Analytical Grade Ion Exchange Resins

• AG^® 1 and AG^® 2 Anion Exchange Resins
• AG^® MP-1M Anion Exchange Resins
• Bio-Rex^® 5 Anion Exchange Resins
• AG^® 50W and AG^® MP-50 Cation Exchange Resins
• Bio-Rex^® 70 Cation Exchange Resins
• AG^® 501 Mixed-Bed Resins
• Chelex^® 100 Resin
• AG^® 11 A8 Resin
• Bio-Rex^® Reactor Grade Resins

Overview

Analytical grade resins are available as both strong and weak cation and anion exchangers and as mixed-bed ion exchangers. Many are available in several ionic forms and can be converted from one form to another.

Analytical Grade Resin Selection Guide

Analytical Grade Resin Selection Guide

Specifications of AG 1 and AG 2 Resins

Specifications of AG® 1 and AG® 2 Resins

AG 1 Resins
	Crosslinkage	Approx. MW Exclusion	Operating Stability/pH Range	Min. Wet Capacity (meq/ml)	Nominal Density (g/ml)	Ionic Forms
Type: Strong anion	2%	2,700	0–14/0–14	0.6	0.65	Chloride, acetate
Functional group: R-CH2N-(CH3)3	4%	1,400		1	0.7	Chloride
Matrix: Styrene divinylbenzene	8%	1,000		1.2	0.75	Chloride, hydroxide, acetate, formate

Applications: Exchange of anions of salts and ampholytes ion basic form (at pH>pl ). Lower crosslinkages are useful for higher molecular weight molecules, such as peptides, nucleotides, and uranium complexes. Higher crosslinkages are useful for low molecular weight inorganic anions and for applications such as cyclic nucleotide assays and fractionation of organic acids.

AG 2 Resins
	Crosslinkage	Approx. MW Exclusion	Operating Stability/pH Range	Min. Wet Capacity (meq/ml)	Nominal Density (g/ml)	Ionic Forms
Type: Strong anion	8%	1,000	0-14/0-14	1.2	0.75	Chloride
Functional group: R-CH2N-(CH3)3
Matrix: Styrene divinylbenzene

Applications: Similar to AG 1 resin but less basic and less resistant to oxidation, AG 2 resin is capable of separating sugars, sugar alcohols, and gluocosides. The isomerization of some sugars, which occurs with AG 1 resin, does not occur with AG 2 resin.

Physical Properties of AG Resins

Physical Properties of AG Resins

Resin Type	Active Group	Order of Selectivity	Thermal Stability	Solvent Stability	Resistance to Oxidizing Agents
AG 1 and AG MP-1 Resins	R-CH2N+(CH3)3	>phenolate >HSO4>CIO3 >NO3>Br> CN>HSO3>NO2>Cl> HCO3>IO3 H2COO>Ac> OH>F	OH- form, fair to 50°C; Cl- and other forms, good to 150°C	Very good	Slow solution in hot 15% HNO3 or conc. H2O2
AG2 Resin	R-CH2N+(CH3)2C2H4OH	phenolate>I >HSO4CIO3 >NO3>Br> CN>HSO3> NO2>Cl>OH >IO3>H2COO >Ac>F	OH- form, to 30°C; Cl- forms, good to 150°C	Very good	Slow solution in hot 15% HNO3 or conc. H2O2

Specifications of AG 11 A8 Resin

Specifications of AG® 11 A8 Resin

Resin	Crosslinkage	Approx. MW Exclusion	Operating Stability/pH Range	Min. Wet Capacity (meq/ml)	Nominal Density (g/ml)	Ionic Forms
Type: Ion retardation	8%	1,000	0–14/0–14	0.7	0.7	Self-adsorbed
Functional group: R-CH2N+(CH3)3 and R-CH2COO-
Matrix: Acrylic acid within styrene divinylbenzene
Applications: Contains paired anions and cation exchange sites. Selectively retards ionic substances. Useful for desalting nonionic substances and for ion removal from ionic substances; for example, removal of SDS from proteins and inorganic salts from amino acids.

Specifications of AG 50 Resin

Specifications of AG® 50 Resin

AG 50W Resins
Resin	Crosslinkage	Approx. MW Exclusion	Operating Stability/pH Range	Min. Wet Capacity (meq/ml)	Nominal Density (g/ml)	Ionic Forms
Type: Strong cation	2%	2,700	0–14/0–14	0.6	0.7	Hydrogen
Functional group: R-SO3-	4%	1,400		1.1	0.8	Hydrogen
Matrix: Styrene divinylbenzene	8% 12%	1,000 400		1.7 2.1	0.80 .085	Hydrogen
						Hydrogen
Applications: Lower crosslinkage resins are used for separation or concentration of peptides, nucleotides, and amino acids. Higher crosslinkage resins are useful for separations of smaller peptides and amino acids, removal of cation, and separation of metal ions.

AG MP-50 Resin
Resin	Crosslinkage	Approx. MW Exclusion	Operating Stability/pH Range	Min. Wet Capacity (meq/ml)	Nominal Density (g/ml)	Ionic Forms
Type: Strong cation	Macroporous	>1,000,000	0-14/0-14	1.5	0.8	Hydrogen
Functional group: R-SO3-
Matrix: Styrene divinylbenzene
Applications: Macroporous equivalent of AG 50W resin. Its effective surface area is approximately 35 m2 per dry gram, which is equivalent to 30-35% porosity. It can be used for adsorption of Ca2+, Mg2+, Na2+, and antibiotics.

