Bone provides an important source of forensic evidence. The storage conditions of bone have been recognised as a factor in
maintaining the integrity of such evidence. Thermogravimetric analysis (TG) has been employed to examine the effects of storage
environments and preparation methods on the structural properties of pig bones. A comparison of oven and freeze drying has
been made to study the effect of storage conditions. A comparison has also been made of ground bone specimens with cut specimens.
Freeze-dried hand ground specimens provided the most consistent results and, thus, this is the recommended method of preparation
of bone specimens for TG analysis.
Authors:A. Birajdar Birajdar, S. Meyyanathan Meyyanathan, R. Raja Raja, N. Krishanaveni, and B. Suresh
An isocratic RP-HPLC method has been developed and validated for simultaneous analysis of ambroxol hydrochloride (AMB) with cetirizine hydrochloride (CTZ) and of ambroxol hydrochloride (AMB) with levo-cetirizine dihydrochloride (LCTZ) in combined solid dosage forms. Formulations containing AMB with CTZ (tablets) and AMB with LCTZ (capsules) are used as antihistaminic H1 blockers. Chromatography was performed on a 250 mm × 4.6 mm, 5-μm particle size, C18 (ODS) column with a 45:30:30 (v/v) mixture of 30 mM aqueous ammonium sulphate (pH 5.5), acetonitrile, and methanol as mobile phase at a flow rate of 1 mL min−1. The detection wavelength was 230 nm and analysis was performed at room temperature. Hydrochlorothiazide was used as internal standard for both formulations. Plots of drug-to-internal standard peakarea ratios (response factor) against respective concentrations were linear in the range 3 to 20 μg mL−1 for AMB and in the range 1 to 11 μg mL−1 for CTZ and LCTZ. The method was precise (RSD < 2) and accurate for analysis of both drugs in pharmaceutical dosage forms. Statistical data and results from recovery studies were reported for both formulations.
Authors:P. Govindan, A. Palamalai, K. Vijayan, M. Raja, S. Parthasarathy, S. Mohan, and R. Rao
A two step precipitation using ammonium carbonate and oxalic acid as the precipitants for thorium and iron is developed for the purification of 233U. Ammonium carbonate is added to the feed to increase the pH of the solution. The effect of pH on the solubility of U, Th and Fe in an excess of ammonium carbonate is studied. This indicates that the solubility of Th and Fe is minimum at pH 7 and the recovery of uranium is maximum. The effect of the concentration of thorium and iron on the recovery of uranium at pH 7 is studied. This indicates that the ammonium carbonate precipitation tolerates 2 g/l of thorium and 10 g/l of iron keeping losses of uranium to a minimum. If the feed solution contains more than a tolerable concentration of thorium the precipitation is followed in two steps: (1) Bulk of the thorium is removed by oxalate precipitation, (2) the remaining thorium and iron in the supernatant are removed by ammonium carbonate precipitation. A flow sheet is proposed for the purification of 233U from thorium and iron present in a strip product concentrate obtained during the reprocessing of irradiated thorium rods.
Authors:S. Raja, P. Thomas, B. Stuart, J. Guerbois, and C. O’Brien
An accurate means of determining bone age is a goal for forensic scientists. In this study, thermogravimetric analysis (TGA)
has been used to examine pig bone specimens of different post-mortem age. Analysis of bone in both air and nitrogen atmospheres
reveals a decrease in total mass loss as the bones age. Two mass loss steps due to the decomposition of the organic bone components
were observed and show decreasing trends with age for decomposition in an air atmosphere. In a nitrogen atmosphere the decomposition
was observed to be more complex and age dependence of the mass loss for each step was not identified. The TGA data, however,
demonstrates the potential of the technique as a means of estimating post-mortem age of forensic bone specimens.