Cibacron Blue F3GA‐attached magnetic poly(2‐hydroxyethyl methacrylate) beads for human serum albumin adsorption

An affinity dye ligand, Cibacron Blue F3GA, was covalently attached onto magnetic poly(2‐hydroxyethyl methacrylate) (mPHEMA) beads for human serum albumin (HSA) adsorption from both aqueous solutions and human plasma. The mPHEMA beads, in the size range of 80 to 120 µm, were prepared by a modified suspension technique. Cibacron Blue F3GA molecules were incorporated on to the mPHEMA beads. The maximum amount of Cibacron Blue F3GA attachment was obtained as 68.3 µmol g^?1. HSA adsorption onto unmodified and Cibacron Blue F3GA‐attached mPHEMA beads was investigated batchwise. The non‐specific adsorption of HSA was very low (1.8 mg g^?1). Cibacron Blue F3GA attachment onto the beads significantly increased the HSA adsorption (94.5 mg g^?1). The maximum HSA adsorption was observed at pH 5.0. Higher HSA adsorption was observed from human plasma (138.3 mg HSA g^?1). Desorption of HSA from Cibacron Blue F3GA‐attached mPHEMA beads was obtained by using 0.1 M Tris/HCl buffer containing 0.5 M NaSCN. High desorption ratios (up to 98% of the adsorbed HSA) were observed. It was possible to re‐use Cibacron Blue F3GA‐attached mPHEMA beads without any significant decreases in their adsorption capacities. Copyright © 2004 Society of Chemical Industry     

Preparation of Zn2+‐chelated poly(HEMA‐MAH) cryogel for affinity purification of chicken egg lysozyme

Supermacroporous poly(2‐hydroxyethyl methacrylate) [poly(HEMA)]‐based monolithic cryogel column was prepared by radical cryocopolymerization of HEMA with N‐methacryloyl‐L ‐histidine methyl ester (MAH) as functional comonomer and N,N′‐methylene‐bisacrylamide (MBAAm) as crosslinker directly in a plastic syringe for affinity purification of lysozyme from chicken egg white. The monolithic cryogel containing a continuous polymeric matrix having interconnected pores of 10–50 μm size was loaded with Zn²⁺ ions to form the metal chelate with poly(HEMA‐MAH) cryogel. Poly(HEMA‐MAH) cryogel was characterized by swelling studies, FTIR, scanning electron microscopy, and elemental analysis. The equilibrium swelling degree of the poly(HEMA‐MAH) monolithic cryogel was 5.62 g H₂O/g cryogel. Poly(HEMA‐MAH) cryogel containing 45.8 μmol MAH/g was used in the adsorption/desorption of lysozyme from aqueous solutions. The nonspecific adsorption of lysozyme was very low (7.5 mg/g). The maximum amount of lysozyme adsorption from aqueous solution in phosphate buffer was 209 mg/g at pH 7.0. It was observed that lysozyme could be repeatedly adsorbed and desorbed with the poly(HEMA‐MAH) cyogel without significant loss of adsorption capacity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Metal‐chelated polyamide hollow fibers for human serum albumin separation

