Recent Advances in Molecular-Imprinting-Based Solid-Phase Extraction of Antibiotics Residues Coupled With Chromatographic Analysis

Abuse and residues of antibiotics cause great harm to organisms and the environment. Appropriate sample pretreatment is usually required for sensitive determination, because of the low content presence of a variety of antibiotics in complicated matrices. Molecular-imprinting-based solid-phase extraction (MISPE) has been widely used for sample pretreatment of antibiotics, using molecularly imprinted polymers (MIPs) as adsorbents. Herein, we comprehensively review the recent advances of MISPE of antibiotics, followed by chromatographic analysis. Various solid-phase extraction (SPE) modes based on MIPs are briefly introduced, such as conventional SPE, dispersive SPE, magnetic SPE, matrix solid-phase dispersion, and pipette-tip SPE. Then, several emerging preparation techniques for antibiotics MIPs are summarized including surface imprinting, nanoimprinting, living/controlled radical polymerization, multitemplate imprinting, multifunctional monomer imprinting, and dummy template imprinting. Subsequently, applications of MISPE to analysis of a variety of antibiotics residues since 2018 are overviewed, including sulfonamides, quinolones, tetracycline, and others. Finally, the preparation and application of antibiotics MIPs are prospected.

Sample Treatment Methods for the Determination of Phenolic Environmental Estrogens in Foods and Drinking Water

Environmental endocrine-disrupting chemicals (EDCs) are a large category of chemicals that can disrupt normal endocrine functions of organisms. They can enter the environment and foodstuffs in different ways and bring great threat to human health. Phenolic environmental estrogens (PEEs) are the typical representatives of EDCs and include bisphenols, alkylphenols, and others such as dibromophenol, dichlorophenol, 4-nitrophenononylphenol, etc. Even trace amounts of PEEs can cause serious damage to the human reproductive, nervous, and immune systems; therefore, it is very important to develop accurate and sensitive methods for their determination in different matrixes. At the present, there are still many challenges in the determination of PEEs in the samples with complex matrixes, and the sample treatment is one of the key issues. This review deals with the recent advances in sample treatment methods for the analysis of PEEs in foods and drinking water, including improved and newly developed liquid–liquid extraction, solid-phase extraction (SPE), magnetic SPE, matrix solid-phase dispersion with new adsorbent materials, and stir-bar sorptive extraction. In addition, the challenges and perspectives are also briefly discussed.

Simultaneous determination of traces of Pt, Pd, Os, Ir, Rh, Ag and Au metals by magnetic SPE ICP OES and in situ chemical vapour generation

An ICP-OES method for the determination of trace amounts of PGEs plus Au and Ag in environmental samples has been developed.

Three-dimensional graphene/Fe3O4-based magnetic solid phase extraction coupled with high performance liquid chromatography for determination of carvedilol in human blood plasma

3D-graphene–Fe3O4-based magnetic SPE-HPLC for determination of carvedilol.

Magnetic solid-phase extraction combined with in situ slurry cold vapor generation atomic fluorescence spectrometry for preconcentration and determination of ultratrace mercury

A magnetic SPE method combined with CVG-AFS for the determination of Hg2+is established.

Application of Magnetic Nanoparticles to Residue Analysis of Organochlorine Pesticides in Water Samples by GC/MS

This paper describes a novel magnetic-SPE method for the determination of organochlorine pesticides (OCPs) in environmental water samples by use of Fe3O4-magnetic nanoparticles (MNPs) coated with oleic acid followed by GC/MS. The chemisorption of oleic acid onto Fe3O4-MNPs provides reusability of the developed sorbent materials several times. The effects of different parameters such as pH, desorption solvent, contact time, temperature, ionic strength, and sorbent dosage on the efficiency of magnetic-SPE were investigated. The optimized SPE method involved shaking 50 mL of water sample (pH 4) with 50 mg oleic acid coated Fe3O4-MNPs for 1 h, isolating the sorbent with an Nd-Fe-B magnet, and eluting the OCPs with methanol. An ionic strength of 0.1 M and temperature of 15°C provided the maximum extraction efficiency. The LOQs were in the range of 0.006 to 0.048 μg/L. For three fortification levels, recoveries were in the range of 44–108%, with RSD <5%. The developed SPE method was successfully applied to real water samples, and it is viable, rapid, and easy to use for analysis of OCPs in water samples.