In the present work, a new method was established by applying solid-phase extraction (SPE) to preconcentrate and separate polymeric aluminum (Al) and using ICP-AES to determine the polymeric Al, the total monomeric Al, and the total Al in soil extracts, respectively. A modified resin was prepared with impregnated 8-hydroxyquinoline-5-sulfoxinate (HQS) on the anion-exchange resin. It has good recognition ability for Al fractions, compared to the commonly used cation ion-exchange resin, which has a better ability to adsorb cations and a weak ability to recognize detailed Al species. The optimum conditions for Al fractionation sorption, elution and separation and the interference of foreign ions were studied with the prepared resin by continuous column and batch procedures. Monomeric Al was bound to Pyrocathecol Violet (PCV) at pH 6.2, whereas the polymeric Al species did not react with PCV for at least 15 min. Because a stable complex of Al-PCV was not absorbed on the HQS modified resin, the polymeric Al could be preconcentrated on-line by the HQS-modified resin. The adsorbed polymeric Al was eluted with 3 mL of 3 mol L-1 of HCl, and then detected by ICP-AES. The method has been applied to directly determine polymeric Al in soil extracts with high selectivity as well as a high preconcentration factor. It gives a limit of detection of 0.6 ng mL-1 with a relative standard deviation of less than 5.7% (n = 5, 0.24 µg mL-1 Al).

Two new isostructural dinuclear zinc(II) complexes with Schiff base 5-methoxy-2-[(2-methylaminoethylimino)methyl] phenol were prepared and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray diffraction. Both complexes are phenolate O-bridged dinuclear zinc(II) compounds with crystallographic twofold rotation axis symmetry. The Schiff base acts as a tridentate chelating ligand. The Zn atom is five-coordinated in a square pyramidal geometry. The preliminary urease inhibitory activity of both complexes was investigated.

Multi-walled carbon nanotubes (MWCNTs) were decorated with magnetite (Fe3O4) nanoparticles and then used to modify a stainless steel electrode. The Fe3O4/MWCNTs composite was characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and X-ray diffraction patterns. Electrochemical properties of the modified electrode revealed a substantial catalytic activity for the reduction of hydrogen peroxide. The relationship between peak current and the concentration of hydrogen peroxide was linear in the range from 0.06 mmol L−1 to 0.36 mmol L−1, and the lowest detectable concentration is 0.01 mmol·L−1 (S/N = 3). The modified stainless steel electrode displays excellent stability.

The purifying effect of the eco-ditch technology system, which combined with ＂aquatic plants（water hyacinth, Eichhornia crassipes ）-microbes （Bacillus subtilis ）-aquatic animals （snail, Margarya）＂, on the effluent from greenhouse-culture of Chinese soft-shelled turtle（Pelodiscus sinensis） was studied. Change of each main nutrient pollutant indicators of the treated water sample was analyzed continuously for several months. The results showed that： Total nitrogen（TN） concentration of the treated water decreased 75 %, ammonia nitrogen（NH[ -N） concen- tration decreased 91 %, total phosphorus（TP） concentration decreased 83%, chemical oxygen demand （CODe,） decreased 62 %, dissolved oxygen（DO） content in water increased nearly four times, and the water pH main- tained at a neutral level, by utilizing the eco-ditch technology system to purify the effluent from the green- house-culture for nearly five months. During the experiment period, the treated water also gradually changed from initial yellow or brown turbidity into a slightly yellowish turbidity, and no odor. It could be seen that, the purifying effect of using eco-ditch technology system, which combined with ＂aquatic plants-microbes- aquatic animals＂, to remediate the effluent from greenhouse-culture of Chinese soft-shelled turtle was very significant, thus, it could be concluded that the eeo-ditch technology system had good prospects of promotion and application in effluents purification of other fresh water fish culture.

