Solid-phase Extraction Sorbent For Determination Research Articles

Application potential of dummy molecularly imprinted polymers as solid-phase extraction sorbents for determination of low-mass polybrominated diphenyl ethers in soil and sediment samples

Despite the introduction of restrictive regulations in the USA and the European Union, polybrominated diphenyl ethers (PBDEs) are still found in various types of environmental and biological samples at significant concentration levels. The presence of these persistent organic pollutants in the environment raises important issues because of their negative impact on immunological and neurological systems, and on the hormonal balances in living organisms. From the analytical point of view, the final determination of PBDEs would entail substantial challenges, because it would necessitate conducting the pre-concentration of analytes, or sample clean up. The aim of the present study is to demonstrate the analytical application potential of developed dummy molecularly imprinted polymers as solid-phase extraction sorbents for the selective recognition of low-mass PBDEs. The 4,4′-dihydroxydiphenyl ether was employed as a dummy template of low-mass PBDEs. The developed types of the sorption materials were used in the sample preparation stage of the analytical procedure to determine the PBDE-47 and PBDE-99 levels in selected representatives of environmental samples—reference materials of soil and bottom sediments. The recovery values of PBDE-47 and PBDE-99 from the studied solid samples ranged from 60% to 87%, depending on the applied DMIPs type.

Quartz-Wool-Supported Surface Dummy Molecularly Imprinted Silica as a Novel Solid-Phase Extraction Sorbent for Determination of Bisphenol A in Water Samples and Orange Juice

A type of quartz wool-supported surface dummy molecularly imprinted silica (QW@MIP) was prepared using bisphenol AF as the template molecule for solid-phase extraction of bisphenol A (BPA). The QW@MIP was characterized by FT-IR spectroscopy, scanning electron microscopy, and thermo-gravimetric analysis. The adsorption tests showed that the QW@MIP had high-adsorption ability and a fast binding kinetics for BPA. When used as a solid-phase extraction (SPE) sorbent for BPA, the QW@MIP showed ease of packing SPE cartridge, low flow resistance, high extraction efficiency, high enrichment factor, and good reusability. Moreover, the dummy-imprinting technique used herein can effectively avoid the interference of residual template molecules in sorbent to determination of BPA. A new SPE method was developed using the QW@MIP sorbent, and then coupled with a high-performance liquid chromatography method, it was successfully applied to the detection of BPA spiked in water samples and orange juice and that in a certified sample with recoveries of 96.7–103.1% (RSD = 1.0–2.8%), 96.9–99.9% (RSD = 1.0–2.9%), and 99.2% (RSD = 0.5%), respectively. The limit of detection (S/N = 3) and limit of quantification (S/N = 10) for all samples were 0.05 and 0.17 ng mL−1, respectively. The QW@MIP can be potentially used as a good SPE sorbent for BPA in environmental water samples and beverages.

Polypyrrole as an Efficient Solid-Phase Extraction Sorbent for Determination of Chloramphenicol Residue in Chicken Liver, Kidney, and Meat

A novel, sensitive, inexpensive, and efficient method for the extraction and pre-concentration of chloramphenicol residue in chicken tissues has been developed. In this work, polypyrrole polymer was synthesized and used as an efficient sorbent for solid-phase extraction. Several parameters such as type of salt, salting out effect, pH of extraction solution, temperature, and desorption solvent were optimized. The samples were analyzed by high performance liquid chromatography coupled to photodiode array detection. Under optimized extraction and cleanup conditions (namely, Britton–Robinson buffer 0.1 M adjusted to pH 2.0 with NaCl at 35 °C and using of methanol as desorption solvent), the method showed good linearity and sensitivity. Recovery was in the range of 86.0–93.4, 80.8–89.5, and 77.5–85.6 % for meat, kidney, and liver, respectively. Relative standard deviation was lower than 10 % in all cases indicating that the method can be used as a validated method. The limit of detection and limit of quantitation of the proposed method at various matrices were found to be in the range of 0.1–1 and 0.3–3 ng/g, respectively. These results suggested that the solid-phase extraction base on polypyrrole might be a potential candidate for the extraction of chloramphenicol from chicken tissues.

Graphene nanoplatelets as a highly efficient solid-phase extraction sorbent for determination of phthalate esters in aqueous solution

Graphene nanoplatelet (GN) as a solid-phase extraction (SPE) sorbent in combination with high performance liquid chromatography has been used for the determination of five phthalate esters (PAEs) in aqueous solution. The operation parameters affecting the extraction efficiency were optimized. Comparative studies showed that GN was superior to other common SPE sorbents in terms of recovery and adsorption capacity. Under optimization conditions, detection limits of 0.09-0.33 ng mL(-1) were achieved for five PAEs and enrichment factors of 402-711 for the analytes were obtained. The proposed method was successfully applied for the determination of PAEs in tap water and drink samples with recoveries ranging from 87.7% to 100.9%.

Aptamer-targeted magnetic nanospheres as a solid-phase extraction sorbent for determination of ochratoxin A in food samples

A sorbent based on the aptamer for ochratoxin A was immobilized onto magnetic nanospheres (MNS) and used to develop a magnetic solid-phase extraction procedure to clean up food samples in conjunction with high-performance liquid chromatography separation and fluorescence detection. Specific retention of ochratoxin A by the sorbent was demonstrated, and the capacity of the MNS–aptamer sorbent was determined. The efficacy of this new approach was successfully evaluated through comparison with solid-phase extraction on commercial C18 cartridge. Several different food samples fortified in the range of with 2.5–50 μg/kg yielded mean recoveries from 67% to 90%, respectively. Finally, this oligosorbent was applied to the selective extraction of ochratoxin A from unfortified food samples.