Selectivity of Counterions

Relative Selectivity of Various Counterions on Selected AG Resins

AG 50W-X8 Resin		AG 1-X8 Resin
Counterion	Relative Selectivity	Counterion	Relative Selectivity
H+	1.0	OH–	1.0
Li+	0.85	F–	1.6
Na+	1.5	Propionate	2.6
NH4+	1.95	Acetate	3.2
Mn2+	2.35	Formate	4.6
K+	2.5	HPO4 –	5.0
Mg2+	2.5	IO3 –	5.5
Fe2+	2.55	HCO3 –	6.0
Rb+	2.6	Cl–	22
Cs+	2.7	NO2 –	24
Zn2+	2.7	BrO3 –	27
Co2+	2.8	HSO3 –	27
Cu2+	2.9	CN–	28
Cd2+	2.95	Br–	50
Ni2+	3.0	NO3 –	65
Ca2+	3.9	ClO3 –	74
Sr2+	4.95	HSO4 –	85
Cu+	5.3	Phenate	110
Hg2+	7.2	I–	175
Pb2+	7.5	Citrate	220
Ag+	7.6	Salicylate	450
Ba2+	8.7	Benzenesulfonate	500

AG 501-X8 Resin Properties

AG® 501-X8 Resin Properties

	AG 501-X8 Resin	AG 5010-X8 (D) Resin	Bio-Rex MSZ 501(D) Resin
Chemical form	H+ & OH-	H+ & OH-	H+ & OH-
Resin Type	Mixed bed	Mixed bed	Mixed bed
Physical form	Light and dark gold beads	Blue and gold beads	Blue and brown beads
Minimum total capacity	1.5 meq/ml	1.5 meq/ml	1.5 meq/ml
Particle diameter	300–1,180 µm	300–1,180 µm	600±100 µm
Mesh size	20–50	20–50	25–35
Matrix	Styrene divinylbenzene	Styrene divinylbenzene	Styrene divinylbenzene

Selecting Cation or Anion

Selecting Cation or Anion Exchange Support

Separation strategy for amphoteric molecules. If the molecule is stable at a pH above its pl, an anion exchange support is used. If the molecule is stable at a pH below its pl, a cation exchange support is used.

Stability to Various Treatments

Stability of Selected Analytical Grade Resins to Various Treatments

Resin	Heat*	Solvents (Alcohols, Hydrocarbons, etc.)	Oxidation	Reduction
AG 1	OH- form, fair to 50°C Cl- and other forms, good to 150°C	Very good	Slowly dissolves in hot 15% HNO3 or concentrated H2O2	Good**
AG 2	OH- form, fair to 30°C Cl- form, good to 150°C	Very good	Slowly dissolves in hot 15% HNO3	Good**
AG 50W	Good to 150°C	Very good	Slowly dissolves in hot 15% HNO3	Very good
AG 4-X4	Good to 60°C	Good	Good	Unknown
AG 501-X8	Good to 50°C	Very good	Slowly dissolves in hot 15% HNO3 or concentrated H2O2	Good**
AG 11 A8	Good to 100°C	Good	Slowly dissolves in hot 15% HNO3 or concentrated H2O2	Good
Bio-Rex 5	Good to 60°C	Good	Good	Excellent
Bio-Rex 70	Good to 100°C	Good	Good	Good
Bio-Rex MSZ 501(D)	Good to 50°C	Very good	Slowly dissolves in hot 15% HNO3 or concentrated H2O2	Good**
Chelex 100	Good to 75°C	Good	Breaks down in strong oxidizing agents	Unknown

* All anion resins may be autoclaved except the CH- form; all cation exchange resins may be autoclaved.
** AG 1, AG 2, AG 501, and Bio-Rex MSZ 501 (D) resins will slowly break down in the presence of sulfur-containing reducing agents.

AG Resin Wet Mesh and Diameters

AG Resin Wet Mesh and Diameters

Wet mesh (U.S. Standards)	16	20	40	50	80	100	140	200	270	325	400
Diameter, µm	1,180	850	425	300	180	150	106	75	53	45	38

Category Products

AG® 1 and AG® 2 Anion Exchange Resins AG resins are highly purified to remove both organic and inorganic impurities. Resins are sized to consistently give narrow wet mesh ranges, which provide high resolution and excellent reproducibility.

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AG® MP-1M Anion Exchange Resins AG resins are highly purified to remove both organic and inorganic impurities. Resins are sized to consistently give narrow wet mesh ranges, which provide high resolution and excellent reproducibility.

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Bio-Rex® 5 Anion Exchange Resins Bio-Rex 5 resins are weak anion exchangers that contain primarily tertiary, but also some quaternary, amines on a styrenedivinylbenzene lattice. They have an affinity for organic acids.

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AG® 50W and AG® MP-50 Cation Exchange Resins The AG 50W resin, AG MP-50 macroporous resin, and the biotechnology grade AG 50W resin all offer strong acid cation exchange capabilities.

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Bio-Rex® 70 Cation Exchange Resins Bio-Rex 70 resins are weak cation exchangers that are used for the purification and fractionation of peptides, proteins, antibiotics, and other cationic molecules.

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AG® 501 Mixed-Bed Resins AG 501-X8 and Bio-Rex MSZ 501 (D) resins are mixed-bed resins containing equivalent amounts of AG 50W-X8 strong cation exchange resin (H+ form) and AG 1-X8 strong anion exchange resin (OH- form).

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Chelex® 100 Resin Chelex 100 resin is a styrene divinylbenzene copolymer containing paired iminodiacetate ions, which act as chelating groups in binding polyvalent metal ions.

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AG® 11 A8 Resin AG 11 A8 ion retardation resin is extremely useful for chromatographic desalting, or removing acid from non-ionic molecules.

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Bio-Rex® Reactor Grade Resins Bio-Rad offers reactor grade Bio-Rex RG 501-X8 resins for power plant deionization systems and large-scale cleanup of metals from wastewater.

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