Determination of fungicides in fruit juice by ultrasound-assisted dispersive liquid-liquid microextraction based on solidification of floating organic solvent droplets followed by high performance liquid chromatography.

Ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) based on solidification of the floating organic solvent droplets (SFO) combined with HPLC was used for determination of five fungicides in fruit juice samples. 1-Dodecanol, which has a low density and low toxicity, was used as the extraction solvent in UA-DLLME. The solidification of floating organic droplets facilitates the transfer of analytes from the aqueous phase to the organic phase. This method was easy, quick, inexpensive, precise, and linear over a wide range. Under the optimized conditions, the enrichment factors for a 5 mL fruit juice sample were 25 to 56, and the LODs for the five fungicides ranged from 5 to 50 microg/L. The average recoveries ranged from 71.8 to 118.2% with RSDs of 0.9 to 13.9%. Application of the DLLME-SFO technique allows successful separation and preconcentration of the fungicides at a low concentration level in fruit juice samples.

Diaqua-bis-(5-carb-oxy-2-propyl-1H-imidazole-4-carboxyl-ato-κN,O)nickel(II) tetra-hydrate.

In the title complex, [Ni(C(8)H(9)N(2)O(4))(2)(H(2)O)(2)]·4H(2)O, the Ni(II) ion is coordinated in a slightly distorted octa-hedral environment formed by two bis-chelating H(2)pimda (H(3)pimda is 2-propyl-1H-4,5-dicarb-oxy-lic acid) ligands and two coordinated water mol-ecules. In the crystal structure, a three-dimensional framework is formed by inter-molecular O-H⋯O and N-H⋯O hydrogen bonds involving the solvent water mol-ecules, coordinated water mol-ecules, carboxyl-ate O atoms and the protonated N atoms of the H(2)pimda ligands. The propyl groups of each H(2)pimda ligand are disordered over two sets of sites with refined occupancies of 0.50 (2):0.50 (2) and 0.762 (11):0.238 (11). In one water solvent mol-ecule, one of the H atoms was refined as disordered over two sites of equal occupancy.

A redetermination of bis-(5,5'-diethyl-barbiturato)bis-(imidazole)cobalt(II).

The title complex, [Co(C(8)H(12)N(2)O(3))(2)(C(3)H(4)N(2))(2)], whose structure was first determined by Wang & Craven [(1971). J. Chem. Soc. D, pp. 290-291], has been redetermined with improved precision. A crystallographic twofold rotation axis passes through the Co atom, which is tetrahedrally coordinated by two N atoms from two barbital ligands and two N atoms from two imidazole ligands. The mol-ecules are self-assembled via inter-molecular N-H⋯O hydrogen-bonding inter-actions into a supra-molecular network.

Poly[[µ(2)-aqua-aqua-(µ(3)-3,5-dinitro-salicylato)barium(II)] monohydrate].

In the title coordination polymer, {[Ba(C(7)H(2)N(2)O(7))(H(2)O)(2)]·H(2)O}(n), the Ba(II) atom is ten-coordinated by seven O atoms from four 3,5-dinitro-salicylatate ligands, two µ(2)-bridging aqua ligands and one water mol-ecule. The coordination mode is best described as a bicapped square-anti-prismatic geometry. The 3,5-dinitrosalicylatate ligands bridge three Ba atoms. Centrosymmetrically related dinuclear barium units, with a Ba⋯Ba separation of 4.767 (5) Å, form infinite chains, which are further self-assembled into a supra-molecular network through inter-molecular O-H⋯O hydrogen-bonding inter-actions between O atoms of 3,5-dinitro-salicylatate ligands and water mol-ecules.

Aqua-bis(1H-imidazole-κN)bis-(4-methyl-benzoato)-κO;κO,O'-nickel(II).

In the mononuclear title compound, [Ni(C(8)H(7)O(2))(2)(C(3)H(4)N(2))(2)(H(2)O)], the Ni(II) atom is coordinated by three carboxylate O atoms (from a bidentate 4-methyl-benzoate ligand and a monodentate 4-methyl-benzoate ligand), two N atoms (from two imidazole ligands) and a water mol-ecule in an octa-hedral geometry. Inter-molecular O-H⋯O hydrogen-bonding inter-actions lead to infinite chains, which are further self-assembled into a supra-molecular network through inter-molecular N-H⋯O hydrogen-bonding inter-actions and π-π stacking [centroid-centroid distance = 3.717 (2) Å].