Field desorption mass spectroscopy

Various ionization methods were used to bombard phenol-formaldehyde oligomers in mass spectroscopic analysis. The molecular weights of resole resins were calculated using field desorption mass spectroscopy of acetyl-derivatized samples.74 Phenol acetylation was used to enable quantitative characterization of all molecular fractions by increasing the molecular weights in increments of 42. 

Hufford et al [57] used proton and 13C NMR spectrometric data to establish the novel sulfur-containing microbial metabolite of primaquine. Microbial metabolic studies of primaquine using Streptomyces roseochromogenus produced an A-acety-lated metabolite and a methylene-linked dimeric product, both of which have been previously reported, and a novel sulfur-containing microbial metabolite. The structure of the metabolite as an S-linked dimer was proposed on the basis of spectral and chemical data. The molecular formula C34H44N604S was established from field-desorption mass spectroscopy and analytical data. The 1H- and 13C NMR spectra data established that the novel metabolite was a symmetrical substituted dimer of primaquine A-acetate with a sulfur atom linking the two units at carbon 5. The metabolite is a mixture of stereoisomers, which can equilibrate in solution. This observation was confirmed by microbial synthesis of the metabolite from optically active primaquine. 

Lattimer, R.P. Harmon, D.J. Welch, K.R. Characterization of Low Molecular Weight Polymers hy Liquid Chromatography and Field Desorption Mass Spectroscopy. Anal. Chem. 1979,57,293-296. 

Fibrillin, calcium binding, 46 473, 474, 477 Fibulin-I, calcium binding, 46 473 Field desorption mass spectroscopy, 28 6, 21 Field effects, of astatophenols, 31 66 Fine structure, 13 193-204 Fingerprinting of polymetalates, 19 246-248 Finite perturbation theory, 22 211, 212 First transition series, substitution, transferrins, 41 423 26... 

Schulton W.D. Lehmman, High-Resolution Field Desorption Mass Spectroscopy. Part VII. Explosives and Explosive Mixtures , AnalChem-Acta 93,19-31 (1977) 153) A. Aim et al,... 

Divalent samarocene complexes also show unique reactivity toward a-olefins [55]. Bis-Cp complexes of type 13 display high polymerization activity toward ethylene, but yield rather low molecular weights (M < 25 000) [56]. The polymerization mechanism was investigated using field desorption mass spectroscopy (FD-MS) and proposed as outlined in Scheme 2. A 2 1 complex of 13 with ethyl-... 

Lattimer, R. P. and Welch, K. R., Direct analysis of p>ol3mier chemical mixtures by field desorption mass spectroscopy. Rubber Chem. TechnoL, 53,151,1980. Saito, J., Toda, S., and Tanaka, S., Analysis of polyalkylene oxides by field desorption mass spectrometry, Shitsuryo Bunseki, 28,175,1980. 

H.U. Winkler, H.D. Beckey, Field desorption mass spectroscopy of peptides, Biochem. Biophys. Res. Commun. 46 391-398 (1972)... 

The determination of lithium in water is carried out by AAS (methods 3.3.1.2 and 3.3.1.3), or by flame photometry (method 3.3.1.1) - still in use today - according to the "universal method" proposed by Schuhknecht/ Schinkel as described in the section on "Sodium". Since a concentration process is necessary in the case of concentrations of lithium ions below 1 mg/1, a number of departures from the method given for sodium are necessary. Direct determination of traces of lithium is also possible using "stable isotope dilution and field desorption mass spectroscopy" (Schulten et al. 1979). 

A number of structures, as determined by field desorption mass spectroscopy (FDMS), for polymeric products obtained by the pyrolysis of anthracene have been proposed by Lewis [86], where molecular weights up to 1400 have been identified ... 

Numerous procedures, by a variety of different instruments, are available to quantify the amount of thallium present in hair, blood, tissue, saliva, and urine (for reviews, see [9,81]). Instrumentation used includes emission spectrography, flame and flameless atomic absorption spectroscopy (AAS), voltammetry, neutron activation analysis, and field desorption mass spectroscopy [13,17,82-90]. Field desorption mass spectroscopy when combined with stable isotope dilution can detect fentomole quantities and has value in that no tissue preparation (other than homogenization) is required [65,82,89], The use of these two methods, however, is restricted to specialized laboratories. 

H-D. Beckey, Principles of Field Ionization and Field Desorption Mass Spectroscopy, Pergamon Press, New York, NY, USA, 1977. 

Lattimer RP, Harmon DJ, Hansen GE. Determination of molecular weight distributions of polystyrene oligomers by field desorption mass spectroscopy. Anal Chem 1980 52 1808-1811. 

Obata and co-workers [7] separated stereoisomeric products formed during the synthesis of (2S, 3S)-2,3 bntane diyl (2S, 4S) 2, 4 pentane diyl and (2S, 5S) hexane diyl bis (4-vinyl benzoate) by chiral HPLC and characterised these polymers by high resolution field desorption mass spectroscopy (HR-FD-MS) and C-NMR. 

Field desorption. APEs give very simple mass spectra by field desorption, showing almost exclusively the molecular or [M + 1] ions, demonstrated to a degree of ethoxylation of about 16 (22,82,86). FD can be used for quantitative determination of NPE in environmental samples (87,88). Field desorption mass spectroscopy was used to characterize fractions collected after HPLC separation of APE (86). The HPLC system separated only by alkyl chain length, giving three fractions corresponding to all ethoxylates of C, ... 

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