Synthesis of magnetic molecularly imprinted polymers for the selective separation and determination of metronidazole in cosmetic samples.

In this study, novel magnetic molecularly imprinted polymers (MMIPs) were developed as a sorbent for solid-phase extraction (SPE) and used for the selective separation of metronidazole (MNZ) in cosmetics; MNZ was detected by high-performance liquid chromatography (HPLC). First, magnetic Fe3O4 nanoparticles (NPs) were prepared by the co-precipitation of Fe(2+)and Fe(3+) ions in an ammonia solution; then oleic acid (OA) was modified onto the surface of Fe3O4NPs. Finally, the MMIP was prepared by aqueous suspension polymerization, involving the copolymerization of Fe3O4NPs@OA with MNZ as the template molecule, methacrylic acid (MAA) as the functional monomer, ethylene glycol maleic rosinate acrylate (EGMRA) as the cross-linking agent, and 2,2-azobisisobutyronitrile (AIBN) as the initiator. The MMIP materials showed high selective adsorption capacity and fast binding kinetics for MNZ; the maximum adsorption amount of the MMIP to MNZ was 46.7 mg/g. The assay showed a linear range from 0.1 to 20.0 µg/mL for MNZ with the correlation coefficient 0.999. The relative standard deviations (RSD) of intra- and inter-day ranging from 0.71 to 2.45% and from 1.06 to 5.20% were obtained. The MMIP can be applied to the enrichment and determination of MNZ in cosmetic products with the recoveries of spiked toner, powder, and cream cosmetic samples ranging from 90.6 to 104.2, 84.1 to 91.4, and 90.3 to 100.4%, respectively, and the RSD was <3.54%.

Chloridobis[2-(1,3-thia-zol-4-yl-κN)-1H-benzimidazole-κN(3)]cobalt(II) chloride dihydrate.

In the title compound, [CoCl(C(10)H(7)N(3)S)(2)]Cl·2H(2)O, the Co(II) atom is five-coordinated by four N atoms from two chelating 2-(1,3-thia-zol-4-yl)-1H-benzimidazole ligands and one Cl atom in a distorted trigonal-bipyramidal geometry. In the crystal, N-H⋯O and O-H⋯Cl hydrogen bonds and π-π inter-actions between the thia-zole, imidazole and benzene rings [centroid-to-centroid distances 3.546 (2), 3.683 (2) and 3.714 (2) Å] link the complex cations, chloride anions and uncoordinating water mol-ecules into a three-dimensional network.

4,6-Dichloro-5-(2-meth-oxy-phen-oxy)-2,2'-bipyrimidine.

In the title compound, C(15)H(10)Cl(2)N(4)O(2), the dichloro-pyrimidine and meth-oxy-phen-oxy parts are approximately perpendicular [dihedral angle = 89.9 (9)°]. The dihedral angle between the two pyrimidine rings is 36.3 (4)° In the crystal, there are no hydrogen bonds but the mol-ecules are held together by short inter-molecular C⋯N [3.206 (3) Å] contacts and C-H⋯π inter-actions.

Aqua-bis-(benzoato-κO)(1,10-phenanthroline-κN,N')zinc(II).

The Zn atom in the title compound, [Zn(C(7)H(5)O(2))(2)(C(12)H(8)N(2))(H(2)O)], is five-coordinate in a distorted trigonal-bipyramidal coordination environment involving two O atoms of two monodentate benzoates, two N atoms of a 1,10-phenanthroline mol-ecule and one O atom of a water mol-ecule. The axial positions are occupied by a carboxyl-ate O atom from the benzoate ligand and an N atom from the 1,10-phenanthroline ligand [N-Zn-O = 146.90 (7)°]. The water mol-ecule forms an intra-molecular O-H⋯O hydrogen bond; an inter-molecular O-H⋯O hydrogen bond gives rise to a dimer.

[Spectroscopy characteristics of various aluminum phosphates in Al2O3-P2O5-H2O system and its high temperature products].

Various aluminum phosphates were prepared with phosphoric acid and aluminum hydroxide under different conditions. IR, XRD, Raman and SEM were used to study the structure difference and their change in heating process and particle morphology of obtained products and aluminum tripolyphosphate. The results show that the spectral characteristic change of phosphate from H2PO4-, PO4(3-), H2P3O10(3-) and PO3- can be seen when P/Al molar ratio = 3 or the condensation temperature is different. The PO symmetric stretching peaks shift to lower wavenumber and the bands widen along with the extent of polymerization. After aluminum tripolyphosphate is heated, the frequencies of stretching vibrational modes depend on the micro-structure units of phosphate and increase with the extent of polymerization. Both Raman and infrared spectra can characterize the pattern of the hydroxyl stretching vibrations. The laminated thickness of reaction product is increases and laminar boundary is vague until the clinker clew is formed.