We modified microporous polyamide hollow fibers by acid hydrolysis to amplify the reactive groups and subsequent binding of Cibacron Blue F3GA. Then, we loaded the Cibacron Blue F3GA‐attached hollow fibers with different metal ions (Cu²⁺, Ni²⁺, and Co²⁺) to form the metal chelates. We characterized the hollow fibers by scanning electron microscopy. The effect of pH and initial concentration of human serum albumin (HSA) on the adsorption of HSA to the metal‐chelated hollow fibers were examined in a batch system. Dye‐ and metal‐chelated hollow fibers had a higher HSA adsorption capacity and showed less nonspecific protein adsorption. The nonspecific adsorption of HSA onto the polyamide hollow fibers was 6.0 mg/g. Cibacron Blue F3GA immobilization onto the hollow fibers increased HSA adsorption up to 147 mg/g. Metal‐chelated hollow fibers showed further increases in the adsorption capacity. The maximum adsorption capacities of Co²⁺‐, Cu²⁺‐, and Ni²⁺‐chelated hollow fibers were 195, 226, and 289 mg/g, respectively. The recognition range of metal ions for HSA from human serum followed the order: Ni(II) > Cu(II) > Co(II). A higher HSA adsorption was observed from human serum (324 mg/g). A significant amount of the adsorbed HSA (up to 99%) was eluted for 1 h in the elution medium containing 1.0M sodium thiocyanide (NaSCN) at pH 8.0 and 25 mM ethylenediaminetetraacetic acid at pH 4.9. Repeated adsorption–desorption processes showed that these metal‐chelated polyamide hollow fibers were suitable for HSA adsorption. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3346–3354, 2002     

Dye‐ligand column chromatography: Albumin adsorption from aqueous media and human plasma with dye‐affinity microbeads

Cibacron Blue F3GA was covalently coupled with poly(ethylene glycol‐dimethacrylate‐2‐hydroxyethylmethacrylate) [poly(EGDMA‐HEMA)] microbeads via the nucleophilic substitution reaction between the chloride of its triazine ring and the hydroxyl groups of the HEMA molecules under alkaline conditions. The affinity sorbent carrying 16.5 μmol Cibacron Blue F3GA/g polymer was then used for bovine serum albumin (BSA) adsorption from aqueous protein solutions and from human plasma in a packed‐bed column. The BSA adsorption capacity of the microbeads decreased with an increase in the recirculation rate. High adsorption rates were observed at the beginning, then equilibrium was gradually achieved in about 60 min. The BSA concentration in the mobile phase was also effective on adsorption. BSA adsorption was first increased with BSA concentration, then reached a plateau that was about 57.3 mg BSA/g. Higher BSA adsorption was observed at lower ionic strength. The maximum adsorption was observed at pH 5.0, which is the isoelectric pH of BSA. Higher human serum albumin adsorption was achieved from human plasma (109.6 mg HSA/g). High desorption ratios (over 94% of the adsorbed albumin) were achieved by using 1.0M NaSCN (pH 8.0) in 30 min. It was observed that albumin could be repeatedly adsorbed and desorbed without a significant loss in adsorption capacity. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2803–2810, 1999     

Metal chelating properties of Cibacron Blue F3GA‐derived poly(EGDMA‐HEMA) microbeads

Metal chelating properties of Cibacron Blue F3GA‐derived poly(EGDMA‐HEMA) microbeads have been studied. Poly(EGDMA‐HEMA) microbeads were prepared by suspension copolymerization of ethylene glycol dimethacrylate (EGDMA) and hydroxy‐ethyl methacrylate (HEMA) by using poly(vinyl alcohol), benzoyl peroxide, and toluene as the stabilizer, the initiator, and the pore‐former, respectively. Cibacron Blue F3GA was covalently attached to the microbeads via the nucleophilic substitution reaction between the chloride of its triazine ring and the hydroxyl groups of the HEMA, under alkaline conditions. Microbeads (150–200 μm in diameter) with a swelling ratio of 55%, and carrying 16.5 μmol Cibacron Blue F3GA/g polymer were used in the adsorption/desorption studies. Adsorption capacity of the microbeads for the selected metal ions, i.e., Cu(II), Zn(II), Cd(II), Fe(III), and Pb(II) were investigated in aqueous media containing different amounts of these ions (5–200 ppm) and at different pH values (2.0–7.0). The maximum adsorptions of metal ions onto the Cibacron Blue F3GA‐derived microbeads were 0.19 mmol/g for Cu(II), 0.34 mmol/g for Zn(II), 0.40 mmol/g for Cd(II), 0.91 mmol/g for Fe(III), and 1.05 mmol/g for Pb(II). Desorption of metal ions were studied by using 0.1 M HNO₃. High desorption ratios (up to 97%) were observed in all cases. Repeated adsorption/desorption operations showed the feasibility of repeated use of this novel sorbent system. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1397–1403, 1999     

