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preface to fifteenth edition

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PRACTICAL LABORATORY INFORMATION 11.33<br />

TABLE 11.16<br />

Guide <strong>to</strong> Ion-Exchange Resins<br />

Dowex is the trade name of Dow resins; X (followed by a numeral) is percent cross-linked. Mesh size (dry)<br />

are available in the range 50 <strong>to</strong> 100, 100 <strong>to</strong> 200, 200 <strong>to</strong> 400, and sometimes minus 400.<br />

S-DVB is the acronym for styrene-divinylbenzene.<br />

MP is the acronym for macroporous resin. Mesh size (dry) is available in the range 20 <strong>to</strong> 50, 100 <strong>to</strong> 200,<br />

and 200 <strong>to</strong> 400.<br />

Bio-Rex is the trade name for certain resins sold by Bio-Rad Labora<strong>to</strong>ries.<br />

Amberlite and Duolite are trade names of Rohm & Haas resins.<br />

Resin type and<br />

nominal percent<br />

cross-linkage<br />

Minimum wet<br />

capacity,<br />

mequiv · mL 1<br />

Density<br />

(nominal),<br />

g·mL 1<br />

Comments<br />

Anion exchange resins9gel type9strongly basic9quaternary ammonium functionality<br />

Dowex 1-X2 0.6 0.65 Strongly basic anion exchanger with S-DVB<br />

matrix for separation of small peptides,<br />

nucleotides, and large metal complexes.<br />

Molecular weight exclusion is 2700.<br />

Dowex 1-X4 1.0 0.70 Strongly basic anion exchanger with S-DVB<br />

matrix for separation of organic acids,<br />

nucleotides, phosphoinositides, and other<br />

anions. Molecular weight exclusion is<br />

1400.<br />

Dowex 1-X8 1.2 0.75 Strongly basic anion exchanger with S-DVB<br />

matrix for separation of inorganic and organic<br />

anions with molecular weight exclusion<br />

1000. 100–200 mesh is standard<br />

for analytical separations.<br />

Dowex 2-X8 1.2 0.75 Strongly basic (but less basic than Dowex 1<br />

type) anion exchanger with S-DVB matrix<br />

for deionization of carbohydrates and<br />

separation of sugars, sugar alcohols, and<br />

glycosides.<br />

Amberlite IRA-400 1.4 1.11 8% cross-linkage. Used for systems essentially<br />

free of organic materials.<br />

Amberlite IRA-402 1.3 1.07 Lower cross-linkage than IRA-400; better<br />

diffusion rate with large organic molecules.<br />

Amberlite IRA-410 1.4 1.12 Dimethylethanolamine functionality and<br />

slightly lower basicity than IRA-400.<br />

Amberlite IRA-458 1.2 1.08 Has an acrylic structure rather than S-DVB;<br />

hence more hydrophilic and resistant <strong>to</strong><br />

organic fouling.<br />

Anion exchange resin–gel type9intermediate basicity<br />

Bio-Rex 5 2.8 0.70 Intermediate basic anion exchanger with<br />

primarily tertiary amines on a polyalkyleneamine<br />

matrix for separation of organic<br />

acids.

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