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  • Author or Editor: J. H. Patil x
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Abstract

The growth of neodymium tartrate crystals was achieved in silica gel by single diffusion method. Optimum conditions were established for the growth of good quality crystals. Fourier transform infrared (FT-IR) spectroscopic study indicates the presence of water molecules and tartrate ligands and suggests that tartrate ions are doubly ionised. The thermal behaviour of the material was studied using thermogravimetry (TG), differential thermal analysis (DTA), derivative thermogravimetry (DTG) and differential scanning calorimetry (DSC). Thermogravimetric analysis support the suggested chemical formula of the grown crystal to be Nd2(C4H4O6)3·7H2O, and the presence of seven water molecules as water of hydration. It is shown that the material is thermally stable up 45 °C beyond which it decomposes through many stages till the formation of neodymium oxide (Nd2O3) at 995 °C. The decomposition pattern is reported to be typical of a hydrated metal tartrate.

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Abstract

In this study, calcium cadmium tartrate single crystals were grown in silica gel at ambient temperature. Effects of various parameters like gel pH, gel aging, gel density, and concentration of reactants on the growth of these crystals were studied. Crystals having different morphologies and habits were obtained. Transparent, diamond-like pyramidal-shaped crystals of calcium cadmium tartrate were obtained. Some of the crystals obtained were faint yellowish, with some milky white crystals being attched to them due to fast growth rate; faces are well developed and polished. The grown crystals were characterized by thermoanalytic techniques (TG, DTA, and DTG), and powder X-ray diffraction (XRD). The crystal system is confirmed to be orthorhombic having lattice parameters a = 7.9411 Å, b = 7.0396 Å, and c = 6.7271 Å as determined by powder XRD analysis. TG, DTA, and DTG analyses show a remarkable thermal stability. The results of these observations are described and discussed.

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Summary

A simple, sensitive, and accurate liquid chromatographic method with photodiode array detector was developed for the determination of andrographolide, phyllanthin, and hypophyllanthin. The separation was carried out on a reverse-phase 250 mm × 4.6 mm, 5μ symmetry C8 column (Waters). The gradient was prepared from 0.1% orthophosphoric acid (solvent A) and (1:1) acetonitrile:methanol (solvent B) as mobile phase delivered at a flow rate of 1 mL min−1. A linear behavior was observed between observed peak area response, and concentration of analytes was investigated, with good correlation coefficient. The method established was successfully applied to quantify andrographolide, phyllanthin, and hypophyllanthin from the herbal hepatoprotective formulation.

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Summary

This paper describes a new, simple, precise, and accurate HPTLC method for quantification of (−)-epicatechin in the leaves of Cassia fistula. The leaves were separately extracted with methanol and water by both maceration and hot extraction (Soxhlet apparatus). Chromatographic separation of the drug was performed on aluminium foil silica gel 60 F254 plates with toluene-ethyl acetate-formic acid-methanol 20:12:4:4 (v/v) as mobile phase. Densitometric evaluation of the separated zone was performed at 280 nm. Epicatechin in the extract was satisfactorily resolved with R F 0.22 ± 0.02. The accuracy and reliability of the method were assessed by evaluation of linearity (200–800 ng per band), precision (method precision RSD 1.42% and instrumental precision RSD 1.12%), accuracy (98.12%), and specificity in accordance with ICH guidelines.

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