Nonporous monosize polymeric sorbents: Dye and metal chelate affinity separation of lysozyme

Lysozyme adsorption onto dye‐attached nonporous monosize poly(2‐hydroxyethyl‐methacrylate‐methylmethacrylate) [poly(HEMA‐MMA)] microspheres was investigated. Poly(HEMA‐MMA) microspheres were prepared by dispersion polymerization. The monochloro‐triazine dye, Cibacron Blue F3GA, was immobilized covalently as dye–ligand. These dye‐affinity microspheres were used in the lysozyme adsorption–desorption studies. The effect of initial concentration of lysozyme and medium pH on the adsorption efficiency of dye‐attached and metal‐chelated microspheres were studied in a batch reactor. Effect of Cu(II) chelation on lysozyme adsorption was also studied. The nonspecific adsorption of lysozyme on the poly(HEMA‐MMA) microspheres was 3.6 mg/g. Cibacron Blue F3GA attachment significantly increased the lysozyme adsorption up to 247.8 mg/g. Lysozyme adsorption capacity of the Cu(II) incorporated microspheres (318.9 mg/g) was greater than that of the Cibacron Blue F3GA‐attached microspheres. Significant amount of the adsorbed lysozyme (up to 97%) was desorbed in 1 h in the desorption medium containing 1.0M NaSCN at pH 8.0 and 25 mM EDTA at pH 4.9. In order to examine the effects of separation conditions on possible conformational changes of lysozyme structure, fluorescence spectrophotometry was employed. We conclude that dye‐ and metal‐chelate affinity chromatography with poly(HEMA‐MMA) microspheres can be applied for lysozyme separation without causing any significant changes and denaturation. Repeated adsorption/desorption processes showed that these novel dye‐attached monosize microspheres are suitable for lysozyme adsorption. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 115–124, 2000     

Albumin adsorption from aqueous solutions and human plasma in a packed-bed column with Cibacron Blue F3GA-Zn(II) attached poly(EGDMA-HEMA) microbeads

Affinity dye-ligand Cibacron Blue F3GA, was covalently coupled with poly(EGDMA-HEMA) microbeads via nucleophilic reaction between the chloride of its triazine ring and the hydroxyl groups of the HEMA under alkaline conditions. The microbeads carrying 16.5 μmol Cibacron Blue F3GA per gram polymer was incorporated with Zn(II) ions. Zn(II) loading was 189.6 μmol/g. Cibacron Blue F3GA-Zn(II) attached affinity sorbent was used for albumin adsorption from aqueous solutions and human plasma in a packed-bed column. BSA adsorption capacity of the microbeads decreased with an increase in the recirculation rate. High adsorption rates were observed at the beginning, then equilibrium was gradually achieved in about 60 min. The BSA concentration in the mobile phase also effected adsorption. BSA adsorption was first increased with BSA concentration, then reached a plateau which was about 128 mg BSA/g. The maximum adsorption was observed at pH 5.0 which is the isoelectric pH of BSA. Higher human serum albumin adsorption was observed from human plasma (215 mg HSA/g). High desorption ratios (over 90% of the adsorbed albumin) were achieved by using 1.0 M NaSCN (pH 8.0) in 30 min.     