反刍动物的瘤胃微生物能以非蛋白氮(NPN)为氮源合成自身蛋白质,其中,尿素因其具有来源广、成本低、含氮量高等优点,目前已成为世界范围内畜牧业生产中广泛使用的NPN饲料,但直接饲喂尿素适口性差,又会在瘤胃脲酶的催化下爆发式释放出水溶性的NH3,极易导致动物NH3中毒和粪便中大量NH3的排放,污染环境;脲酶抑制剂可以调控尿素NPN饲料的降解速度,显著提高反刍动物利用尿素的效率,提高动物生产性能。作者对近10年来国内外NPN饲料的种类、提高反刍动物NPN利用的缓/控释技术、对尿素NPN饲料氮代谢的调控机理等进行了综述。

The title oxidovanadium(V) complex, [V(C(15)H(11)N(3)O(5))(CH(3)O)O], was obtained by the reaction of 2-hy-droxy-3-meth-oxy-benzaldehyde, 4-nitro-benzohydrazide and vanadyl sulfate in methanol. The V(V) atom is five-coordinated by the two O and one N donor atoms of the Schiff base ligand, one methano-late O atom and one oxido O atom, forming a distorted square-pyramidal geometry.

The title oxidovanadium(V) complex, [V(C(17)H(16)N(2)O(3))(CH(3)O)O], was obtained by the reaction of 3-eth-oxy-2-hy-droxy-benzaldehyde, 4-methyl-benzohydrazide and vanadyl sulfate in methanol. The V(V) atom is coordinated by the O,N,O'-tridentate Schiff base ligand, one methano-late O atom and one oxide O atom, forming a distorted VO(4)N square-pyramidal coordination geometry. The oxide O atom lies at the apex of the square pyramid and the N atom of the ligand and the methano-late O atom are trans. The dihedral angle between the benzene rings of the ligand is 1.8 (3)°.

The complete mol-ecule of the title mononuclear zinc(II) complex, [Zn(NCS)(2)(C(13)H(13)N(3))], is generated by crystallographic twofold symmetry, with the metal atom lying on the rotation axis. The pendant methyl group of the ligand is statistically disordered over two sites. The Zn(2+) cation is coordinated by the N,N',N''-tridentate Schiff base ligand, and by two thio-cyanate N atoms, forming a distorted ZnN(5) trigonal-bipyramidal geometry.

The title oxidovanadium(V) complex, [V(C15H11N3O5)(CH3O)O], was obtained by the reaction of 2-hy­droxy-3-meth­oxy­benzaldehyde, 4-nitro­benzohydrazide and vanadyl sulfate in methanol. The VV atom is five-coordinated by the two O and one N donor atoms of the Schiff base ligand, one methano­late O atom and one oxido O atom, forming a distorted square-pyramidal geometry.

The complete molecule of the title mononuclear zinc(II) complex, [Zn(NCS)(2)(C13H13N3)], is generated by crystallographic twofold symmetry, with the metal atom lying on the rotation axis. The pendant methyl group of the ligand is statistically disordered over two sites. The Zn2+ cation is coordinated by the N,N',N ''-tridentate Schiff base ligand, and by two thiocyanate N atoms, forming a distorted ZnN5 trigonal-bipyramidal geometry.

A new Schiff base zinc(II) complex with the formula 2[Zn(C(12)H(18)N(2)O(2))(2)(NCS)]center dot[Zn(NCS)(4)] was prepared and structurally characterized by elemental analysis, IR spectrum, and single crystal X-ray diffraction. The compound consists of two mononuclear [Zn(C(12)H(18)N(2)O(2))(2)(NCS)] complex cations, in which the Zn atom is in a trigonal-bipyramidal geometry, and one [Zn(NCS)(4)] complex anion, in which the Zn atom is in a tetrahedral geometry.

The title oxovanadium(V) complex, [V(C18H13N3O2)(CH3O)-O(CH3OH)], was obtained by the reaction of 1-(2-hydroxynaphthalen-1-yl)ethanone, nicotinohydrazide and vanadyl sulfate in methanol. The V V atom is six-coordinated by the N,N,O-tridentate Schiff base ligand, one methanolate O atom, one methanol O atom and one oxide O atom, forming a distorted octahedral geometry. The methanol O atom lies trans to the V=O group. The dihedral angle between the pyridine ring and the naphthalene ring system is 31.52 (10)degrees. In the crystal, inversion dimers linked by pairs of O-H center dot center dot center dot N hydrogen bonds occur.

