Tetra-aqua-bis-(tetra-zolido-κN)magnesium.

In the crystal structure of the title compound, [Mg(CHN(4))(2)(H(2)O)(4)], the Mg(II) atom is six-coordinated by two N atoms from two tetra-zolide anions and four O atoms from four coordinated water mol-ecules in a slightly distorted octa-hedral geometry. The Mg atom is located on centres of inversion whereas the tetra-zolide anion and the water mol-ecules occupy general positions. The crystal packing is stabilized by intermolecular O-H⋯N hydrogen bonding between the tetra-zolide anions and the coordinated water mol-ecules.

Bis(µ-5-carboxyl-atotetra-zolido)bis-[aqua-(2,2'-bipyrid-yl)cadmium(II)].

In the title dinuclear Cd(II) complex, [Cd(2)(C(2)N(4)O(2))(2)(C(10)H(8)N(2))(2)(H(2)O)(2)], each Cd atom is in a slightly distorted octa-hedral coordination by two N atoms and one O atom of two 1H-tetra-zole-5-carboxyl-ate (TZC) ligands, two N atoms of a 2,2'-bipyridyl ligand and one water O atom. The TZC ligand acts in a tridentate N,O-chelating N-bridging mode to two symmetry-equivalent Cd(II) atoms. The complex reveals mol-ecular C(i) symmetry. Extensive O-H⋯O hydrogen bonding plays an important role in the crystal packing.

Diaqua-bis-(3-nitro-benzoato-κO)bis-[1H-5-(3-pyrid-yl)-3-(4-pyrid-yl)-1H-1,2,4-triazole-κN]cobalt(II) dihydrate.

In the centrosymmetric title compound, [Co(C(7)H(4)NO(4))(2)(C(12)H(9)N(5))(2)(H(2)O)(2)]·2H(2)O, the Co(II) atom, located on an inversion center, is coordinated by two N atoms [Co-N = 2.155 (3) Å] and four O atoms [Co-O = 2.099 (2)-2.117 (3) Å] in a distorted octa-hedral geometry. Inter-molecular N-H⋯O, O-H⋯N and O-H⋯O hydrogen bonds link the components into a three-dimensional supramolecular framework.

Tetra-aqua-bis[3-(3-pyrid-yl)-5-(4-pyrid-yl)-1,2,4-triazolido]nickel(II) dihydrate.

In the title compound, [Ni(C(12)H(8)N(5))(2)(H(2)O)(4)]·2H(2)O, the Ni(II) atom is coordinated by the two N atoms [Ni-N = 2.094 (3) Å] and four O atoms [Ni-O = 2.063 (3)-2.083 (2) Å] in a distorted octa-hedral geometry. The mol-ecule is centrosymmetric and the Ni(II) atom is located on an inversion center. Inter-molecular O-H⋯N and O-H⋯O hydrogen bonds link the complex into a three-dimensional supra-molecular framework.

[Resonance scattering spectra of apolipoprotein immunocomplex particles and its analytical application].

In pH 6.8 Na2 HPO4-NaH2PO4 buffer solution and in presence of polyethylene glycol (PEG), apolipoprotein AI (ApoAI) and apolipoprotein B (ApoB) would combine with their corresponding antibody and produced immune complex particles in size of about 180 nm and 140 nm respectively, which exhibit stronger resonance scattering (RS) effect at 340 nm and 470 nm. The influence of pH, antisera volume, PEG concentration, incubation time and co-exists substances was considered. Under the optimal conditions, the RS intensity is proportional to the concentrations of ApoAI and ApoB when their concentration is in the range of 8.4-430.0 ng x mL(-1) and 14.8-590.0 ng x mL(-1), respectively. The detection limits (DL) are 6.2 ng x mL(-1) for ApoAI and 7.0 ng x mL(-1) for ApoB. The method was successfully applied to determination of ApoAI and ApoB in human serum samples, with satisfactory results.

[Immune resonance scattering spectral method for the determination of trace IgG].

In pH 7.0 Tris-HCl buffer solution, goat-anti-rabbit IgG is combined with rabbit IgG specifically, and aggregates to form immune complex particles that exhibit three resonance scattering peaks at 330, 400 and 520 nm respectively, and a synchronous scattering peak at 470 nm, in the presence of PEG-20000. The scattering intensity at 470 nm is linear to the rabbit IgG concentration in the range of 1.33 to 133.3 microg x mL(-1). The detection limit is 0.99 microg x mL(-1). The method was applied to the quantitative analysis of rabbit IgG, with satisfactory results.

[Spectrophotometric determination of chondroitin sulfate with victory blue B].

In pH 4.0 acetic acid-sodium acetate buffer solution, cationic dye victory blue B shows an absorption peak at 614 nm, and the absorption peak decreases after it reacts with chondroitin sulfate to form association particles. The decrease in absorption value is linear with chondroitin sulfate concentration in the range of 0. 1-5 microg x mL(-1), and the correlation efficient is 0.9986. The method was applied to the determination of chondroitin sulfate in synthesis samples and real samples with rapidity, simplicity and good accuracy.

A new immune resonance scattering spectral assay for trace fibrinogen with gold nanoparticle label.

Gold nanoparticles in size of 9.0 nm was prepared by the trisodium citrate and used to label goat anti-human fibrinogen. In the pH 6.2 buffer solution and in the presence of polyethylene glycol (PEG), the immune reaction between gold-labeled goat anti-human fibrinogen and fibrinogen took place and the labeled gold nanoparticles were released from the goat anti-human fibrinogen, and the released gold particles aggregated which leaded the resonance scattering intensity at 560 nm (I560 nm) to enhance greatly. The I560 nm is proportional to the fibrinogen concentration in the range from 0.027 to 1.07 microg mL(-1). The detection limit is 1.14 ng mL(-1). This simple assay was applied to determination of fibrinogen in human plasma, with satisfactory results.

A new and sensitive resonance-scattering method for determination of trace nitrite in water with rhodamine 6G.

In the medium HCl-KI-rhodamine dye, NO(2) (-) reacts with excess I(-) to form I(3) (-) and the I(3) (-) and rhodamine dye combine to form an association particle which gives three resonance-scattering (RS) peaks at 320 nm, 400 nm, and 595 nm. In systems containing rhodamine 6G (Rh6G), rhodamine B (RhB), rhodamine S (RhS), and butyl rhodamine B (BRhB) the resonance scattering intensity at 400 nm is proportional to nitrite concentrations in the range 2.3-276 ng mL(-1), 9.2-184 ng mL(-1), 9.2-184 ng mL(-1), and 9.2-92 ng mL(-1), respectively. Because of the high sensitivity, wide linear range, and good stability of the Rh6G system, it has been used for determination of nitrite in water samples, with satisfactory results. The spectral results have been used to verify that the formation of (Rh6G.I(3))(n) association particles and their interface with the system are main factors that cause the RS enhancement.