Preparation of cibacron blue F3GA‐attached polyamide hollow fibers for heavy metal removal

Dye‐affinity adsorption has been used increasingly for heavy metal removal. Synthetic hollow fibers have advantages as support matrices in comparison to conventional bead supports because they are not compressible and they eliminate internal diffusion limitations. The goal of this study was to investigate in detail the performance of hollow fibers composed of modified polyamide to which Cibacron Blue F3GA was attached for the removal of heavy metal ions. The Cibacron Blue F3GA loading was 1.2 mmol/g. The internal matrix was characterized by scanning electron microscopy. No significant changes in the hollow fiber cross‐section or outer layer morphology were observed after dye modification. The effect of the initial concentration of heavy metal ions and medium pH on the adsorption efficiency were studied in a batch reactor. The adsorption capacity of the hollow fibers for the selected metal ions [i.e., Cu(II), Zn(II) and Ni(II)] were investigated in aqueous media with different amounts of these ions (10–400 ppm) and at different pH values (3.0–7.0). The maximum adsorptions of metal ions onto the Cibacron Blue F3GA‐attached hollow fibers were 246.2 mg/g for Cu(II), 133.6 mg/g for Zn(II), and 332.7 mg/g for Ni(II). Furthermore, a Langmuir expression was calculated to extend the adsorption equilibrium. Nitric acid (0.1M) was chosen as the desorption solution. High desorption ratios (up to 97%) were observed in all cases. Consecutive adsorption/desorption operations showed the feasibility of repeated use of this novel sorbent system. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 3089–3098, 2002; DOI 10.1002/app.2338     

New metal chelate sorbent for albumin adsorption: Cibacron Blue F3GA-Zn(II) attached microporous poly(HEMA) membranes

Poly(2-hydroxyethyl methacrylate) [poly(HEMA)] membranes were prepared by UV-initiated photopolymerization of HEMA in the presence of an initiator (α-α′-azobis-isobutyronitrile, AIBN). The triazine dye Cibacron Blue F3GA was attached as an affinity ligand to poly(HEMA) membranes, covalently. These affinity membranes with a swelling ratio of 58% and containing 10.7 mmol Cibacron Blue F3GA/m² were used in the albumin adsorption studies. After dye-attachment, Zn(II) ions were chelated within the membranes via attached-dye molecules. Different amounts of Zn(II) ions [650–1440 mg Zn(II)/m²] were loaded on the membranes by changing the initial concentration of Zn(II) ions and pH. Bovine serum albumin (BSA) adsorption on these membranes from aqueous solutions containing different amounts of BSA at different pH was investigated in batch reactors. The nonspecific adsorption of BSA on the poly(HEMA) membranes was negligible. Cibacron Blue F3GA attachment significantly increased the BSA adsorption up to 92.1 mg BSA/m². Adsorption capacity was further increased when Zn(II) ions were attached (up to 144.8 mg BSA m²). More than 90% of the adsorbed BSA was desorbed in 1 h in the desorption medium containing 0.5M NaSCN at pH 8.0 and 0.025M EDTA at pH 4.9. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 657–664, 1998     

Human serum albumin (HSA) adsorption with chitosan microspheres

In this study, chitosan microspheres were prepared and characterized for adsorption of human serum albumin (HSA) as affinity sorbent. The chitosan microspheres were obtained with a “suspension crosslinking technique” in the size range of 30–700 μm by using a crosslinker, i.e., glutaraldehyde. The chitosan microspheres used in HSA adsorption studies were having the average size of 170 ± 81 μm. Adsorption medium pH and the initial HSA concentration in the adsorption medium were changed as 4.0–7.0 and 0.5–2.0 mg HSA/mL, respectively, to investigate the HSA adsorption capacity of chitosan microspheres. Maximum HSA adsorption (i.e., 11.35 mg HSA/g chitosan microspheres) was obtained at pH 5.0 and 1.5 mg HSA/mL of the initial HSA concentration in the adsorption medium was obtained as the saturation value for HSA adsorption. A very common dye ligand, i.e., Cibacron Blue F3GA was attached to the chitosan microspheres to increase the HSA adsorption capacity. Actually, the HSA adsorption capacity was increased up to 15.35 mg HSA/g chitosan microspheres in the case of Cibacron Blue F3GA attached to chitosan microspheres used. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3035–3039, 2002     

Affinity adsorption of recombinant human interferon‐α on monosize dye‐affinity beads

