Transition metal(II) ions with dinegative tetradentate schiff base

Some new coordination polymers of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II), obtained from the interaction of metal acetate with dipotassium salt of N,N’-di(carboxyethylidene)terephthalaldehydediimine (K₂SB) are described. The products, which have been characterized by elemental analyses, magnetic measurements, thermogravimetric analyses, electronic and infrared spectral studies, have composition, [M(SB)(H₂O)₂]_n. These colored coordination polymers are non-hygroscopic and quite stable at room temperature. On the basis of analytical data and IR studies, a 1:1 metal to ligand stoichiometry has been suggested to these coordination polymers. The IR studies have also revealed that ligands are coordinated to metal ion through carboxy oxygen and azomethine nitrogen. All the studies suggested tetradentate nature of the ligand with octahedral symmetry of the coordination polymers. All the coordination polymers are insoluble in acetone, ethanol, chloroform, methanol, benzene, DMF and DMSO. The thermal decomposition of the coordination polymers is studied and indicates that not only the coordinated water is lost but also that the decomposition of the ligand from the coordination polymers is necessary to interpret the successive mass loss.     

Radiochemical separation of bismuth activities using Dalzin,and its application to geological problems

A radiochemical method has been devised for the separation of bismuth activities of the natural series,viz.²¹⁴Bi,²¹⁰Bi and²¹²Bi, and applied to the indirect estimation of their corresponding precursors,²²²Rn,²¹⁰Pb and²¹²Pb, in a wide variety of geological materials. The method consists of the solvent extraction of bismuth in radiochemically pure form from the sample solution atpH 2 with diallyldithiocarbamido-hydrazine (Dalzin) in chloroform, and back extraction with 2M acid. The advantages of this method over the dithizone extraction system are discussed.     

Polymeric Coordination Compounds Derived from Transition Metal(II) with Tetradentate Schiff‐base: Synthetic,Spectroscopic, Magnetic and Thermal Approach

The polymeric coordination compounds have been synthesized using the dipotassium salt of N,N′‐di(carboxymethylene)terephthalaldehydediimine (K₂SB¹) or N,N′‐di(carboxyethylene)terephthalaldehydediimine (K₂SB²) with manganese(II), cobalt(II), nickel(II), copper(II), zinc(II), and cadmium(II). The ligands have been characterized by ¹H‐NMR, and ¹³C‐NMR spectra. The polychelates have been characterized by elemental analyses, magnetic measurements, thermogravimetric analyses, electronic spectra and infrared spectra. The coordination compounds are colored, and the central metal ions are octahedrally coordinated with two water molecules and the Schiff bases. The Schiff bases act as di‐negative tetradentate ligands, in which bonding occurs through two oxygen and two nitrogen atoms. The polymers are insoluble in all common organic solvents such as acetone, methanol, ethanol, N,N‐dimethylformamide and dimethylsulfoxide.     

A new method for sealing containers with liquid samples for radioactivity measurements

It is imperative to use a leak-proof container for counting liquid sample to prevent contamination of costly gamma detectors. We report in this technical note a sealant that ensures no leak. It is a vinyl adhesive sealant used for household purposes, marketed by Gloucester Co., Inc, Franklin, MA under the trade name of Phenoseal (translucent variety). This sealant was superior to other sealants studied because it cures quickly, peels off easily after counting, and contains no detectable radioactivity. We have thoroughly tested this sealant in our laboratory and successfully employed it in the routine analysis of environmental liquid samples.     

Growth and characterization of L‐alanine doped KDP crystals

Potassium Dihydrogen Phosphate (KDP) is an excellent inorganic nonlinear optical (NLO) material with different device applications. Most of amino acids possess NLO property; therefore, it is of interest to dope them in KDP crystals. In the present study, amino acid L‐alanine doped KDP crystals were grown by slow aqueous solvent evaporation technique. The doping of L‐alanine was confirmed by the paper chromatography, the CHN analysis and the FT‐IR spectroscopy. The powder XRD was carried out to assess the single phase nature of the samples. The effect of doping on thermal stability of the crystals was studied by TGA and the kinetic and thermodynamic parameters of dehydration were evaluated. As the amount of doping increased the thermal stability of crystals decreased. However, the second harmonic generation (SHG) efficiency and the UV‐Vis spectroscopy studies indicated that as the L‐alanine doping increased the SHG efficiency and optical transmission percentage increased. The dielectric behavior of the samples has been studied. The variation of dielectric constant, dielectric loss (tanδ), a.c.resistivity and a.c.conductivity with frequency of applied field in the range from 100 Hz to 100 kHz was studied. The dielectric constant and dielectric loss decreased with increase the value of frequency of applied field. The dielectric constant and the dielectric loss values of L‐alanine doped KDP crystals were lower than the pure KDP crystals. The results are discussed. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Quantification of Dopamine in Portulaca oleracea Linn,by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive and accurate high-performance thin-layer chromatographic method has been developed, validated, and used for...     

LC–MS–MS Method for Simultaneous Analysis of Abacavir and Lamivudine in Human Plasma, and Its Application to a Bioequivalence Study

A rapid and sensitive LC–MS–MS method has been developed and validated for simultaneous analysis of abacavir (ABA) and lamivudine (LAM) in human plasma. The analytes were extracted from human plasma by SPE. Nelfinavir (NEL) and emtricitabine (EMT) were used as the internal standards for ABA and LAM, respectively. An RP18 column enabled chromatographic separation of the analytes. The method involves simple isocratic chromatography and MS detection in positive-ionization mode. Validation of the method showed response was a linear function of concentration in the ranges 100.0–7000.0 ng mL^?1 for ABA and 80.0–5000.0 ng mL^?1 for LAM. At the LOQ levels, inter-run and intra-run precision were within 5.80 and 3.51%, respectively, for ABA and within 4.68 and 3.16%, respectively, for LAM. Overall recovery for ABA and LAM was 59.32 and 105.18%, respectively. Total elution time was 2 min only, which enabled quantification of more than 200 plasma samples per day. This validated method was used successfully for analysis of plasma samples from a bioequivalence study.