Huading Liang

On-line solid phase extraction coupled to flame atomic absorption spectrometry for the determination of trace copper and zinc in environmental and biological samples

In this work, bamboo charcoal (BC) was used as a sorbent for on-line solid phase extraction (SPE) coupling with flame atomic absorption spectrometry (AAS) for trace copper and zinc determination in environmental and biological samples. Under the optimum pH of 5.5 (for Zn) and 7.0 (for Cu), trace copper and zinc were effectively adsorbed on the microcolumn and the retained cations were efficiently eluted with HCl or HNO3 with an appropriate concentration and flow rate for on-line AAS determination. With a sample loading time of 60 s at a sample flow rate of 7.6 mL min−1, the enhancement factors of 39 (for Cu) and 30 (for Zn) and detection limits (3σ) of 0.60 µg L−1 (for Cu) and 0.36 µg L−1 (for Zn), respectively, were achieved. The sample throughput was 45 h−1. At the level of 20 µg L−1of Cu(II) and Zn(II), the precision (RSD, n = 11) were found to be 0.26% and 1.6%, respectively. The proposed method has been successfully applied to the determination of copper and zinc in environmental and biological samples.

Synthesis, crystal structure, and DNA-binding of a 3-D netlike supramolecular manganese picrate complex with 2,6-bis(benzimidazol-2-yl)pyridine

Manganese picrate with 2,6-bis(benzimidazol-2-yl)pyridine (L) has been prepared and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. The complex crystallizes in the triclinic system, space group P–1 with a = 14.234(3) Å, b = 14.324(2) Å, c = 15.242(2) Å, α = 77.569(2)°, β = 63.350(3)°, γ = 82.130(2)°, and Z = 2. Interaction of the complex with calf-thymus DNA (CT-DNA) has been investigated with diverse spectroscopic techniques and viscosity measurements, and the binding constant is 1.76 × 105 mol−1. Results suggest that the complex bind to CT-DNA via intercalation.

Facile synthesis of Ag@Fe3O4@C-Au core-shell microspheres for surface-enhanced Raman scattering

In this paper, a facile approach has been developed to synthesize the novel multifunctional Ag@Fe3O4@C-Au magnetic core-shell microspheres that display a highly efficient surface-enhanced Raman scattering (SERS) substrate with high stability and reproducibility. The morphology, size, chemical component, and magnetic property of as-prepared composite microspheres were characterized by scanning transmission electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectra (XPS), and vibrating sample magnetomerter (VSM), respectively. The enhancement effect on the Raman active was investigated by using rhodamine-b (RdB) as a probe molecule. The result shows that the well-designed Ag@Fe3O4@C-Au core-shell microspheres have uniform sphere size and high magnetization, and the SERS signals of RdB on the Ag@Fe3O4@C-Au microspheres were much stronger than those on both Ag@Fe3O4 and Fe3O4@C-Au microspheres.

Highly efficient and porous TiO2-coated Ag@Fe3O4@C-Au microspheres for degradation of organic pollutants

In this paper, we reported a novel hierarchical porous Ag@Fe3O4@C-Au@TiO2 core@shell microspheres with a highly photocatalytic activity and magnetically separable properties. The synthesis method is included of a Fe3O4 magnetic embedded Ag core (Ag@Fe3O4), an interlayer of carbon modified by PEI to form sufficient amounts of amine functional groups (Ag@Fe3O4@C-PEI), the grafting of Au nanoparticles on the surface of Ag@Fe3O4@C-PEI (Ag@Fe3O4@C-Au), and an ordered porous TiO2 structured shell. As an example of the applications, the photocatalytic activities of the samples were investigated by the reduction of Rhodamine B (RhB) under visible-light irradiation. The results show that the porous Ag@Fe3O4@C-Au@TiO2 core@shell microspheres display higher adsorption and photocatalytic activities compared to the pure porous TiO2 and Ag@Fe3O4@C@TiO2 microspheres, which are attributed to the local surface plasmon resonance (LSPR) by the Ag and Au nanoparticles and the high specific surface area.

Preparation and luminescent properties of a terbium complex incorporated into the pores of mesoporous silica MCM-41 by a sol–gel method

A complex of terbium and a new podand-type polyaromatic carboxylic acid [3,6-bis[(4′-carboxyphenoxy)methyl]-1,2,4,5-tetramethylbenzene(H2BCM)] have been synthesized, introduced into the pores of mesoporous silica by the sol–gel method, and characterized by IR, UV-Vis, X-ray diffraction, and inductively coupled plasma atomic emission spectrometry. The Tb complex encapsulated in the pores of mesoporous silica MCM (Mobil composition of matter)-41 (MCM-41-Tb2(BCM)3) displayed characteristic luminescence emission of the pure Tb complex (Tb2(BCM)3); compared with the complex itself, the unit-mass luminescence intensity of the mesoporous silica hybrid material is enhanced four times. The luminescence lifetime of Tb3+ in the hybrid material is also longer than that in pure complex.