Monosize, nonporous poly(glycidyl methacrylate) [poly(GMA)] beads were prepared by dispersion polymerization. Cibacron Blue F3GA was covalently attached onto the poly(GMA) beads for adsorption of recombinant interferon‐α (rHuIFN‐α). Monosize poly(GMA) beads were characterized by scanning electron microscopy. Dye‐carrying beads (1.73 mmol/g) were used in the adsorption–elution studies. The effect of initial concentration of rHuIFN‐α, pH, ionic strength, and temperature on the adsorption efficiency was studied in a batch system. Nonspecific adsorption of rHuIFN‐α on the beads was 0.78 mg/g. Dye attachment significantly increased the rHuIFN‐α adsorption up to 181.7 mg/g. Equilibrium adsorption of rHuIFN‐α onto the dye‐carrying beads increased with increasing temperature. Negative change in free energy (ΔG⁰ < 0) indicated that the adsorption was a thermodynamically favorable process. ΔS and ΔH values were 146.1 J/mol K and ?37.39 kJ/mol, respectively. Significant amount of the adsorbed rHuIFN‐α (up to 97.2%) was eluted in the elution medium containing 1.0M NaCl in 1 h. To determine the effects of adsorption conditions on possible conformational changes of rHuIFN‐α structure, fluorescence spectrophotometry was employed. We concluded that dye‐affinity beads can be applied for rHuIFN‐α adsorption without causing any significant conformational changes. Repeated adsorption–elution processes showed that these beads are suitable for rHuIFN‐α adsorption. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 975–981, 2007     

Reactive green HE‐4BD functionalized supermacroporous poly(hydroxyethyl methacrylate) cryogel for heavy metal removal

The aim of this study was to investigate the heavy metal adsorption performance of supermacroporous poly(hydroxyethyl methacrylate) [PHEMA] cryogel. The PHEMA cryogel was produced by cryo‐polymerization. The PHEMA cryogel was characterized by scanning electron microscopy (SEM). The PHEMA cryogel containing 385 μmol Reactive Green HE‐4BD/g were used in the adsorption studies. Adsorption capacity of the PHEMA cryogel for the metal ions, i.e., Cu²⁺, Cd²⁺, and Pb²⁺ were investigated in aqueous media containing different amounts of the ions (5–600 mg/L) and at different pH values (3.2–6.9). The maximum adsorption capacities of the PHEMA cryogel were 11.6 mg/g (56 μmol/g) for Pb²⁺, 24.5 mg/g (385 μmol/g) for Cu²⁺ and 29.1 mg/g (256 μmol/g) for Cd²⁺. The competitive adsorption capacities were 10.9 mg/g (52 μmol/g) for Pb²⁺, 22.1 mg/g for Cd²⁺ (196 μmol/g) and 23.2 mg/g (365 μmol/g) for Cu²⁺. The PHEMA/Reactive Green HE‐4BD cryogel exhibited the following metal ion affinity sequence on molar basis: Cu²⁺ > Cd²⁺ > Pb²⁺. The PHEMA/Reactive Green HE‐4BD cryogel can be easily regenerated by 50 mM EDTA with higher effectiveness. These features make the PHEMA/Reactive Green HE‐4BD cryogel a potential adsorbent for heavy metal removal. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Porous dye affinity beads for albumin separation from human plasma

