Embedment of Ag(I)-organic frameworks into silica gels for microextraction of polybrominated diphenyl ethers in soils.

Three Ag(I)-organic frameworks, [Ag5(pydc)2(CN)]n, {[Ag4(pydc)2]CH3CN}n, and [Ag(4,4'-bpy)NO3]n, were synthesized and embedded into silica gels to form metal-organic-framework (MOF)-embedded gels for the microextraction of polybrominated diphenyl ethers (PBDEs) in soils. Despite the great differences in the structures of the organic ligands, all three Ag(I)-organic frameworks were found to effectively accumulate and concentrate PBDEs from sample solutions prepared with contaminated soil and purified water, indicating the important roles of Ag centers in PBDE extraction. Under the optimal experimental conditions (MOF mass, water volume, temperature, extraction time, and back-extraction time) for PBDE extraction from sample solutions, the detection limits of seven PBDEs (BDE-28, 47, 99, 100, 153, 154, and 183) ranged from 0.

Separations of substituted benzenes and polycyclic aromatic hydrocarbons using normal- and reverse-phase high performance liquid chromatography with UiO-66 as the stationary phase.

Metal-organic frameworks (MOFs) have great potential for applications in chromatography due to their highly tailorable porous structures and unique properties. In this work, the stable MOF UiO-66 was evaluated as both a normal-phase (NP-) and a reverse-phase (RP-) stationary phase in the high performance liquid chromatography (HPLC) to separate substituted benzenes (SBs) and polycyclic aromatic hydrocarbons (PAHs). It was found that the mobile phase composition has a significant effect on the HPLC separation.

[Human health risk-based environmental criteria for soil: a comparative study between countries and implication for China].

Since the 1990s, most developed countries have issued the risk-based environmental standards or criteria for soil, as well as corresponding technical background documents, this provides methodological references for developing soil environmental standards and criteria in developing countries. However, because of the variability in legislation frameworks, derivation procedures of criteria, environmental conditions and climates, soil types, and habits and customs among countries, there are great differences in the names, roles and values of soil standards and criteria. This paper presents the scientific basis and fundamental features of soil environmental criteria.

The protection of polysaccharide from the Brown Seaweed Sargassum graminifolium against ethylene glycol-induced mitochondrial damage.

The aim of the present study is to evaluate the protective effect of polysaccharide from the Brown Seaweed Sargassum graminifolium (SGP) on ethylene glycol-induced kidney damage and the mechanism of SGP-mediated protection. Mitochondrial lipid peroxidation, mitochondrial swelling, the activity of succinate dehydrogenase (SDH), ATPases and mitochondrial antioxidant enzymes was observed in hyperoxaluric rats. Administration of SGP (25, 100 and 400 mg·kg-1, intragastrically) increased the activities of antioxidant enzymes, SDH and Na+/K+-ATPases, Ca2+-ATPases, Mg2+-ATPases, also decreased mitochondrial lipid peroxidation and mitochondrial swelling.

The use of copper(II) isonicotinate-based micro-solid-phase extraction for the analysis of polybrominated diphenyl ethers in soils.

A micro-solid-phase extraction (μ-SPE) device was developed by filling copper(II) isonicotinate coordination polymer (Cu(4-C(5)H(4)N-COO)(2)(H(2)O)(4)) into a porous polypropylene envelope, and the μ-SPE, coupling with gas chromatography (GC) with a micro-cell electron capture detector (μ-ECD), was used for extraction and determination of PBDEs in soils. Variables affecting extraction procedures, including temperature, water volume, extraction time, and desorption time, were investigated in a spiked soil, and the parameters were optimized. Under the optimal experimental conditions, the method detection limits for seven PBDEs (BDE-28, 47, 99, 100, 153, 154, and 183) were in the range of 0.

Application of portable gas chromatography-photo ionization detector combined with headspace sampling for field analysis of benzene, toluene, ethylbenzene, and xylene in soils.

A method based on headspace (HS) sampling coupling with portable gas chromatography (GC) with photo ionization detector (PID) was developed for rapid determination of benzene, toluene, ethylbenzene, and xylenes (BTEX) in soils. Optimal conditions for HS gas sampling procedure were determined, and the influence of soil organic matter on the recovery of BTEX from soil was investigated using five representative Chinese soils. The results showed that the HS-portable-GC-PID method could be effectively operated at ambient temperature, and the addition of 15 ml of saturated NaCl solution in a 40-ml sampling vial and 60 s of shaking time for sample solution were optimum for the HS gas sampling procedure.

Antioxidant properties of polysaccharide from the brown seaweed Sargassum graminifolium (Turn.), and its effects on calcium oxalate crystallization.

We investigated the effects of polysaccharides from the brown seaweed Sargassum graminifolium (Turn.) (SGP) on calcium oxalate crystallization, and determined its antioxidant activities. To examine the effects of SGP on calcium oxalate crystallization, we monitored nucleation and aggregation of calcium oxalate monohydrate crystals, using trisodium citrate as a positive control.

Bis[μ-4-methyl-2-(2-pyridyl-methyl-sulfan-yl)pyrimidine-κN]bis-[(trifluoro-methanesulfonato-κO)silver(I)].

