H-filter

V is the average velocity and 12 is the diffusion coefficient. If a solute has T onvection Tdiffiision it enough time to act and will remain in the original stream. If  

The optimal condition is not satisfied for the above example. Therefore, we need to change either the length or the average speed of the system. If we change the length to 1 cm and reduce the velocity to 0.1 mm/s, we have 

This satisfies the required condition of H-filter for separating the small-sized solute, that is, ion from the sample solution as the convection time scales lies between diffusion time scale of species-1 and species-2. 

---

A solution of 2-cyclohexylindole (100mmol) in CHjClj containing NajCO, (7.5 g) was treated with a solution of ethyl 3-bromo-2-(hyroxyimino)pro-panoate (7.35 g. 35 mmol) in CH Clj (50 ml). The mixture was stirred under nitrogen for 16 h, filtered through Celite, and concentrated in vacuo. The... 

FIG. 18-114 Section detail of a caiilked-gasketed-recessed filter plate a) cake recess (h) filter cloth (c) drainage surface of plate (d) caulking strip (e) plate joint (f ) sealing gasket. (ElMCO Process Equipment Co.)... 

Method B A solution of (/ )-oxynitrilase (150 pL, sec Method A) is dropped onto 2 g of Avicel cellulose [soaked in 20 mL of 0.01 M acetate buffer (pH 5.4) for 1 2 h, filtered off and pressed]. 20 mL of ethyl acetate (saturated with 0.01 M acetate buffer, pi I 5.4) are added, followed by 5 mmol of aldehyde and 250 pL (6.5 mmol) of hydrocyanic acid. After stirring at r.t. (Tabic 1) the mixture is filtered, and the filter cake pressed and washed with ethyl acetate. The combined solutions are dried and concentrated. 

Weigh 50 g (dry soil base) of the sample into a 500-mL round-bottom flask and add 120 mL of methanol and 40 mL of water. Attach a condenser to the flask and reflux at 75 °C for 1 h. Filter the mixture through a filter paper by suction and collect the filtrate in a 500-mL round-bottom flask. Wash the residue and the flask with 80 mL of methanol and filter and collect the washings in the same manner. Combine the filtrates in a 500-mL separatory funnel. 

Weigh 10 g of the sample into a 500-mL Erlenmeyer flask. Add 120 mL of water-acetone (1 4, v/v) and shake the flask vigorously for 1 h. Filter the extract through a Alter paper in a Buchner funnel into a 1-L round-bottom flask with suction. Rinse the flask and the filter cake twice with 50 mL of acetone. Combine the filtrates and concentrate to 20-30 mL under reduced pressure at 40 °C. 

Weigh 50 g of the ground hulled rice, citrus flesh, or tomato sample (20 g citrus peel or rice straw) into a 500-mL Erlenmeyer flask and extract with 250 mL of acetone (or methanol for rice straw) by shaking for 1 h. Filter by suction and collect the extract in a 500-mL round-bottom flask. Wash the cake with 100 mL of acetone (or methanol for rice straw) and filter off. Combine the filtrates and concentrate to around 2 mL at 40 °C with a rotary evaporator. 

Rate = /cobsd[H + ][RuH]. Conditions 70 mg of the complex and 2 g of Amberlite resin IRA-400(C1) were dissolved in 30 ml H20, stirred for 6 h, filtered, and stored at 5 °C. Reaction mixtures were made by mixing 2.5 cm3 Britten-Robinson buffer (ionic strength 0.12 mol/L, pH between 2 and 3) with 0.5 cm3 of the Ru-hydride solution. 

The haloalkane in MeCN is added to an excess of finely powdered KSCN and l % molar equivalent of Aliquat. The mixture is stirred at room temperature for ca. 2 h, filtered, and the filtrate is fractionally distilled under reduced pressure to produce the thiocyanate (>95%). 

As discussed earlier, with respect to bacterial mutagens, one of the applications of mutagen assays is their use in focusing analytical studies directed to determining the chemical composition. This approach was also used by Hannigan and co-workers (1998), who carried out a bioassay-directed chemical analysis using the hlAlv2 human cell line of a composite sample made up of a portion of every 24-h filter sample. 

The peptide was oxidized to the aldehyde active form 62 using freshly prepared y-Mn02 (50 mg) added to a soln of the above peptide (2 mg) in DMSO (120 pL). The mixture was stirred in the dark for 12 h, filtered through Celite, and the column washed with H20 for maximum recovery. The filtrate was filtered on a 1.2-pm filter and lyophilized to give the pyridoxal peptide 62 as a yellow oil (15 10%),... 

Purification of 18 A suspension of 18 (5.8 g, 20 mmol), anhyd K2C03 (3 g. 20 mmol), and H20 (24 mL) was stirred and refluxed for 1 h. filtered, and cooled to give the potassium salt as broad yellow plates yield 6.1 g (98%) an analytical sample was recrystallized from EtOH. 

---