Porous polymeric beads were obtained by the suspension polymerization of 2‐hydroxyethyl methacrylate (HEMA) and ethylene glycol dimethacrylate (EGDMA). Poly(HEMA–EGDMA) beads were characterized by surfacearea measurements, swelling studies, FTIR, scanning electron microscopy (SEM), and elemental analysis. Poly (HEMA–EGDMA) beads had a specific surface area of 56 m²/g. SEM observations showed that the poly(HEMA–EGDMA) beads abounded macropores. Poly(HEMA–EGDMA) beads with a swelling ratio of 55%, and containing different amounts of Reactive Red 120 (9.2–39.8 μmol/g) were used in the adsorption/desorption of human serum albumin (HSA) from aqueous solutions and human plasma. The nonspecific adsorption of HSA was very low (0.2 mg/g). The maximum HSA adsorption amount from aqueous solution in phosphate buffer was 60.1 mg/g at pH 5.0. Higher HSA adsorption value was obtained from human plasma (up to 95.7 mg/g) with a purity of 88%. The equilibrium monolayer adsorption amount, Q_max was determined as 172.4 mg/g. The dimensionless separation factor (R_L) value shows that the adsorption behavior of HSA onto the Reactive Red 120 attached poly(HEMA–EGDMA) beads was favorable (0 < R_L < 1). Desorption of HSA from Reactive Red 120 attached poly (HEMA–EGDMA) beads was performed using 0.1M Tris/HCl buffer containing 0.5M NaCl. It was observed that HSA could be repeatedly adsorbed and desorbed with Reactive Red 120‐attached poly(HEMA–EGDMA) beads without significant loss in the adsorption amount. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Affinity microspheres and their application to lysozyme adsorption: Cibacron Blue F3GA and Cu(II) with poly(HEMA-EGDMA)

Lysozyme adsorption onto Cibacron Blue F3GA attached and Cu(II) incorporated poly(2-hydroxyethyl methacrylate–ethylene glycol dimethacrylate) [poly(HEMA-EGDMA)] microspheres was investigated. The microspheres were prepared by suspension polymerization. Various amounts of Cibacron Blue F3GA were attached covalently onto the microspheres by changing the initial concentration of dye in the reaction medium. The microspheres with a swelling ratio of 65%, and carrying different amounts of dye (between 1.4 and 22.5 µmol/g⁻¹) were used in the lysozyme adsorption studies. Lysozyme adsorption on these microspheres from aqueous solutions containing different amounts of lysozyme at different pH values was investigated in batch reactors. The lysozyme adsorption capacity of the dye–metal chelated microspheres (238.2 mg g⁻¹) was greater than that of the dye-attached microspheres (175.1 mg g⁻¹). The maximum lyzozyme adsorption capacities (q_m) and the dissociation constant (k_d) values were found to be 204.9 mg g⁻¹ and 0.0715 mg ml⁻¹ with dye-attached and 270.7 mg g⁻¹ and 0.0583 mg ml⁻¹ with dye–metal chelated microspheres, respectively. More than 90% of the adsorbed lysozyme were desorbed in 60 min in the desorption medium containing 0.5 M KSCN at pH 8.0 or 25 mM EDTA at pH 4.9. © 1999 Society of Chemical Industry     

Comparison of metal chelate affinity sorption of BSA onto Dye/Zn (II)-derived poly(ethylene glycol dimethacrylate-hydroxyethyl methacrylate) microbeads

Poly(ethylene glycol dimethacrylate-hydroxyethyl methacrylate) [poly-(EGDMA-HEMA)]microbeads in the size range of 150–200 μm were produced by a modified suspension copolymerization of EGDMA and HEMA. The dyes (Congo red, Cibacron blue F3GA, and alkali blue 6B) were covalently immobilized; then, Zn(II) ions were incorporated within the microbeads by chelation with the dye molecules. The maximum amounts of dye loadings were 14.5 μmol/g, 16.5 μmol/g, and 23.7 μmol/g for Congo red, Cibacron blue F3GA, and alkali blue 6B, respectively. Different amounts of Zn(II) ions(2.9–53.8 mg/g polymer) were incorporated on the microbeads by changing the initial concentration of Zn(II) ions and the pH of the medium. Bovine serum albumin (BSA) adsorption onto dye/Zn(II)-derived microbeads containing Congo red, Cibacron blue F3GA, and alkali blue 6B was investigated. The maximum BSA adsorptions onto the dye/Zn(II)-derived microbeads from aqueous solutions containing different amounts of BSA were 159 mg/g, 122 mg/g, and 93 mg/g for the Congo red, Cibacron blue F3GA, and alkali blue 6B dyes, respectively. The maximum BSA adsorptions were observed at pH 6.0 in all cases. Desorption of BSA molecules was achieved by using 0.025M EDTA (pH 4.9). High desorption ratios (more than 93% of the adsorbed BSA) were observed in all cases. It was possible to reuse these novel metal chelate sorbents without significant losses in their adsorption capacities. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2085–2093, 1997     

