Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 4 de 4
Filter
Add more filters










Database
Language
Publication year range
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 71(1): 31-8, 2008 Nov 01.
Article in English | MEDLINE | ID: mdl-18280774

ABSTRACT

Leaves of bhringaraj and guduchi herb of Kadapa district of Andhra Pradesh, India, are dried and powdered. ICP-MS analysis of samples indicates that copper is present in both the samples. An EPR study of guduchi sample also confirms the presence of Fe(III) whereas Eclipta alba confirms the presence of Fe(III), Mn(II) and Cu(II). Optical absorption spectrum of guduchi indicates that Cu(II) is present in rhombically distorted octahedral environment. NIR and IR results are due to carbonate fundamentals.


Subject(s)
Electron Spin Resonance Spectroscopy/methods , Iron/analysis , Mass Spectrometry/methods , Plant Extracts/analysis , Plants, Medicinal/metabolism , Spectrophotometry, Infrared/methods , Copper/analysis , Manganese/analysis , Optics and Photonics , Plant Extracts/chemistry , Spectrophotometry/methods , Spectroscopy, Near-Infrared/methods , Temperature , Trace Elements
3.
Article in English | MEDLINE | ID: mdl-17428726

ABSTRACT

The behaviour of transition metal ions in beaverite mineral has been studied by spectroscopic techniques such as electron paramagnetic resonance and absorption spectroscopy in the UV-vis and NIR regions. The ground state of Cu(II) ion in beaverite is confirmed as (2)B(1g) since g(parallel)>g(perpendicular) (2.42>2.097). A resonance noticed at g=2.017 is ascribed to Fe(III) impurity. Two sets of three characteristic bands observed in the optical absorption spectra are assigned to the same transitions, (2)B(1g)-->(2)A(1g), (2)B(1g)-->(2)B(2) and (2)B(1g)-->(2)E(g) of Cu(II) ion in tetragonal field. The presence of Fe(III) bands is supportive evidence for iron impurity in the mineral. Mid infrared spectrum is due to overtones and combination tones of water and hydroxyl groups.


Subject(s)
Copper/chemistry , Minerals/chemistry , Optics and Photonics , Electron Spin Resonance Spectroscopy , Spectrophotometry, Ultraviolet , Spectroscopy, Near-Infrared , Temperature , Thermodynamics
4.
Article in English | MEDLINE | ID: mdl-17324611

ABSTRACT

A chalcocite mineral sample of Shaha, Congo is used in the present study. An electron paramagnetic resonance (EPR) study on powdered sample confirms the presence of Mn(II), Fe(III) and Cu(II). Optical absorption spectrum indicates that Fe(III) impurity is present in octahedral structure whereas Cu(II) is present in rhombically distorted octahedral environment. Mid-infrared results are due to water and sulphate fundamentals.


Subject(s)
Electron Spin Resonance Spectroscopy , Minerals/chemistry , Optics and Photonics , Copper , Spectrophotometry, Ultraviolet , Spectroscopy, Near-Infrared , Temperature , Thermodynamics
SELECTION OF CITATIONS
SEARCH DETAIL
...