Qualitative Analysis of Organic Compounds by Mass Spectrometry

Beynon, J. H.

doi:10.1038/174735a0

Cited by 94 publications

(49 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(By definition, the mass defect of 12 C is zero.) Thus, if the mass of a molecule can be measured with sufficiently high accuracy (in practice, Ϸ0.0003 Da for molecules up to Ϸ1,000 Da in mass), then its elemental composition can usually be determined uniquely from its mass alone (16,17). Fig.…”

mentioning

confidence: 99%

Petroleomics: Chemistry of the underworld

Marshall

Rodgers

2008

Proc. Natl. Acad. Sci. U.S.A.

601

565

View full text Add to dashboard Cite

Each different molecular elemental composition-e.g., CcHhNnOoSshas a different exact mass. With sufficiently high mass resolving power (m/⌬m 50% Ϸ 400,000, in which m is molecular mass and ⌬m50% is the mass spectral peak width at half-maximum peak height) and mass accuracy (<300 ppb) up to Ϸ800 Da, now routinely available from high-field (>9.4 T) Fourier transform ion cyclotron resonance mass spectrometry, it is possible to resolve and identify uniquely and simultaneously each of the thousands of elemental compositions from the most complex natural organic mixtures, including petroleum crude oil. It is thus possible to separate and sort petroleum components according to their heteroatom class (N nOoSs), double bond equivalents (DBE ‫؍‬ number of rings plus double bonds involving carbon, because each ring or double bond results in a loss of two hydrogen atoms), and carbon number. ''Petroleomics'' is the characterization of petroleum at the molecular level. From sufficiently complete characterization of the organic composition of petroleum and its products, it should be possible to correlate (and ultimately predict) their properties and behavior. Examples include molecular mass distribution, distillation profile, characterization of specific fractions without prior extraction or wet chemical separation from the original bulk material, biodegradation, maturity, water solubility (and oil:water emulsion behavior), deposits in oil wells and refineries, efficiency and specificity of catalytic hydroprocessing, ''heavy ends'' (asphaltenes) analysis, corrosion, etc.Fourier transform ͉ ion cyclotron resonance ͉ mass spectrometry ͉ petroleum ͉ fossil fuel

show abstract

mentioning

confidence: 99%

Petroleomics: Chemistry of the underworld

Marshall

Rodgers

2008

Proc. Natl. Acad. Sci. U.S.A.

601

565

View full text Add to dashboard Cite

show abstract

“…T he value of accurate mass measurements has been known to the mass spectrometry community for ϳ50 y [1]. For masses below ϳ500 Da, the number of unique elemental compositions corresponding to a given mass value is limited, and from a mass measurement made to an accuracy of Ͻ5 ppm an elemental composition can be deduced when valence rules and additional chemical information is considered [2][3][4].…”

mentioning

confidence: 99%

“…Although often considered together, high-resolution is not synonymous with accurate mass [19], and, in fact, the realization by Beynon in 1954 of the value of accurate measurements for the determination of elemental composition was first made with data produced by a single-focusing magnetic-sector instrument capable of only modest resolution (250, 10% valley definition) [1]. It should be remembered, however, that if the accurate mass of a compound is to be reliably determined, it is necessary to work with sufficient resolution so that homogenous peaks are mass measured.…”

mentioning

confidence: 99%

Electrospray mass spectrometry for the direct accurate mass measurement of ligands in complex with the retinoid X receptor α ligand binding domain

Lengqvist

Alvélius

Jörnvall

et al. 2005

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Accurate mass measurements are often used in the structural determination of unknown compounds of low molecular mass (i.e., below ϳ500 Da). Recently, it has been shown that accurate mass measurements also can be made on small denatured proteins (i.e., M r , ϳ17,000) to confirm their amino acid composition and identify the presence of isoforms. In the current report, we present nondenaturing electrospray (ES) mass spectrometry data on the direct accurate mass measurement of ligands in complex with the retinoid X receptor ligand binding domain (RXR LBD; M r 31,370.92). Average mass errors were below 0.198 Da, 6.3 ppm (standard deviation [SD], 0.146; n ϭ 10) for low-affinity fatty acid agonists analyzed in complex with the RXR LBD. Protein consumption was less than 15 pmol, with fatty acid ligands present at concentrations corresponding to their median effective concentration value (low micromolar, determined in transfection assays). Although determination of fatty acid mass was only sufficiently accurate to give nominal mass values, measurements were of sufficient accuracy to assign fatty acid chain length, degree of unsaturation, or cyclization. Using 17␤-estradiol as a control, the ability to observe specific ligand binding is shown for both high-and low-affinity RXR␣ agonists. In addition, binding of a novel synthetic receptor agonist XCT0315908 to the RXR␣ LBD is reported. This compound showed a high degree of complex formation, and the receptor-ligand complex could be mass measured with an average mass error of Ϫ0.024 Da, 0.8 ppm (SD, 0.092; n ϭ 9). Thus, specific binding of both nanomolar and micromolar affinity ligands to a nuclear receptor LBD can be directly observed using nondenaturing ES mass spectrometry and accurate mass measurements additionally can be made on intact complexes in the same experiment. This methodology also is applicable when ligands are present as components of mixtures. (J Am Soc Mass Spectrom 2005, 16, 1631-1640

show abstract

“…FT-ICR MS offers several advantages for characterizing multicomponent mixtures. For example, the high mass measurement accuracy of FT-ICR MS [7][8][9] limits the number of possible chemical formulas corresponding to an experimentally determined mass value [10].…”

mentioning

confidence: 99%