Fast atom bombardment mass spectrometry (FABMS). A study of surface coverage effects in FABMS

Barber, M.; Bordoli, Robert S.; Elliott, Gerard J.; Sedgwick, R. D.; Tyler, Andrew N.

doi:10.1039/f19837901249

Cited by 54 publications

(19 citation statements)

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“…16,[18][19][20] In the paper by Shyong and co-workers, the use of N-octylnicotinium bromide as a cationic surfactant to improve the detectability of polyanionic compounds was reported. There are a number of similarities between the observations made in this paper and the observations made in our own work.…”

Section: Alkali Cation Displacement Mechanismmentioning

confidence: 98%

The Use of Diethylamine to Determine the Number of Sulphonate Groups Present Within Polysulphonated Alkali Metal Salts by Electrospray Mass Spectrometry

Ballantine

Games

Slater

1997

Rapid Commun. Mass Spectrom.

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By using negative-ion diethylamine (DEA)-enhanced electrospray mass spectrometry under mild dissociative conditions, (a low voltage applied across the sampling cone aperture) a number of DEA molecules were observed to associate with the doubly charged acid ion of polysulphonated salts to form a series of higher-mass peaks. As the cone voltage was increased, these peaks degenerated into a series of lower-mass peaks. Each of the peaks contained within these series was separated by the mass of one DEA molecule. By further increasing the cone voltage, it was possible to dissociate all the DEA adducts from the acid ion.The maximum number of DEA molecules associated with the doubly charged acid ion could be correlated with the number of sulphonate sites present. This technique correctly identified the number of sulphonate groups contained within the series of compounds tested. A mechanism for these processes, based on the ability of protonated DEA to form ion pairs with sulphonate sites, is advanced. © 1997 by John Wiley & Sons, Ltd. Received 11 September 1996; Revised 17 February 1997; Accepted 17 February 1997 Rapid. Commun. Mass Spectrom. 11, 630-637 (1997 Polysulphonated salts are notorious for producing mass spectrometry signals of low intensity. 1 We have already shown that the addition of a basic amine to a polysulphonate in solution will dramatically enhance the signal intensity of the acid ions and just those fragment ions which had retained the capability to associate with alkali metal ions prior to diethylamine (DEA) intervention. All the signals which were due to alkali-metal association were greatly reduced or eliminated by the addition of DEA. 2,3 This unusual behaviour was further investigated and it was discovered that, under very mild ionization conditions, a number of DEA molecules could be seen attached to the acid ions. The maximum number of attached DEA molecules observed in any particular charge state was directly related to the number of sulphonate sites present on the compound tested.This paper discusses the relationship between the maximum number of adducted DEA molecules and the number of sulphonate sites, and how this relationship can be applied to determine the number of sulphonate sites in a series of polysulphonated salts. We also propose a possible mechanism for this process together with some experimental data to support our assumptions. EXPERIMENTAL Materials and methodsChemicals. All alkylamines and potassium indigo tetrasulphonate were purchased from Aldrich Chemical Co.Ltd. (Gillingham, Dorset, UK) and were used without further purification. Samples of Direct Blue 98, Direct Red 80, Direct Red 81, Direct Green 26, Acid Yellow 23, and Acid Orange 52 were all kindly donated by Dr. Peter Douglas and Richard Philips, Department of Chemistry, University of Wales, Swansea. Zeneca Colours S69177, S54412, and S69417 were all donated by Zeneca Ltd and used without further purification. Figure 1 shows the structures of the polysulphonates used in this investigation.Sample preparation. All an...

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Section: Alkali Cation Displacement Mechanismmentioning

confidence: 98%

The Use of Diethylamine to Determine the Number of Sulphonate Groups Present Within Polysulphonated Alkali Metal Salts by Electrospray Mass Spectrometry

Ballantine

Games

Slater

1997

Rapid Commun. Mass Spectrom.

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“…Fast atom bombardment mass spectrometry (FAB-MS) with unit mass resolution is an established qualitative technique that requires minimal sample preparation and that favorably ionizes hydrocarbon and fluorocarbon surfactants in commercial and environmental mixtures. 8, 19–21 As opposed to most LC-MS/MS methods, FAB-MS does not require prior knowledge of analytes of interest in order to analyze the samples (e.g. mass ranges, acidity/basicity, mixture composition and concentration).…”

Section: Introductionmentioning

confidence: 99%

Identification of Novel Fluorochemicals in Aqueous Film-Forming Foams Used by the US Military

Place

Field

2012

Environ. Sci. Technol.

409

484

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Aqueous film-forming foams (AFFFs) are a vital tool to fight large hydrocarbon fires and can be used by public, commercial, and military firefighting organizations. In order to possess these superior firefighting capabilities, AFFFs contain fluorochemical surfactants, of which many of the chemical identities are listed as proprietary. Large-scale controlled (e.g. training activities) and uncontrolled releases of AFFF have resulted in contamination of groundwater. Information on the composition of AFFF formulations is needed to fully define the extent of groundwater contamination and the first step is to fully define the fluorochemical composition of AFFFs used by the US military. Fast atom bombardment mass spectrometry (FAB-MS) and high resolution quadrupole-time-of-flight mass spectrometry (QTOF-MS) were combined to elucidate chemical formulas for the fluorochemicals in AFFF mixtures and, along with patent-based information, structures were assigned. Sample collection and analysis was focused on AFFFs that have been designated as certified for US military use. Ten different fluorochemical classes were identified in the seven military-certified AFFF formulations, and include anionic, cationic, and zwitterionic surfactants with perfluoroalkyl chain lengths ranging from 4-12. The environmental implications are discussed and research needs are identified.

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“…Similarly, the M,Br+/M+ abundance ratios obtained at varying analyte concentrations in LSIMS should not be useful in determining the CMC values for the alkyl quaternary ammonium salts since this ratio becomes constant once a monolayer of analyte forms on the surface and remains so at analyte concentrations greater than that expected for micelle formation. 11,17 This hypothesis contradicts the findings of a previous FAB study involving alkyl quaternary ammonium salts where a CMC value was assigned to the analyte concentration where the onset of M,Br+ formation in LSIMS was o b~e r v e d .~ Since the equilibrium constant, K , for dimerization [Eqn (la)] is related to the free energy of dimerization…”

Section: Resultsmentioning

confidence: 66%

Investigation of the clustering processes occurring in liquid secondary ion mass spectrometry for alkyl quaternary ammonium bromides

et al. 1996

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Fast atom bombardment mass spectrometry (FABMS). A study of surface coverage effects in FABMS

Abstract: A study of various surfactants using FABMS and surface tension measurements is described. A correlation between surface structure and FAB mass spectral response is reported with its possible significance in the ionisation mechanism.

Cited by 54 publications

References 0 publications

The Use of Diethylamine to Determine the Number of Sulphonate Groups Present Within Polysulphonated Alkali Metal Salts by Electrospray Mass Spectrometry

The Use of Diethylamine to Determine the Number of Sulphonate Groups Present Within Polysulphonated Alkali Metal Salts by Electrospray Mass Spectrometry

Identification of Novel Fluorochemicals in Aqueous Film-Forming Foams Used by the US Military

Investigation of the clustering processes occurring in liquid secondary ion mass spectrometry for alkyl quaternary ammonium bromides

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