Whatman

Whatman No. i filter-paper, and handled as little and as cleanly as possible. 

Method. Prepare a paper strip from Whatman No i filter paper, as in the previous experiment, and draw a light pencil line about 3 cm. from the bottom cf. Fig. 25(B)). Mark three points A, B and C symmetrically on this line, if possible 2 cm. apart. Using the fine pipette, or a capillary tube, apply sufficient of solution (A) to the point A to give a damp spot about 0-5 cm. in diameter. Using a thoroughly washed pipette or a fresh capillary tube on each occasion, apply solution (B) and (C) to the points B and C respectively. Dry the strip in the air. 

The addition of a Whatman filter tablet or of a little diatomaceous earth (Super Cel. etc.) assists in the filtration of the finely divided manganese dioxide. 

Wetting energies Wet-web strength Whale Oil Whatman 3 MM Whatman No. 1 Wheat... 

Paper Electrophoresis. Paper (qv) as an electrophoretic matrix was employed in some of the first electrophoretic techniques developed to separate compounds. Paper is easier than a gel matrix because the paper matrix requires no preparation. Besides being easy to obtain, paper is a good medium because it does not contain many of the charges that interfere with the separation of different compounds. Two types of paper employed in this type of electrophoresis are Whatman 3 MM (0.3 mm) and Whatman No. 1 (0.17 mm). 

Acrylamide [79-06-1 ] M 71.1, m 84°, b 125°/25mm. Crystd from acetone, chloroform, ethyl acetate, methanol or benzene/chloroform mixture, then vac dried and kept in the dark under vac. Recryst from CHCI3 (200g dissolved in IL heated to boiling and filtered without suction in a warmed funnel through Whatman 541 filter paper. Allowed to cool to room temp and kept at -15° overnight). Crystals were collected with suction in a cooled funnel and washed with 3(X)mL of cold MeOH. Crystals were air-dried in a warm oven. [Dawson et al. Data for Biochemical Research, Oxford Press 1986 p. 449.]... 

RS- P-Aminoisobutyric acid (a-methyl-P-alanine) [10569-72-9] M 103.1, m 176-178 , 178-180 , 181-182 , R -(-)- isomer [144-90-1] m 183 , [a] -21 (c 0.43, HjO), pKes,(,) 3.7, pKEst(2) 10.2. Colorless prisms from hot H O, were powdered and dried in vacuo. The purity is checked by paper chromatography (Whatman 1) using ninhydrin spray to visualise the amino acid Rp values in 95% MeOH and n-PrOH/5N HCOOH (8 2) are 0.36 and 0.50 respectively. [Kupiecki and Coon Biochem Prep 7 20 7960 Pollack J Am Chem Soc 65 1335 7943.] The R-enantiomer, isolated from iris bulbs or human urine was crystd from H2O and sublimed in vacuo [Asen et al. J Biol Chem 234 343 7959]. The RS-hydrochloride was recrystd from EtOH/Et20 m 128-129 , 130° [Bbhme et al. Chem Ber92 1258, 1260, 1261 7959]. 

Cytochrome from Rhodospirillum rubrum. ( 2itJ 5S 0.967). Purified by chromatography on a column of CM-Whatman cellulose [Paleus and Tuppy Acta Chem Scand 13 641 7959]. 

Geranyl pyrophosphate [763-10-0 (NH4 salt)] M 314.2, pKeski)-<2, pKesi(2) <2, pKesK3)-3.95, PKesi(4) 6.26. Purified by paper chromatography on Whatman No 3 MM paper in a system of isopropyl aleohol/isobulyl aleohol/ammonia/waler (40 20 1 39), Rp 0.77-0.82. Stored in the dark as the ammonium salt at 0°. 

Mevalonic acid 5-phosphate [1189-94-2] M 228.1, pKes,(d 1.5 (PO4H2), pKEst(2) 4.4 (CO2H), pKEst(3) (P04H ). Purified by conversion to the tricyclohexylammonium salt (m 154-156°) by treatment with cyclohexylamine. Crystd from water/acetone at -15°. Alternatively, the phosphate was chromatographed by ion-exchange or paper (Whatman No 1) in a system isobutyric acid/ammonia/water (66 3 30 Rp 0.42). Stored as the cyclohexylammonium salt. 

Pituitary Growth Factor (from human pituitary giand) [336096-71-0]. Purified by heparin and copper affinity chromatography, followed by chromatography on carboxymethyl cellulose (Whatman 52). [Rowe et al. Biochemistry 25 6421 1986.]... 

Since the mixture filters rather slowly, even after storage overnight, a Buchner funnel of at least 20 cm. diameter should be used, and a hard grade of filter paper (such as Whatman no. 50) is recommended. Use of a rubber dam helps to express solvent and exclude moisture from the hygroscopic product. 

Note Under these conditions gentamycins C2 and C2, form a common zone. A separation can be achieved, for example, with methanol — 0.1 mol/1 LiCl in 32% aqueous ammonia solution (5 + 25) on KC18F plates (Whatman) [9]. 