In the centrosymmetric dinuclear title complex, [Ag(2)(CF(3)SO(3))(2)(C(11)H(11)N(3)S)(2)], the Ag(I) atom is coordinated by two N atoms from two 4-methyl-2-(2-pyridyl-methyl-sulfan-yl)pyrimidine ligands and one O atom from a trifluoro-methane-sulfonate anion in a distorted T-type coordination geometry. The ligand adopts a bidentate bridging coordination mode through one pyridyl N atom and one pyrimidine N atom. In the crystal structure, π-π inter-actions are present between adjacent pyrimidine rings, with a centroid-to-centroid distance of 3.

Tetra-μ-acetato-bis-[(pyridine N-oxide)copper(II)](Cu-Cu).

The mol-ecule of the title binuclear copper(II) complex, [Cu(2)(CH(3)COO)(4)(C(5)H(5)NO)(2)], occupies a special position on a crystallographic inversion centre; the coordination environment of the Cu(II) atom is slightly distorted square-pyramidal and is made up of four O atoms belonging to four acetate groups in the basal plane with the O atom of pyridine N-oxide ligand in the apical position. The Cu-Cu distance is 2.6376 (6) Å.

Bis(5,6-dicarboxy-benzimidazolium) sulfate monohydrate.

In the title compound, 2C(9)H(7)N(2)O(4) (+)·SO(4) (2-)·H(2)O, the sulfate S atom and the water O atom reside on a crystallographic twofold axis. In the crystal, the component species are linked by N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonds, forming a three-dimensional network structure. An intramol-ecular O-H⋯O link is seen in the cation.

2,2'-[o-Phenylenebis(methylenethio)]bis(pyridine N-oxide).

In the title compound, C(18)H(16)N(2)O(2)S(2), the benzene ring makes dihedral angles of 7.41 and 86.59° with the two outer pyridine N-oxygen rings.

A one-dimensional cadmium(II) complex supported by a sulfur-nitro-gen mixed-donor ligand.

In the title compound, catena-poly[cadmium(II)-bis-(μ-5-am-ino-1,3,4-thia-diazole-2-thiol-ato)-κ(2)N(3):S(2);κ(2)S(2):N(3)], [Cd(C(2)H(2)N(3)S(2))(2)](n), the Cd(II) ion is coordinated by two N atoms of the 1,3,4-thia-diazole rings from two ligands and two S atoms of sulfhydryl from two other ligands in a slightly distorted tetra-hedral geometry. The ligands bridge Cd(II) ions, forming one-dimensional chains along [001], which are connected by N-H⋯N and N-H⋯S hydrogen bonds into a three-dimensional network.

Tetra-aqua-bis(3-carboxyl-atopyridine N-oxide-κO)cadmium(II).

In the title complex, [Cd(C(6)H(4)NO(3))(2)(H(2)O)(4)], the Cd(II) atom is situated on a crystallographic centre of inversion. The Cd(II) atom shows a slightly distorted octa-hedral geometry and is coordinated by four O atoms from water mol-ecules and two O atoms from deprotonated carboxyl groups of nicotinic acid N-oxide ligands. The mononuclear complex mol-ecules are linked by O-H⋯O hydrogen bonds, forming a three-dimensional network structure.

2,2'-[Ethane-1,2-diylbis(sulfanedi-yl)]bis-(pyridine N-oxide).

The tile compound, C(12)H(12)N(2)O(2)S(2), lies on an inversion center. The two pyridyl rings are parallel to each other. The structure is devoid of any classical hydrogen bonds due to lack of appropriate donors and acceptors for such bonds.

Tetra-aqua-hexa-kis(μ(2)-quinoline-4-carboxyl-ato)diyttrium(III) dihydrate.

In the title centrosymmetric binuclear complex, [Y(2)(C(10)H(6)NO(2))(6)(H(2)O)(4)]·2H(2)O, each Y(III) atom is nine-coordin-ated by nine O atoms from five ligands and two water mol-ecules in a slightly distorted monocapped square-anti-prismatic coordination environment. The Y(III) atoms are separated by a distance of 4.0363 (9) Å.

Penta-aqua-(1H-benzimidazole-5,6-di-carboxyl-ato-κN)copper(II) penta-hydrate.

The title compound, [Cu(C(9)H(4)N(2)O(4))(H(2)O)(5)]·5H(2)O, contains one crystallographically independent Cu(II) atom and one 1H-benzimidazole-5,6-dicarboxyl-ate (bdc) ligand, along with five coordinated and five uncoordinated water mol-ecules. The Cu(II) atom is six-coordinated by one N atom from the bdc ligand and five O atoms from water mol-ecules, giving an octa-hedral coordination geometry. Hydrogen bonds link the mononuclear complex and uncoordinated water mol-ecules into a three-dimensional network.

catena-Poly[silver(I)-μ-pyrazolato-κN:N'].

The title compound, [Ag(C(3)H(3)N(2))](n), has an infinite helical chain structure in which each pyrazolate group bridges two Ag(I) atoms related by a 2(1) axis with an intra-chain Ag⋯Ag separation of 3.3718 (7) Å. Each Ag(I) center is linearly coordinated by two N atoms [N-Ag-N angle = 169.