Amberlite®

Conversion of the salt of a weak base into the free base. Prepare a column of a strong base anion resin (such as Amberlite IRA-40o(OH) ) washed with distilled water as above. Drain off most of the water and then allow 100 ml. of A//2.Na.2C03 solution to pass through the column at 5 ml. per minute. Again wash the column with 200 ml. of distilled water. Dissolve 0-05 g. of aniline hydrochloride in 100 ml. of distilled water and pass the solution down the column. The effluent contains aniline in solution and free from all other ions. 

Amberlite and Duolite are trade names of Rohm Haas resins. 

Amberlite IRA-400 1.4 1.11 8% cross-linkage. Used for systems essentially free of organic materials. 

Amberlite IRA-402 1.3 1.07 Lower cross-linkage than IRA-400 better diffusion rate with large organic molecules. 

Amberlite IRA-410 1.4 1.12 Dimethylethanolamine functionality and slightly lower basicity than IRA-400. 

Amberlite IRA-458 1.2 1.08 Has an acrylic structure rather than S-DVB hence more hydrophilic and resistant to organic fouling. 

Amberlite IRA-68 1.6 1.06 Acrylic-DVB with unusually high capacity for large organic molecules. 

Amberlite IR-120 1.9 1.26 8% styrene-DVB type high physical stability. 

Amberlite DP-1 2.5 1.17 Methacrylic acid-DVB high resin capacity. Use pH >5. 

Amberlite IRC-50 3.5 1.25 Methacrylic acid-DVB. Selectivity adsorbs organic gases such as antibiotics, alkaloids, peptides, and amino acids. Use pH >5. 

Amberlite IRA-93 1.3 1.04 Styrene-DVB pH range is 0 to 9. Excellent resistance to oxidation and organic foul-... 

Amberlite LA-1 A secondary amine containing two highly branched aliphatic chains of M.W. 351 to 393. Solubility is 15 to 20 mg/mL in water. Used as 5 to 40% solutions in hydrocarbons. 

Amberlite IRA-402 Amberlite IRA-458 Amberlite IR-1180M Amberlite XAD Amberlite XAD-2 Amberlyst... 

Eig. 5. Pressure drop as affected by resin type, flow rate, and temperature, where A, B, and C, correspond respectively to acryUc strong base anion exchanger (Amberlite IRA-458), styrenic strong base anion exchanger (Amberlite IRA-402), and styrenic strong acid cation exchanger (Amberlite IR-120), all at 4°C. D represents styrenic strong acid cation resin (Amberlite IR-120) at 50°C (14). To convert kg/(cm -m) to lb/(in. -ft), multiply by 4.33 to convert... 

Purifications of elfamycins have been described in the Hterature using Craig distribution (2,34), chromatography on Sephadex LH-20 (2,14,26) and Amberlite XAD-2 (10,17,19,26), supercritical fluid extraction (37), and chromatography on an Ito multilayer cod planet centrifuge (26,38). and nmr assignments of most elfamycins have been accompHshed (3,24,26,32). The characteristic uv spectra permits some differentiation (12) and bathochromic shifts associated with Al " complexation have been used to quantify efrotomycin (2, R = CH ) in feed premixes (39,40). 

Recovery and Purification. The dalbaheptides are present in both the fermentation broth and the mycelial mass, from which they can be extracted with acetone or methanol, or by raising the pH of the harvested material, eg, to a pH of 10.5—11 for A47934 (16) (44) and A41030 (41) and actaplanin (Table 2) (28). A detailed review on the isolation of dalbaheptides has been written (14). Recovery from aqueous solution is made by ion pair (avoparcin) or butanol (teicoplanin) extraction. The described isolation schemes use ion-exchange matrices such as Dowex and Amberlite IR, acidic alumina, cross-linked polymeric adsorbents such as Diaion HP and Amberlite XAD, cation-exchange dextran gel (Sephadex), and polyamides in various sequences. Reverse-phase hplc, ion-exchange, or affinity resins may be used for further purification (14,89). 

Table 8. Adsorption Capacity of Amberlite XAD-4 Polymeric Resin ...

A series of tests using Amberlite IR-12 (sulfonated polystyrene resin) to esterify diethylene glycol (DEG) using toluene as the entrainer for removal of water gave the results in Table 1 (53). 

Table 1. Tests Using Amberlite IR-120 to Esterify Diethylene Glycol (DEG)...

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