Simple and selective extraction of quercetin with microextraction in packed syringe method using modified glass powder by a molecularly imprinted polymer followed by spectrophotometric determination.

A new sample preparation method based on microextraction in packed syringe was developed for preconcentration of quercetin prior to its spectrophotometric determination. Molecularly imprinted polymers as packing material was used for higher extraction efficiency. First, glass powder as support material because of low cost and available substrate was modified, and then molecularly imprinted polymers were synthesized by the sol-gel method using 3-aminopropyltriethoxysilane as a functional monomer and tetraethyl orthosilicate as cross-linker agent.

Preconcentration of Pb(II) by Magnetic Metal-Organic Frameworks and Analysis Using Graphite Furnace Atomic Absorption Spectroscopy.

In this study, a magnetic metal-organic framework (MOF) was synthesized based on magnetic FeO, Cu(II), and benzene-1,3,5-tricarboxylic acid (Cu-BTC) as a sorbent for solid phase extraction (SPE) of trace amounts of Pb(II) in water and lettuce samples. Pb(II) ion was adsorbed on the magnetic MOF and easily separated by a magnet; therefore, no filtration or centrifugation was necessary. The analyte ions were eluted by HCl 0.

Indirect determination of mercury(II) by using magnetic nanoparticles, CdS quantum dots and mercury(II)-binding aptamers, and quantitation of released CdS by graphite furnace AAS.

This work describes an aptamer based method for highly sensitive determination of Hg(II). A Hg(II)-binding ssDNA aptamer was linked to silica-coated magnetic nanoparticles (magNPs). Then, a conjugate composed of graphene and CdS quantum dots (Gr-CdS) was linked to the complementary ssDNA.