Urease inhibitors can inhibit the decomposition rate of urea, and decrease the air pollution caused by ammonia. In this paper, three new copper(II) and nickel(II) complexes [Cu 2 L 2 (μ 1,1 -N 3 ) 2 ] ( 1 ), [Cu(HL) 2 ]Br 2 ( 2 ), and [Ni 3 L 2 (DMF) 2 (μ 2 –η 1 :η 1 -CH 3 COO) 2 (μ 1,1 -N 3 ) 2 ] ( 3 ), where L = 5-bromo-2-(((2-isopropylamino) ethyl)imino)methyl)phenolate, HL = 5-bromo-2-(((2-isopropylammonio)ethyl)imino)methyl)phenolate are synthesized and characterized. The complexes are characterized by elemental analyses, IR, UV-Vis spectra, molar conductivity, and single crystal X-ray diffraction. The X-ray analysis indicates that Cu atoms in complexes 1 and 2 are in square pyramidal and square planar coordination, respectively. The Ni atoms in complex 3 are in octahedral coordination. The molecules of the complexes are linked through hydrogen bonds and π⋯π interactions. The inhibitory effects of the complexes on jack bean urease are studied, which show that the copper complexes have a strong inhibitory effect on urease.

The mononuclear zinc title complex, [Zn(C(20)H(22)N(2)O(4))(H(2)O)], was obtained by the reaction of 3-eth-oxy-salicyl-aldehyde, ethane-1,2-diamine, and zinc acetate in methanol. The Zn atom is five-coordinated by two phenolate O and two imine N atoms of the tetradentate Schiff base ligand and by one water O atom, forming a square-pyramidal geometry. In the crystal, pairs of mol-ecules are linked via inter-molecular O-H⋯O hydrogen bonds, forming dimers.

The complete molecule of the title mononuclear zinc(II) complex, [Zn(NCS)2(C13H13N3)], is generated by crystallographic twofold symmetry, with the metal atom lying on the rotation axis. The pendant methyl group of the ligand is statistically disordered over two sites. The Zn2+ cation is coordinated by the N,N′,N′′-tridentate Schiff base ligand, and by two thiocyanate N atoms, forming a distorted ZnN5 trigonal–bipyramidal geometry.

The title mononuclear zinc complex, [ZnCl(2)(C(17)H(26)N(2)O(2))], was obtained by the reaction of 2-hy-droxy-4-meth-oxy-benzaldehyde, N-cyclo-hexyl-propane-1,3-diamine and zinc chloride in methanol. The Zn(II) atom is four-coordinated by the phenolate O atom and imine N atom of the bidentate zwitterionic Schiff base ligand 2-{[3-(cyclo-hexyl-amino)-prop-yl]imino-meth-yl}-5-meth-oxy-phenol, and by two chloride ions, generating a distorted ZnONCl(2) tetra-hedral geometry. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, forming chains along the c-axis direction.

The mononuclear zinc title complex, [Zn(C20H22N2O4)(H2O)], was obtained by the reaction of 3-ethoxysalicylaldehyde, ethane-1,2-diamine, and zinc acetate in methanol. The Zn atom is five-coordinated by two phenolate O and two imine N atoms of the tetradentate Schiff base ligand and by one water O atom, forming a square-pyramidal geometry. In the crystal, pairs of molecules are linked via intermolecular O—H...O hydrogen bonds, forming dimers.

The title mononuclear cobalt(III) complex, [Co(C(14)H(19)N(2)O(2))(C(8)H(7)O(2))(NCS)], was obtained by the reaction of 2-acetyl-phenol, 2-(morpholin-4-yl)ethyl-amine, ammonium thio-cyan-ate and cobalt nitrate in methanol. The Co(III) atom is coordinated by one phenolate O, one imine N, and one amine N atom of the tridentate Schiff base ligand, two O atoms of the 2-acetyl-phenolate anion and one thio-cyanate N atom. This results in a fairly regular fac-CoN(3)O(3) octa-hedral coordination geometry for the metal ion. The dihedral angle between the two benzene rings is 88.3 (3)°.

The title oxovanadium(V) complex, [V(C18H13N3O2)(CH3O)O(CH3OH)], was obtained by the reaction of 1-(2-hydroxynaphthalen-1-yl)ethanone, nicotinohydrazide and vanadyl sulfate in methanol. The VV atom is six-coordinated by the N,N,O-tridentate Schiff base ligand, one methanolate O atom, one methanol O atom and one oxide O atom, forming a distorted octahedral geometry. The methanol O atom lies trans to the V=O group. The dihedral angle between the pyridine ring and the naphthalene ring system is 31.52 (10)°. In the crystal, inversion dimers linked by pairs of O—H...N hydrogen bonds occur.