Fig. 3-2. Semipreparative RP-HPLC profile of eyelo(Arg-Lys-X-Pro-X-Ala). The erude sublibrary (160 mol) was dissolved in 0.1 % (v/v) TFA and applied to a Whatman Partisil 10 pm ODS-2 (1 x 50 em) eolumn. The peaks were eluted using a 40-min linear gradient of 0-25 % aeetonitrile in water at a flowrate of 7 mL min . Fractions were collected every 2 min and pooled in three fractions as indicated by arrows 130 pmol of peptides was reeovered (yield 81 %). (Reprinted with permission from ref. [75]. Copyright 1998, Ameriean Chemieal Soeiety.)...

API Filtration. A filter press is used to determine the wall building characteristics of mud. The press consists of a cylindrical mud chamber made of materials resistant to strongly alkaline solutions. A filler paper is placed on the bottom of the chamber just above a suitable support. The filtration area is 7.1 ( 0.1) in.-. Below the support is a drain tube for discharging the filtrate into a graduate cylinder. The entire assembly is supported by a stand so that a 100-psi pressure can be applied to the mud sample in the chamber. At the end of the 30-min filtration time volume of filtrate is reported as API filtration in milliliters. To obtain correlative results, one thickness of the proper 9-cm filter paper, Whatman No. 50, S S No. 5765, or the equivalent, must be used. 

The instruments for the HT-HP filtration test consist essentially of a controlled pressure source, a cell designed to withstand a working pressure of at least 1000 psi, a system for heating the cell, and a suitable frame to hold the cell and the heating system. For filtration tests at temperatures above 200°F, a pressurized collection cell is attached to the delivery tube. The filter cell is equipped with a thermometer well, oil-resistant gaskets, and a support for the filter paper (Whatman No. 50 or the equivalent). A valve on the filtrate delivery tube controls flow from the cell. A nonhazardous gas such as nitrogen or carbon dioxide should be used for the pressure source. 

Procedure. Prepare the sodium tetraphenylborate solution by dissolving 6.0 g of the solid in about 200 mL of distilled water in a glass-stoppered bottle. Add about 1 g of moist aluminium hydroxide gel, and shake well at five-minute intervals for about 20 minutes. Filter through a Whatman No. 40 filter paper, pouring the first runnings back through the filter if necessary, to ensure a clear filtrate. Add 15 mL of 0.1M sodium hydroxide to the solution to give a pH of about 9, then make up to 1 L and store the solution in a polythene bottle. 

Pipette 25.0 mL of the potassium ion solution (about 10 mg K + ) into a 50 mL graduated flask, add 0.5 mL 1M nitric acid and mix. Introduce 20.0 mL of the sodium tetraphenylborate solution, dilute to the mark, mix, then pour the mixture into a 150mL flask provided with a ground stopper. Shake the stoppered flask for 5 minutes on a mechanical shaker to coagulate the precipitate, then filter most of the solution through a dry Whatman No. 40 filter paper into a dry beaker. Transfer 25.0 mL of the filtrate into a 250 mL conical flask and add 75 mL of water, 1.0 mL of iron(III) nitrate solution, and 1.0 mL of sodium thiocyanate solution. Titrate with the mercury(II) nitrate solution as described above. 

Weighing as calcium oxide. Decant the clear supernatant liquid through a Whatman No. 40 or 540 filter paper, transfer the precipitate to the filter, and wash with a cold 0.1-0.2 per cent ammonium oxalate solution until free from chloride. Transfer the moist precipitate to a previously ignited and weighed... 

Procedure. The solution should not exceed 50 mL in volume, all metallic elements should be present as nitrates, and the cerium content should not exceed 0.10g. Treat the solution with half its volume of concentrated nitric acid, and add 0.5 g potassium bromate (to oxidise the cerium). When the latter has dissolved, add ten to fifteen times the theoretical quantity of potassium iodate in nitric acid solution (see Note) slowly and with constant stirring, and allow the precipitated cerium(IV) iodate to settle. When cold, filter the precipitate through a fine filter paper (e.g. Whatman No. 42 or 542), allow to drain, rinse once, and then wash back into the beaker in which precipitation took place by means of a solution containing 0.8 g potassium iodate and 5 mL concentrated nitric acid in 100 mL. Mix thoroughly, collect the precipitate on the same paper, drain, wash back into the beaker with hot water, boil, and treat at once with concentrated nitric acid dropwise until the precipitate just dissolves (20-25 mL... 

Precipitate about 0.1 g potassium (present as potassium chloride in 50 mL water) with 40 mL of the sodium TPB solution added slowly and with constant stirring. Allow to stand for 30 minutes, filter through a sintered-glass filtering crucible, wash with distilled water, and dry for 1 hour at 120 °C. Shake 20-25 mg of the dry precipitate with 200 mL distilled water in a stoppered bottle at 5-minute intervals during 1 hour. Filter through a Whatman No. 40 filter paper, and use the filtrate as the wash liquid. 

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