Spectrometry particle beam

R. M. Marce, H. Prosen, C. Crespo, M. Calull, R Boirull and U. A. Th Brinkman, Online ti ace enrichment of polar pesticides in environmental waters by reversed-phase liquid cliromatography-diode array detection-particle beam mass spectrometry , J. Chromatogr. 696 63-74 (1995). 

C. Aguilar, R Bomtll and R. M. Marce, Determination of pesticides by on-line trace enrichment-reversed-phase liquid cliromatogr aphy-diode-array detection and confirmation by particle-beam mass spectrometry , Chromatographia 43 592-598 (1996). 

Solka, B. H., Particle beam LC-MS spectra of anionic surfactants , in Proceedings of the 40th ASMS Conference on Mass Spectrometry and Allied Topics, Washington, DC, May 31-June 5, 1992, pp. 1464-1465. 

Table 5.7 Theoretically predicted polypeptides from the trypsin digestion of S-lacto-globulin (/3LG) . Reprinted from J. Chromatogr., A, 763, Turula, V. E., Bishop, R. T., Ricker, R. D. and de Haseth, J. A., Complete structure elucidation of a globular protein by particle beam liquid chromatography-Fourier transform infrared spectrometry and electrospray liquid chromatography-mass spectrometry - Sequence and conformation of /3-lactoglobulin , 91-103, Copyright (1997), with permission from Elsevier Science...

See footnote cto Table3 LC/PB/MS = hquid chromatography/particle beam mass spectrometry LC/APcl/ESl-MS/MS = liquid chromtography/atmospheric pressure chemical ionization/electrospray ionization tandem mass spectrometry LC/FTIR = Fourier transform infrared LC/TSP-MS/MS = liquid chromatography/thermospray tandem mass spectrometry LC/TSP-MS = liquid chromatography/thermospray mass spectrometry. 

The use of the particle-beam interface for introduction of samples into a mass spectrometer (PB-MS), without chromatographic separation, was shown by Bonilla [55] to be a useful method for analysis of semi-volatile and nonvolatile additives in PC and PC/PBT blends. The method uses the full power of mass spectrometry to identify multiple additives in a single matrix. The usefulness, speed and simplicity of this approach were illustrated for AOs, UVAs, FRs, slip agents and other additives. 

Figure 7.28 Typical particle-beam interface. After Ashcroft [524]. From A.E. Ashcroft, Ionization Methods of Organic Mass Spectrometry, The Royal Society of Chemistry, Cambridge (1997). Reproduced by permission of The Royal Society of Chemistry...

Rutherford backscattering spectrometry (RBS) which analyses the elastic scattering of the particle beam from the target nuclei. Most RBS analyses use less than 2.2 MeV He++ beams. 

R.D. Voyksner, C.S. Smith and P.C. Knox, Optimization and application of particle beam high-performance liquid chromatography/mass spectrometry to compounds of pharmaceutical interest, Biomed. Environ. Mass Spectrom., 19 (1990) 523-534. 

T.A. Bellar, T.D. Behymer and W.L. Budde, Investigation of enhanced ion abundances from a carrier process in high-performance liquid chromatography particle beam mass spectrometry, J. Am. Soc. Mass Spectrom., 1 (1990) 92-98. 

C.J. Miles, D.R. Doerge and S. Bajic, Particle beam liquid chromatography-mass spectrometry of national pesticide survey analytes, Archives Environmental Contamination Toxicol., 22 (1992) 247-251. 

Based on a new technology, particle beam enhanced liquid chromatography-mass spectrometry expands a chemist s ability to analyse a vast variety of substances. Electron impact spectra from the system are reproducible and can be searched against standard or custom libraries for positive compound identification. Chemical ionization spectra can also be produced. Simplicity is a key feature. A simple adjustment to the particle beam interface is all it takes. 

This technique is complementary to the thermospray technique. Relative advances of the particles beam technique over thermospray include library searchable electron impact spectra, improved reproducibility, easier use and increased predictability over a broad range of compounds. But since a particle beam requires same sample volatility, very large and polar compounds such as proteins may not provide satisfactory results using particle beam liquid chromatography-mass spectrometry. Additionally, certain classes of compounds such as preformed ions, azo dyes and complex sugars may not yield satisfactory electron impact spectra, but can be run on thermospray. In other words, both liquid chromatography-mass spectrometry techniques complement each other s limitations and the analyst may want to add both to address a broader range of samples. 

