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Abstract  

Neutron capture gamma-ray activation analysis technique has been used for the non-destructive analysis of Fe, Cr, Ni, Mn and B in stainless steel and iron ore samples. It has been shown that the use of low energy capture gamma-rays, ranging from 0.2 to 1.4 MeV, helps considerably in reducing the time of analysis. The problem of congestion of peaks due to compton continuum and the double and single escape peaks in this region of the spectrum has been overcome by using a Ge(Li) detector in conjunction with a 15.25 cm thick bifurcated NaI(Tl) annulus in anticompton mode. The results obtained by this technique have been compared with those of the chemical analysis.

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Summary

Ashwaghanda, Withania somnifera, is one of the most widely used herbs in Ayurvedic medicine. Leaves and roots are the traditionally used parts of the plant. An RP-HPLC method using a binary acetonitrile-water gradient containing 0.1% acetic acid has been developed for analysis of withaferin A. The method was validated in accordance with ICH guidelines and used for analysis of the withanolide content of the flowers, leaves, and roots of W. somnifera. The withanolide content was highest in the flowers.

Open access
Journal of Thermal Analysis and Calorimetry
Authors:
Rabia Nazir
,
Muhammad Mazhar
,
Tehmina Wakeel
,
Muhammad J. Akhtar
,
Muhammad Siddique
,
Muhammad Nadeem
,
Nawazish A. Khan
, and
Muhammad R. Shah

Abstract

Pyrolysis of trisbipyridineiron(II) chloride under controlled thermal conditions and inert atmosphere of argon gas yields a residue of iron nanoparticles. Evolved gas analysis by GC–MS and 1H NMR revealed emission of bipyridine, 6-chlorobipyridine, 6,6′-dichlorbipyridine, bipyridine hydrochloride, and hydrochloric acid as decomposition products. CHN, XRPD, EDXRF, TEM, AFM, and 57Fe Mössbauer spectroscopy of the residue indicated formation of pure iron nanoparticles in the size range of 50–72 nm. Based on these results a mechanism for thermal degradation of trisbipyridineiron(II) chloride has been worked out.

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