Antibody purification using porous metal–chelated monolithic columns

A novel monolithic material was developed to obtain efficient and cost‐effective purification of IgG from human plasma. The porous monolith was obtained by bulk polymerization in a glass tube of 2‐hydroxyethyl methacrylate (HEMA) and N‐methacryloyl‐(L )‐histidine methyl ester (MAH). The poly(HEMA‐MAH) monolith had a specific surface area of 214.6 m²/g and was characterized by swelling studies, porosity measurement, FTIR, scanning electron microscopy, and elemental analysis. Then the monolith was loaded with Cu²⁺ ions to form the metal chelate. Poly(HEMA‐MAH) monolith with a swelling ratio of 74% and containing 20.9 μmol MAH/g was used in the adsorption/desorption of IgG from aqueous solutions and human plasma. The maximum adsorption of IgG from an aqueous solution in phosphate buffer was 10.8 mg/g at pH 7.0. Higher adsorption was obtained from human plasma (up to 104.2 mg/g), with a purity of 94.1%. It was observed that IgG could be repeatedly adsorbed and desorbed with the poly(HEMA‐MAH) monolith without significant loss of adsorption capacity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 395–404, 2006     

Packed-bed columns with dye-affinity microbeads for removal of heavy metal ions from aquatic systems

A dye ligand Cibacron Blue F3GA, was covalently coupled with polyhydroxyethylmethacrylate (PHEMA) microbeads in the 150–200 μm particle size range. The sorbent carrying 22.3 μmol Cibacron Blue F3GA per gram of polymer was then used to remove Pb(II), Cd(II), Cu(II) and Zn(II) from aqueous solutions in a packed-bed column system. Heavy metal ion adsorption capacity of the column was investigated as a function of heavy metal ion-bearing solution flow rate and the inlet heavy metal ion concentration. The maximum metal ion uptake values found were: 80.60, 96.98, 78.36, 103.98 μmol/g polymer for Pb(II), Cd(II), Cu(II) and Zn(II), respectively. The heavy metal adsorption capacity of the microbeads decreased with an increase in the circulation rate of aqueous solution. The order of affinity based on molar uptake was Zn(II)>Cd(II)>Pb(II)>Cu(II). Removal percentages of heavy metals related to flow time were determined for different flow rates and initial metal ion concentrations. It was observed that PHEMA microbeads carrying Cibacron Blue F3GA can be regenerated by washing with a solution of nitric acid (0.05 M). The desorption ratio was as high as 98.5%.     

Synthesis and characterization of poly(ethylene glycol dimethacrylate–1‐vinyl‐1,2,4‐triazole) copolymer beads for heavy‐metal removal

