Novel Imprinted Polymer for the Preconcentration of Cadmium with Determination by Inductively Coupled Plasma Mass Spectrometry

Abstract

A novel Cd(II)-imprinted polymer was prepared with chemical immobilization approach by using N-methacryloyl-L-histidine as a vinylated chelating agent for on-line solid phase extraction of Cd(II) for determination by inductively coupled plasma mass spectrometry. Cd(II)-monomer complex was synthesized and copolymerized via bulk polymerization method in the presence of ethyleneglycoldimethacrylate cross-linker. The resulting polymer was leached with 1.0 mol L−1 HNO3 to generate the cavities in the polymer for Cd(II) ions. The experimental conditions, including load pH, solution flow rate, and eluent concentration for effective sorption of Cd(II) were optimized using a minicolumn of the imprinted polymer. A volume of 5.0 mL sample 5 μg L−1 Cd(II) solution at pH 6.5 was loaded onto the column at 2.0 mL min−1 by using a sequential injection system (FIALab 3200) followed by elution with 1.0 mL of 0.75 mol L−1 HNO3. The relative selectivity coefficients of the imprinted polymer for Cd(II) were 38.5, 3.5, 3.0, 2.5 and 6.0 in the presence of Cu(II), Ni(II), Zn(II), Co(II) and Pb(II), respectively. Computational calculations revealed that the selectivity of the imprinted polymer was mediated by the stability of Cd(II)-N-methacryloyl-L-histidine complex which was far more stable than those of commonly used monomers, such as 4-vinyl pyridine, methacrylic acid and vinylimidazole. The detection limit (3s) and relative standard deviation (%) were found to be 0.004 μg L−1 and 3.2%, respectively. The method was validated by analysis of seawater certified reference material (CASS-4) and successfully applied to the determination of Cd(II) in coastal seawater and estuarine water samples.

Flow-Through Macroporous Polymer Monoliths Containing Artificial Catalytic Centers Mimicking Chymotrypsin Active Site

“…All sample solutions loaded into the monolithic columns were filtered with the use of MCE or PTFE syringe filters with pore size of 0.22 µm produced by Jet Biofil (Guangzhou, China). The synthesis of MA-His was carried out according to the protocol published elsewhere [41] with some changes. Briefly, 5.00 g of L-histidine (0.032 mol), 0.20 g of sodium nitrite (0.003 mol), and 30 mL of potassium carbonate solution (water/saturated solution of K 2 CO 3 = 95/5 (vol%/vol%)) adjusted to a value of 9.8 (control by a pH meter) with 0.83 g of sodium hydroxide (0.021 mol) were placed into a three-necked flask with a volume of 100 mL.…”

The selective recognition mechanism of a novel highly hydrophobic ion-imprinted polymer towards Cd(ii) and its application in edible vegetable oil

“…It is commonly prepared by imprinting the target ions in a polymer network followed by removing the template ions to give permanent cavities that are complementary to sizes and shapes of the template ions. 12,13 As a derived technique, IIPs have displayed a considerable potential for selective extraction and recovery of the template ions from complicated vegetable oil samples. However, conventional methods of manufacturing IIPs such as bulk and precipitation polymerization can cause many recognition sites that are deeply embedded in the inner material, which results in difficulty in recognizing the target ions and challenges in elution because of the diffusion barrier.…”

Synthesis and Application of Novel Magnetic Ion-Imprinted Polymers for Selective Solid Phase Extraction of Cadmium (II)

“…Therefore, developing reliable methods for the removal and determination of cadmium in food is important. A wide range of analytical techniques to evaluate cadmium(II) in the spiked or real samples have been reported in recent years, including atomic absorption spectrometry (AAS) [ 4 ], inductively coupled plasma mass spectrometry (ICP-MS) [ 5 ], electrochemical sensor [ 6 ]. Among them, atomic absorption spectrometry has been popular because of its simplicity, easy operation, and low cost [ 7 ].…”