Laser induced fluorescence magnetic resonance

Laser Stark Spectroscopy Laser Magnetic Resonance Laser Induced Fluorescence Double Resonance Spectroscopy... 

Laser-induced fluorescence (LIF) has also been utilized as a highly sensitive detection principle for CE [48-51]. However, while the LIF detector is now able to achieve zeptomole (10 21) detection limits, conventional derivatization techniques are inefficient at these exceptional levels [52]. Also, CE has successfully been coupled with mass spectrometry (MS) [53], nuclear magnetic resonance (NMR) [54, 55], near-infrared fluorescence (NIRF) [56, 57], radiometric [58], flame photometric [59], absorption imaging [60], and electrochemical (conductivity, amperometric, and potentiometry) [61-63] detectors. A general overview of the main detection methods is shown is Table 1 [64]. 

Experimental Techniques A absorption CIMS = chemical ionization mass spectroscopy CK = competitive kinetics DF discharge flow EPR = electron paramagnetic resonance FP = flash photolysis FT = flow tube FTIR Fourier transform intra-red GC = gas chromatography, UF = laser induced fluorescence LMR = laser magnetic resonance MS = mass spectroscopy PLP = pulsed laser photolysis SC = smog chamber SP = steady (continuous) photolysis UVF = ultraviolet flourescence spectroscopy... 

In this section, some case studies will be presented on the characterization of CMP pad and slurry [17-20] using such advanced analytical techniques as dynamic mechanical analysis (DMA), modulated differential scanning calorimetry (MDSC), thermal gravimetric analysis (TGA), thermal mechanical analysis (TMA), dynamic rheometry, dual emission laser induced fluorescence (DELIF), and the dynamic nuclear magnetic resonance (DNMR). More specifically, these techniques were used to characterize (a) the effect of heat... 

The main sources of data are microwave, inlfared and laser induced fluorescence spectroscopy and their related Doppler-free techniques. Results from magnetic and electric resonance methods are also considered. 

This chapter is concerned with the following techniques in molecular laser spectroscopy (i) laser-Stark spectroscopy and electric field spectroscopy (ii) laser-Zeeman, or laser-magnetic-resonance spectroscopy (LMR) (iii) dispersed laser-induced fluorescence and (iv) double resonance spectroscopy. 

AES, atomic emission spectrometry AP(C)I, atmospheric pressure (chemical) ionization CGC, capillary gas chromatography DAD, diode array detection ESI, electrospray ionization FI, fluorescence detection ICP, indcutively coupled plasma LIE, laser-induced fluorescence Nl, negative ion NMR, nuclear magnetic resonance PFPD, pulsed flame photometric detector SRM, selected reaction monitoring. 

Figure 10.16 shows a block diagram of the whole apparatus, used by PEN-SELIN and his group for atomic beam magnetic resonance spectroscopy detected by laser-induced fluorescence [10.27e]. The pump laser beam crosses the atomic beam several times to assure high pumping efficiency. The rf tran-... 

The study of bimolecular gas reaction rate coefficients has been one of the primary subjects of kinetics investigations over the last 20 years. Largely as a result of improved reaction systems (static flash photolysis systems, flow reactors, and shock tubes) and sensitive detection methods for atoms and free radicals (atomic and molecular resonance spectrometry, electron paramagnetic resonance and mass spectrometry, laser-induced fluorescence, and laser magnetic resonance), improvements in both the quality and the quantity of kinetic data have been made. Summarizing accounts of our present knowledge of the rate coefficients for reactions important in combustion chemistry are given in Chapters 5 and 6. 

Time-resolved laser flash ESR spectroscopy generates radicals with nonequilibrium spin populations and causes spectra with unusual signal directions and intensities. The signals may show absorption, emission, or both and be enhanced as much as 100-fold. Deviations from Boltzmann intensities, first noted in 1963, are known as chemically induced dynamic electron polarization (CIDEP). Because the splitting pattern of the intermediate remains unaffected, the CIDEP enhancement facilitates the detection of short-lived radicals. A related technique, fluorescence detected magnetic resonance (FDMR) offers improved time resolution and its sensitivity exceeds that of ESR. The FDMR experiment probes short-lived radical ion pairs, which form reaction products in electronically excited states that decay radiatively. ... 

The dependence of the dissociation constant kj) and the recombination constants kjt in the reaction (a) on the optical polarization of the atoms A was predicted by Bernheim [65] and Kastler [225] and later demonstrated experimentally [7, 363]. The dependence can be understood from the obvious fact that only hydrogen-like atoms with opposite electronic spins may recombine and form a molecule A2(X1E+). Hence we have kR = kft(l — S2), where S is the degree of electron spin polarization of the atoms. A convenient indicator of dimer formation is provided by the kinetics of the laser-induced molecular fluorescence after switching on magnetic resonance which destroys the polarization of the atoms, as performed by Huber and Weber [201] for a Na — Na2 mixture. The se-... 

Figure 1.13 Selected analytical techniques used for metallomics studies. ICP-OES, inductively coupled plasma optical emission spectroscopy, ICP-MS, inductively coupled plasma mass spectrometry LA-ICP-MS, laser ablation ICP-MS XRF, X-ray fluorescence spectroscopy PIXE, proton induced X-ray emission NAA, neutron activation analysis SIMS, secondary ion mass spectroscopy GE, gel electrophoresis LC, liquid chromatography GC, gas chromatography MS, mass spectrometry, which includes MALDI-TOF-MS, matrix-assisted laser desorption/ ionization time of flight mass spectrometry and ESI-MS, electron spray ionization mass spectrometry NMR, nuclear magnetic resonance PX, protein crystallography XAS, X-ray absorption spectroscopy NS, neutron scattering.

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