We prepared poly(ethylene glycol dimethacrylate–1‐vinyl‐1,2,4‐triazole) [poly(EGDMA–VTAZ)] beads (average diameter = 150–200 μm) by copolymerizing ethylene glycol dimethacrylate (EGDMA) with 1‐vinyl‐1,2,4‐triazole (VTAZ). The copolymer composition was characterized by elemental analysis and found to contain five EGDMA monomer units for each VTAZ monomer unit. The poly(EGDMA–VTAZ) beads had a specific surface area of 65.8 m²/g. Poly(EGDMA–VTAZ) beads were characterized by Fourier transform infrared spectroscopy, elemental analysis, surface area measurements, swelling studies, and scanning electron microscopy. Poly(EGDMA–VTAZ) beads with a swelling ratio of 84% were used for the heavy‐metal removal studies. The adsorption capacities of the beads for Cd(II), Hg(II), and Pb(II) were investigated in aqueous media containing different amounts of these ions (5–750 mg/L) and at different pH values (3.0–7.0). The maximum adsorption capacities of the poly(EGDMA–VTAZ) beads were 85.7 mg/g (0.76 mmol/g) for Cd(II), 134.9 mg/g (0.65 mmol/g) for Pb(II), and 186.5 mg/g (0.93 mmol/g) for Hg(II). The affinity order toward triazole groups on a molar basis was observed as follows: Hg(II) > Cd(II) > Pb(II). pH significantly affected the adsorption capacity of the VTAZ‐incorporated beads. The equilibrium data were well fitted to the Redlich–Peterson isotherm. Consideration of the kinetic data suggested that chemisorption processes could have been the rate‐limiting step in the adsorption process. Regeneration of the chelating‐beads was easily performed with 0.1M HNO₃. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4276–4283, 2006     

Preparation of a novel metal‐chelate affinity beads for albumin isolation from human plasma

In this study, we developed a novel approach to obtain a high protein‐adsorption capacity utilizing 2‐methacryloylamidohistidine (MAH) as a biollgand. MAH was synthesized by reacting methacryloyl chloride and histidine. Spherical beads, with an average size of 150–200 μm, were obtained by the radical suspension polymerization of MAH, ethyleneglycol dimethacrylate (EGDMA), and 2‐hydroxyethyl methacrylate (HEMA) conducted in an aqueous dispersion medium. p(EGDMA–HEMA–MAH) beads had a specific surface area of 17.6 m²/g. The synthesized MAH monomer was characterized by NMR. p(EGDMA–HEMA–MAH) beads were characterized by a swelling test, FTIR, and elemental analysis. Then, Cu(II) ions were incorporated into the beads and Cu(II) loading was found to be 0.96 mmol/g. These beads, with a swelling ratio of 65% and containing 1.6 mmol MAH/g, were used in the adsorption/desorption of human serum albumin (HSA) from both aqueous solutions and human serum. The adsorption of HSA onto p(EGDMA–HEMA–MAH) was low (8.8 mg/g). Cu(II) chelation onto the beads significantly increased the HSA adsorption (56.3 mg/g). The maximum HSA adsorption was observed at pH 8.0 Higher HSA adsorption was observed from human serum (94.6 mg HSA/g). Adsorptions of other serum proteins were obtained as 3.7 mg/g for fibrinogen and 8.5 mg/g for γ‐globulin. The total protein adsorption was determined as 107.1 mg/g. Desorption of HSA was obtained using a 0.1M Tris/HCI buffer containing 0.5M NaSCN. High desorption ratios (to 98% of the adsorbed HSA) were observed. It was possible to reuse Cu(II)‐chelated p(EGDMA–HEMA–MAH) beads without significant decreases in the adsorption capacities. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2840–2847, 2003     

N‐acetyl‐D‐galactosamine‐specific lectin isolation from soyflour with poly(HPMA‐GMA) beads

Soybean lectin was purified from seeds of Glycine max L.Merrill SA88. Poly(hydroxypropyl methacrylate‐glycidyl methacrylate) [poly(HPMA‐GMA)] beads were used as an affinity matrix and N‐acetyl‐D ‐galactosamine (GalNAc) was used as an affinity ligand. Soybean lectin adsorption with GalNAc attached poly(HPMA‐GMA) beads from soybean lectin solution (in phosphate buffered saline) was 5.0 mg/g. Maximum adsorption capacity for soybean lectin from the soy flour extract was 26.0 mg/g. Elution of soybean lectin from adsorbent was accomplished by 0.5M galactose solution. Purity of soybean lectin was determined by SDS‐PAGE. It was observed that soybean lectin could be repeatedly adsorbed and desorbed with GalNAc‐attached poly(HPMA‐GMA) beads. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009