Quadropole

Cole, M. Enke, C. Direct determination of phospholipid structures in microorganisms by fast atom bombardment triple quadropole mass spectrometry. Anal. Chem. 1991, 63,1032-1038. 

Figure 9.3 Schematic diagram of a multicollector ICP-MS (MC-ICP-MS). This is a double focusing instrument, with a hexapole (a six-rodded version of the quadropole) and a 90° magnetic selector, and a multiple bank of ion detectors, allowing simultaneous measurement of a number of isotopic ratios.

Douglas DJ, French JB (1992) Collisional focusing effects in radio frequency quadropoles. J Am Soc Mass Spectrom 3 398-407... 

FTICR, Fourier transform ion cyclotron resonance QTOF, quadropole time-of-flight TOF, time-of-flight. 

Mossbauer spectroscopy also provides structural information.97-100 In particular it is possible to deduce from peak asymmetry the separate appearance of surface atoms as size is decreased they cause an increase in intensity of quadrupole splitting, and two quadropole components indicate two kinds of surface atoms.97 Au1 and Au111 species are also sometimes recognised,99 and sometimes not.98... 

HPLC column was directed into a triple quadropole mass spectrometer equipped with an atmospheric pressure articulated ion spray (electrospray) source. Using MS-MS conditions, dissociation of the parent ions yielded daughter ions comparable to the IM+H]+ of PAF and other molecules, such as O-phosphocholine. Quantitative analyses were obtained by selective ion monitoring. Amounts as low as 0.3 ng of PAF and similar compounds were detected. Interestingly with the lyso derivatives, the limited of detection was 3 ng. The primary alkyl chain lengths present in the neutrophil-derived PAF were 16 0 and 18 0. No mention was made of the presence of any 1-0-long chain acyl analogs. 

Modem mass spectrometers provide a powerful tool for the indentification and study of nonmetal fluorides and their derivatives. Many compounds are sufficiently volatile to make sampling relatively easy. In highly fluorinated compounds, the 100% natural abundance of F simplifies interpretation of many spectra and high-resolution spectra are often not required for unambiguous interpretation of mass spectra. Numerous nomnetal fluorides and derivatives were first identified by mass spectrometry and subsequently obtained in sufficient amounts to characterize by other methods. Modem quadropole mass spectrometers are particularly useful in the analysis of fluorine compounds and their open architecture facilitates the analysis of highly reactive fluorine compounds and compounds of low thermal stability. 

Boyd, R.K., Tandem mass spectrometry quadropole and hybrid instruments, Metftodi nzymo/. 193, 154-200, 1990 Jonscher, K.R. and Yates, J.R., 111, The quadrupole ion trap mass spectrometry — a small solution to a big challenge. Anal. Biochem. 244, 1-15, 1997 Chemushevich, I.V., Loboda, A.V., and Thomson, B.A., An introduction to quadrupole-time-of-flight mass spectrometry, J. Mass Spectrom. 36, 849-865, 2001 Ens, W. and Standing, K.G., Hybrid quadrapole/time-of-flight mass spectrometers for analysis of biomolecules. Methods Enzymol. 402,49-78, 2005 Payne, A.H. and GUsh, G.L., Tandem mass spectrometry in quadrupole ion trap and ion cyclotron resonance mass spectrometers. Methods Enzymol. 402, 109-148, 2005. 

Z is the atomic number, a and h arc the radii of an ellipsoid of revolution along the axis of symmetry and perpendicular to it, respectively, f is the mean radius, Ar = a - h, and Ar/r is a measure of the deformation. Q may be positive a > h) or negative a < h). Nuclides with 7 = 0 or i do not have an electrical quadropole momentum that means their nuclei have spherical symmetry. 

Since the shape of the cavity is that of overlapping spheres, an alternative, natural strategy could be to expand the potential V 7) in harmonics i.e., potentials from monopoles, dipoles, quadropoles,. . . ). Also here various strategies have been proposed. - ... 

Separate the formed ions according to their mass-to-charge ratio (m/z ratio). This takes place in the mass analyzer. By far, the most used analyzer is the quadropole, either as single or as triple quadropole, combined with a soft ioniza-... 

Fig. 1 Schematic representation of a mass spectrometer depicting its main components and the different modes used. Abbreviations DIP direct insertion probe DEP direct exposure probe GC gas chromatography LC liquid chromatography CE capillary chromatography TEC thin-layer chromatography FEE field-flow fractionation APCI atmospheric pressure ionization El electron impact Cl chemical ionization FAB fast-atom bombardment PD plasma desorption MALDI matrix-assisted laser desorption ionization ED laser desorption TSP thermospray ESI electron spray ionization HSI hypherthermal surface ionization Q quadropole QQQ triple quadropole TOE time-of-fiight FTMS Fourier transform mass spectrometer IT ion trap EM electrom multiplier PM photomultiplier ICR ion cyclotron resonance.

O.C.Kistner, A.W.Sunvar, Evidence for Quadropole Interaction of Fc and Influence of Chemical Binding on Nuclear Gamma Ray Energy, Phys.Rcvi it, 4 (1960)412-415,... 

Zinc is of interest to a range of practical applications from electroceramics to metallo-proteins, for which Zn NMR studies could potentially provide valuable information. However, Zn NMR suffers from the various problems associated with its low natural abundance and low magnetic moment, in addition to its nuclear quadropole interaction which presents linewidth problems for samples containing Zn in a non-cubic environment. Consequently, the number of reported Zn studies of solids is limited. The primary reference for Zn NMR is a dilute aqueous Zn solution, but cubic ZnSe would make a useful solid secondary reference material since its MAS linewidth is only 16 Hz (Wu 1998). 

Quadropol-Kernresonanz-Untersuchungen (s. Kap. 10.3) beweisen, daB die negative Ladung in alien XY2"-Verbindungen in Ubereinstimmung mit den Resonanzformeln auf die auBeren Atome verteilt ist. 

The extracts are analysed using a Finnigm 9610 gas chromatograph interfaced to a Finnigan 4023 quadropole mass spectrometer and a Super Incos, NOVA 4xdata system with a 70 MB disc drive. Mass spectra is recorded with 1 scan per 0,6 sec in full scan mode (35-400 amu). The mass spectrometer is operated in the electron impact mode at 70e V. The analysis is performed using a 30m DB-5 fused silica capillary colunm with 0,25 pm film thickness (J W Scientific, Inc.). The iigector temperature is kept at 270°C, the interface oven at 250°C and the ion source at 270°C. The oven is initially held at 30°C for 5 mm and increased 4°C per minute to 300°C and kept there for 10 minutes. 

The CO-TPD measurements were performed in a flow reactor, described elsewhere [12]. A quadropole mass spectrometer continuously analysed the gas composition after the monolith... 

The similarity between the Mossbauer parameters of ferritin and a synthetic polymer derived from hydrolysed ferric nitrate have been pointed out previously (101) the polymer has a similar room temperature Mossbauer spectrum with isomer shift and quadropole splitting of 0.48 and 0.67 mm/sec. respectively. At very low temperatures the spectrum of the polymer is also closely similar to ferritin. 

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