Di Corcia and Marchetti [160] determined chlorinated phenoxy acid and ester type herbicides in amounts down to lmg kg-1 or lower in soil by liquid chromatography combined with particle beam mass spectrometry and ultraviolet absorption spectrometry. 

Kim et al. [161] used particle beam mass spectrometry and ultraviolet absorption spectrometry as detectors in a method for the determination of down to lppm of chlorinated phenoxy and ester herbicides in soil. 

Wilkes, J.G. Freeman, J.P. Heinze, T.M. Lay, J.O., Jr. Vestal, M.L. AC Corona-Discharge Aerosol-Neutralization Device Adapted to Liquid Chromatogra-phy/Particle Beam/Mass Spectrometry. Rapid Common. Mass Spectrom. 1995, 9, 138-142. 

Interfacing of solution-based separation techniques with mass spectrometry has historically been a challenge because of the incompatibility of the used solvent with the vacuum system. Standard electron impact (El) ionization with techniques such as particle beam require samples to be vaporized under high vacuum for ion formation to occur. 

The first approaches to the coupling of liquid-phase separation techniques with mass spectrometry were designed for HPLC needs, starting in the 1970s with since-forgotten techniques such as direct liquid introduction (DLI) and moving belt. In the 1980s, techniques such as thermospray, continuous-flow-fast atom bombardment (CF-FAB), and particle beam arose. 

Coupling of liquid chromatography with mass spectrometry provides unequivocal online spectrometric identification of tetracycline antibiotics in animal-derived foods. Typical applications of mass spectrometry in confirming tetracycline residues in edible animal products describe coupling of liquid chromatography with mass spectrometry via particle-beam (280), electrospray (292), or atmospheric pressure chemical ionization (307), using negative-ion detection interfaces. 

More ambitious attempts at measuring the heterogeneity of the atmospheric aerosol have been undertaken as well. Single-particle analysis by mass spectrometry was demonstrated by Sinha and co-workers (31, 32). In this technique, an aerosol sample is introduced into a vacuum chamber in the form of a particle beam. The particles are injected into a Knudsen cell oven, where they undergo many collisions with the cell wall and are ultimately vaporized and ionized. The ions are then mass-analyzed with a quad-rupole or sector mass spectrometer. So that individual particles can be analyzed, the flux of particles into the Knudsen cell is limited so that coincidence errors are minimized. Ion pulses from individual particles allow the determination of the amount of the species being analyzed in the particular particle. The sensitivity of the technique is limited. For sodium, the detection... 

Selected methods for determining vitamin K in a variety of foods are summarized in Table 13. The photodiode array detector lacks the required sensitivity for identifying phylloquinone in foods other than green leafy vegetables. Careri et al. (248) reported on the use of particle beam mass spectrometry for the determination and unequivocal identification of phylloquinone in some vegetable samples. The proposed LC-MS method permitted phylloquinone assay at levels down to 0.1 yug/g with high specificity. 

M Careri, A Mangia, P Manini, N Taboni. Determination of phylloquinone (vitamin K,) by high performance liquid chromatography with UV detection and with particle beam-mass spectrometry. Fre-senius J Anal Chem 355 48-56, 1996. 

The availability of commercial bench-top mass spectrometry detectors for HPLC is facilitating the development of HPLC-MS methods for many analytes. This is more common in pharmaceutical than food applications. As is generally the case, mass spectrometry is first being applied to standard solutions and relatively simple samples before being applied to more complex food matrices. A standard mixture of ten vitamers, AA, DHAA, PN, PL, PM, thiamine, nicotinic acid, nicotinamide, pantothenic acid and biotin, were recently determined by HPLC-particle beam... 

M Careri, R Cilloni, MT Lugari, P Manini. Analysis of water-soluble vitamins by high-performance liquid chromatography-particle beam-mass spectrometry. Anal Commun 33 159-162, 1996. 

J Yinon, TL Jones, LD Betowski. Particle beam liquid chromatography electron impact mass spectrometry of dyes. J Chromatogr 482 75-85, 1989. 

MC Carson, MA Ngoh, SW Hadley. Confirmation of multiple tetracycline residues in milk and oxytetracycline in shrimp by liquid chromatography-particle beam mass spectrometry. J Chromatogr B 712 113-128, 1998. 

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