal suspension of one liquid in another. Minute droplets of an organic solvent are often held in suspension in an aqueous solution when the two are mixed or shaken vigorously these droplets form an emulsion. This is especially true if any gummy or viscous material was present in the solution. Emulsions are often encountered in performing extractions. Emulsions may require a long time to separate into two layers and are a nuisance to the organic chemist. 

Spray Towers These are simple gravity extractors, consisting of empty towers with provisions for introducing and removing liquids at the ends (see Fig. 15-32). The interface can be run above the top distributor, below the bottom distributor, or in the middle, depending on where the best performance is achieved. Because of severe axial back mixing, it is difficult to achieve the equivalent of more than one or two theoretical stages or transfer units on one side of the interface. For this reason they have only rarely been applied in extraction applications. 

The luciferin-luciferase reaction of Arachnocampa was first demonstrated by Wood (1993), by mixing a cold-water extract and a cooled hot-water extract. The cold-water extract was prepared with 27 mM Tricine, pH 7.4, containing 7mM MgSC>4, 0.2 mM EDTA, 10% glycerol and 1% Triton X-100, and incubated with 1 mM ATP on ice for 18 hr. The hot-water extract was prepared by heating the cold water extract before the addition of ATP at 98°C for 5 min. The luminescence reaction was performed in the presence of 1 mM ATP. 

Miyauchi and Vermeulen (M7, M8) have presented a mathematical analysis of the effect upon equipment performance of axial mixing in two-phase continuous flow operations, such as absorption and extraction. Their solutions are based, in one case, upon a simplified diffusion model that assumes a mean axial dispersion coefficient and a mean flow velocity for... 

The specimen was prepared by the following method. After mixing HAF carbon black (50 phr) with natural rubber (NR) in a laboratory mixer, carbon gel was extracted from unvulcanized mixture as an insoluble material for toluene for 48 h at room temperamre and dried in a vacuum oven for 24 h at 70°C. We made the specimen as a thin sheet of the carbon gel (including carbon black) by pressing the extracted carbon gel at 90°C. The cured specimen was given by adding sulfur (1.5 phr) to the unvulcanized mixture and vulcanized for 30 min at 145°C. The dynamic viscoelastic measurement was performed with Rheometer under the condition of 0.1% strain and 15 Hz over temperatures. 

The number of samples to be processed for every batch produced six samples of 13 tablets each are taken at prescribed times after starting the tablet press (10 tablets are ground and well mixed (= compound sample), two average aliquots are taken, and each is extracted) the additional three tablets are used for content uniformity testing this gives a total of 6 (2 -t- 3) = 30 determinations that have to be performed. 

Marigold petals are rich sources of xanthophyUs, mainly lutein esters. To increase the coloring power, chemical extraction of the colorant from flower meal is performed or a new enzymatic procedure is applied. It was shown that treatment with cellulases or mixed saprophyte microorganisms or solid state fermentation improved the xanthophyll extraction yield. ... 

Co (I I) complex formation is the essential part of copper wet analysis. The latter involves several chemical unit operations. In a concrete example, eight such operations were combined - two-phase formation, mixing, chelating reaction, solvent extraction, phase separation, three-phase formation, decomposition of co-existing metal chelates and removal of these chelates and reagents [28]. Accordingly, Co (I I) complex formation serves as a test reaction to perform multiple unit operations on one chip, i.e. as a chemical investigation to validate the Lab-on-a-Chip concept. 

The effectiveness of a number of crude oil dispersants, measured using a variety of evaluation procedures, indicates that temperature effects result from changing viscosity, dispersants are most effective at a salinity of approximately 40 ppt (parts per thousand), and concentration of dispersant is critical to effectiveness. The mixing time has little effect on performance, and a calibration procedure for laboratory dispersant effectiveness must include contact with water in a manner analogous to the extraction procedure otherwise, effectiveness may be inflated [587]. Compensation for the coloration produced by the dispersant alone is important only for some dispersants. 

A water sample (500-mL) is acidified to pH 3 with HCl and mixed with 20 mL of saturated NaCl solution. The sample is extracted via liquid/liquid partitioning into methylene chloride (3 x 50 mL). The combined methylene chloride fraction is reduced to dryness via rotary evaporation and the residue reconstituted in water-ACN (3 1, v/v). The final determination is performed using HPLC/UV with a two-column switching system. 

Enzyme-linked immunosorbent assay (ELISA). Li and Li developed an ELISA procedure for imidacloprid to determine its residues in coffee cherry and bean extracts. A 25-g amount of sample extracted with 300 mL of methanol and 1% sulfuric acid (3 1, v/v) for 3 min. An aliquot of the sample extract (0.5 mL) is mixed with 1 mL of water and a gentle stream of nitrogen is used to evaporate methanol. The solution is then extracted with 1 mL of ethyl acetate, the extract is reconstituted in 1 mL of PBST (phosphate-buffered saline containing 0.05% Tween 20) and competitive ELISA is performed to quantify imidacloprid in the extract. Eor methanol extracts of coffee cherries and beans fortified with imidacloprid at 0.5 mgL recoveries of imidacloprid by the ELISA method were 108 and 94, respectively. 

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