X-ray excited optical

Several instmmental methods are available for quantitative estimation of from moderate to trace amounts of cerium in other materials. X-ray fluorescence is widely available, versatile, and suitable for deterrninations of Ce, and any other Ln, at percent levels and lower in minerals and purer materials. The uv-excited visible luminescence of cerium is characteristic and can be used to estimate Ce content, at ppm levels, in a nonluminescing host. X-ray excited optical luminescence (15), a technique especially appropriate for Ln elements including cerium, rehes on emissions in the visible, and also measures ppm values. Atomic emission spectrometry is appHcable to most lanthanides, including Ce (16). The precise lines used for quantitative measurement must be chosen with care, but once set-up the technique is suitable for routine analyses. 

Spectroscopic properties of [Ru(bpy)3] " ", and the effects of varying the diimine ligands in [Ru(bpy)3 L ] + (L = diimine) on the electronic spectra and redox properties of these complexes have been reviewed. The properties of the optical emission and excitation spectra of [Ru(bpy)3] +, [Ru(bpy)2(bpy-d )] + and [Ru(bpy-d )3] " " and of related Os, Rh , and Pt and Os species have been analyzed and trends arising from changes in the metal d or MLCT character in the lowest triplet states have been discussed. A study of the interligand electron transfer and transition state dynamics in [Ru(bpy)3] " " has been carried out. The results of X-ray excited optical luminescence and XANES studies on a fine powder film of [Ru(bpy)3][C104]2 show that C and Ru localized excitation enhances the photoluminescence yield, but that of N does not. 

E. A.R D Silva and V.A. Fassel, X-ray excited optical luminescence of the rare earths 441... 

C. R.J. Conzemius, Analysis of rare earth matrices by spark source mass spectrometry 377 37D. E.L. DeKalb and V.A. Eassel, Optical atomic emission and absorption methods 405 37E. A.P. D Silva and V.A. Eassel, X-ray excited optical luminescence of the rare earths 441 37E. E.W.V. Boynton, Neutron activation analysis 457... 

A number of less commonly used analytical techniques are available for determining PAHs. These include synchronous luminescence spectroscopy (SLS), resonant (R)/nonresonant (NR)-synchronous scan luminescence (SSL) spectrometry, room temperature phosphorescence (RTP), ultraviolet-resonance Raman spectroscopy (UV-RRS), x-ray excited optical luminescence spectroscopy (XEOL), laser-induced molecular fluorescence (LIMP), supersonic jet/laser induced fluorescence (SSJ/LIF), low- temperature fluorescence spectroscopy (LTFS), high-resolution low-temperature spectrofluorometry, low-temperature molecular luminescence spectrometry (LT-MLS), and supersonic jet spectroscopy/capillary supercritical fluid chromatography (SJS/SFC) Asher 1984 Garrigues and Ewald 1987 Goates et al. 1989 Jones et al. 1988 Lai et al. 1990 Lamotte et al. 1985 Lin et al. 1991 Popl et al. 1975 Richardson and Ando 1977 Saber et al. 1991 Vo-Dinh et al. 1984 Vo- Dinh and Abbott 1984 Vo-Dinh 1981 Woo et al. 1980). More recent methods for the determination of PAHs in environmental samples include GC-MS with stable isotope dilution calibration (Bushby et al. 1993), capillary electrophoresis with UV-laser excited fluorescence detection (Nie et al. 1993), and laser desorption laser photoionization time-of-flight mass spectrometry of direct determination of PAH in solid waste matrices (Dale et al. 1993). 

Woo CS, D Silva AP, Passel VA. 1980. Characterization of environmental samples for polynuclear aromatic hydrocarbons by an x-ray excited optical luminescence technique. Anal Chem 52 159-164. 

Soderholm L, Antonio MR, Williams C, Wasserman SR (1999) XANES spectroelectrochemistiy A new method for determining formal potentials. Anal Chem 71 4622-4628 Soderholm L, Liu GK, Antonio MR, Lytle FW (1998) X-ray excited optical luminescence (XEOL) detection of X-ray absorption fine structure (XAFS). J Chem Phys 109 6745-6752. 

Armelao L, Heigl F, Jitrgensen A, Blyth RIR, Regier T, Zhou X-T, Sham TK (2007) X-ray excited optical luminescence studies of ZnO and Eu-doped nanostructures. J Phys Chem C 111 10194-10200... 

Pettifer RF, Glanfield A, Gardelis S, Hamilton B, Dawson P, Smith AD (1995) X-Ray excited optical luminescence (XEOL) study of porous silicon. Phys B Condens Matter 208-209 484-486 Pikulev VB, Kuznetsov SN, Saren AA, Gardin YE, Gurtov VA (2006) Energy transfer under photoexcitation of porous silicon-fullerene nanocomposite in oxygen-containing ambient. 

Hessel CM, Henderson EJ, Kelly JA, Cavell RG, Sham TK, Veinot JCG (2008) Origin of luminescence from silicon nanocrystals a near edge X-ray absorption fine structure (NEXAFS) and X-ray excited optical luminescence(XEOL) study of oxide-embedded and free-standing systems. J Phys ChemC 112 14247-14254... 

Siller L, Krishnamurthy S, Kjeldgaard L, Horrocks BR, Chao Y, Houlton A, Chakraborty AK, Hunt MRC (2009) Core and valence exciton formation in x-ray absorption, x-ray emission and x-ray excited optical luminescence from passivated Si nanocrystals at the Si L2,3 edge. J Phys Condens Matter 21 095005... 

---