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1.
Appl Spectrosc ; 67(11): 1275-84, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24160879

ABSTRACT

Laser-induced breakdown spectroscopy (LIBS) has been evaluated for the determination of uranium in real-world samples such as uraninite. NIST Standard Reference Materials were used to evaluate the spectral interferences on detection of uranium. The study addresses the detection limit of LIBS for several uranium lines and their relationship to non-uranium lines, with emphasis on spectral interferences. The data are discussed in the context of optimizing the choice of emission lines for both qualitative and quantitative analyses from a complex spectrum of uranium in the presence of other elements. Temporally resolved spectral emission intensities, line width, and line shifts were characterized to demonstrate the parameter influence on these measurements. The measured uranium line width demonstrates that LIBS acquired with moderately high spectral resolution (e.g., by a 1.25 m spectrometer with a 2400 grooves/mm grating) can be utilized for isotope shift measurements in air at atmospheric pressure with single to tens of parts per million (ppm) level detection limits, as long as an appropriate transition is chosen for analysis.

2.
Article in English | MEDLINE | ID: mdl-18722805

ABSTRACT

Infrared spectroscopic studies of 1:1 and 1:2 complexes of lead(II) bromide and lead(II) iodide with 1,10-phenanthroline were reported. Vibrational assignments are made by comparison to reported spectra of the uncomplexed 1,10-phenanthroline molecule. Small shifts of the ligand vibrational bands are characteristic of the complexes.


Subject(s)
Lead/chemistry , Phenanthrolines/chemistry , Bromides/chemistry , Bromides/radiation effects , Halogens/chemistry , Halogens/radiation effects , Iodides/chemistry , Iodides/radiation effects , Lead/radiation effects , Light , Models, Biological , Phenanthrolines/radiation effects , Photochemistry , Spectrophotometry, Infrared , X-Ray Diffraction
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 66(4-5): 1361-3, 2007 Apr.
Article in English | MEDLINE | ID: mdl-16872880

ABSTRACT

Solid-state 207Pb NMR studies have been conducted on mixed lead(II) halides of the type PbFX, where X=Cl, Br, or I. NMR data for the mixed halides are compared to the solid-state NMR data for the divalent, binary lead halides, PbX2 (X=F, Cl, Br, I). The NMR data are evaluated in the context of the structures of the compounds and the effects of the mixed halides on the electronic structure of the divalent lead. Data sets for the mixed halides are discussed and compared to those for the regular lead(II) halides.


Subject(s)
Fluorides/chemistry , Lead/chemistry , Crystallography, X-Ray , Isotopes , Magnetic Resonance Spectroscopy
4.
Analyst ; 131(11): 1207-9, 2006 Nov.
Article in English | MEDLINE | ID: mdl-17066187

ABSTRACT

We demonstrate a multi-spectrum technique for facile, quantitative determination of lead in solid materials using solid-state (207)Pb NMR that avoids the major problem of uniform excitation across a wide spectral range; the method can be employed without chemical separation or other chemical manipulations and without any prior sample preparation, resulting in a non-destructive analysis, and producing results that are in agreement with gravimetric analyses of mixed samples of the lead halides.


Subject(s)
Lead/analysis , Fluorides/chemistry , Iodides/chemistry , Isotopes , Lead/chemistry , Magnetic Resonance Spectroscopy/methods
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