Elution with water

Purified by paper chromatography using /crt-butanol-water, cutting out the main spot and eluting with water. Also purified by adsorption onto an apo-flavodoxin column, followed by elution and freeze drying Crystd from acidic aqueous soln. [Mayhew and Strating Eur J Biochem 59 539 1976.]... 

Finally,Captopril is produced. Thethioester (0.85g) isdissolved in5.5N methanolicammonia and the solution is kept at room temperature for 2 hours. The solvent is removed in vacuo and the residue Is dissolved in water, applied to an ion exchange column on the H cycle (Dowex 50, analytical grade) and eluted with water. The fractions that give positive thiol reaction are pooled and freeze dried. The residue Is crystallized from ethyl acetate-hexane, yield 0.3 g. The 1 -(3-mercapto-2-D-methylpropanoyl)-L-proline has a melting point of 103°C to 104°C. 

To ensure maximum pigment retention, the acidic eluates should be checked for their pH values and if required, aqueous ammonia has been proven viable for pH adjustment to reach 5 to 7 pH values. While Sephadex G types were used in earlier studies for purification and desalting, Sephadex LH-20 is the material of choice today. Since the betalains will elute with water, it is doubtful whether effective salt removal is possible. However, Sephadex LH-20 has proven excellent for removing... 

Samples dissolved in methanol, diluted in water and injected in Spherisorb ODS-2 colunm, elution with water/acetonitrile (7 3) containing 5 mM octylamineZ-phosphoric acid at pH 6.4 Separation on STR ODS-II colunms and gradient elution with 20 mM anunonium phosphate buffer (pH 6.8)/isopropanol (25 1 v v) and acetonitrile) at 40°C... 

Experiment 2 The load and the column equilibration buffer were 1 M ammonium acetate. The DMT-on product was eluted with water. 

Riley and Taylor [39] have studied the uptake of about 30 organics from seawater onto the resin at pH 2 - 9. At the 2 - 5 p,g/l level none of the carbohydrates, amino acids, proteins or phenols investigated were adsorbed in any detectable amounts. Various carboxylic acids, surfactants, insecticides, dyestuffs, and especially humic acids are adsorbed. The humic acids retained on the XAD-1 resin were fractionated by elution with water at pH 7, M aqueous ammonia, and 0.2 M potassium hydroxide. 

Another ion-exchange system has recently been developed by Nippon Rensui [8]. The Nippon Rensui system employs an amphoteric ion-exchange resin called Diaion DSR01 which can be eluted with water. In the DSR01 system, the resin takes up the sodium chloride and rejects the sodium sulphate. Purified NaCl is then recovered from the resin by water elution. This seems like a difficult approach since it is necessary to take-up huge amounts of NaCl on the resin in order to separate out a relatively small amount of sulphate impurity. Excessive dilution of the purified brine may also be an issue with this process. 

Fig. 2.46. Densitogram of racemic naringenin on MCTA layers eluted with water-methanol (80 20, v/v). The development distance was 15cm the separation time 2 h. 0.5 pi (full line) and 1 pi (dashed line) of ( )-naringenin solution (4 mg/ml). Reprinted with permission from L. Lepri et al. [137].

The target dipeptide product was purified on a SephadexG-10 column (16 mm x 1000 mm) equilibrated and eluted with water at the elution rate of 1.0 mL min . The elution process was monitored at 220 nm. The fractions collected were lyophihzed to afford the desired product (29.6 mg). The HPLC purity and the yield of the product were 93.5 % and 82.9 % respectively. 

The fractions were concentrated and subjected to the ninhydrin assay. Thereafter, fractions eluted with BuOH/HAc/Fl20 were combined and concentrated, as were the fractions eluted with water. The presence of cross-links was verified by TLC. 

Part of the high molecular weight fractions contained ninhydrin-positive compounds displaying Rf 0 on TLC-plates (BUOH/HAC/H2O), characteristic of cross-links. To remove contaminating common amino acids, the selected fractions were further purified by adsorption chromatography on cellulose. Most of the amino acids eluted with BUOH/HAC/H2O, accounting for about three quarters of the total reactivity towards ninhydrin. The amino acids eluted with BUOH/HAC/H2O displayed spots with widely varying mobilities after TLC separation with the same eluent, whereas those eluted with water showed zero and very low mobility. 

The specific radioactivities of uracil were 14C, 0.6 mC/mAf T, 7.75 inC/mAf ratio T/14C = 12.9. The concentration of uracil was 10 3M. Photoproducts were isolated by paper chromatography with n-butanol/water, 86.14. Spots were eluted with water and radioactivity determined in a Tri Carb 314 EX (Packard Instruments). 

Eor obtaining neutral fraction the column was eluted with water firstly. The acidic fractions were obtained by elution of linear NaCI gradient (0-1.4 M) in water. The carbohydrate elution profile was determined using the phenol-sulphiric acid method, finally two column volumes of a 2 M sodium chloride solution in water were eluted to obtain the most acidic polysaccharide fraction. The relevant fractions based on the carbohydrate profile were collected, dialysed and lyophilized. 

Elution of Lignin Sulfonates with Water. As can be seen from Figures 1, 2, 3, and 4, the fractionation of lignin sulfonates on elution with water through Sephadex G-50 and G-75 takes place in such a way that the logarithms of... 

Figure 6 shows that the proteins used for calibration elute in the same way as lignin sulfonates, which justifies the use of proteins as calibration standards. A comparison between Figures 4 and 6 shows that elution with an electrolyte solution fractionates lignin sulfonates in the range 3 000-80 000 dalton, but that elution with water fractionates those in the range 20 000-100 000 dalton. 

One disadvantage of using salt solution as eluent is that the lignin sulfonates tend to adsorb onto the gel matrix, resulting in a resolution inferior to that obtained by elution with water. On the other hand, elution behavior with water is adversely affected by the polyelectrolyte properties of the lignin sulfonates. Adsorption, which is caused by the phenolic hydroxyl... 

Alizarin Red S (sodium salt, H2O) [130-22-3] M 360.3. Commercial samples contain large amounts of sodium and potassium chlorides and sulphates. It is purified by passing through a Sephadex G-10 column, followed by elution with water, then 50% aq EtOH [King and Pruden Analyst 93 601 7968]. 

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