Californium-252 Plasma Desorption Mass Spectroscopy

Abstract

We have shown that 252Cf-PDMS is capable of producing mass spectra of quasi-molecular ions for a wide variety of compounds, including amino acids, moderately large peptides, nucleotides, and natural products. Positive and negative ion mass spectra can be obtained, and in many cases quasi-molecular ions are observed in both. The method is nondestructive, as only a relatively few molecules are used and samples can be recovered after the measurement is made. Fragmentation patterns are obtained which can yield structure information. The present sensitivity of the method is at the nanogram level and there are possibilities for reducing this to picograms. The mass resolution is sufficient to give elemental identification up to mass 500. This may be extended to higher masses with improved time-of-flight techniques. There are indications that 252Cf-PDMS may extend the mass range of molecules that can be studied to as high as 3000 or more.

Isolation and characterization of a resistant core peptide of recombinant human granulocyte‐macrophage colony‐stimulating factor (gm‐csf); confirmation of the gm‐csf amino acid sequence by mass spectrometry

“…Novel ionization methods (Macfarlane & Torgerson, 1976;Barber et al, 1981;Whitehouse et al, 1985;Karas & Hillenkamp, 1988) have led to the development of rapid, sensitive, and accurate methods for confirming the correctness of the gene product as well as detecting and identifying any desired or undesired alterations. Mapping approaches based on the analysis of the enzyme-generated peptide fragments by MS allow the precise determination of the molecular weights of the generated peptides, thus leading to the confirmation of the cDNA-derived sequence of the protein, as well as the identification of the disulfide bond pattern and other covalent modification sites.…”

Analysis of Saccharides by the Addition of Amino Acids

“…With an increase in the biological importance of oligo-or polysaccharides associated with cell-cell recognition, protein targeting, and metabolic diseases, polysaccharide and glycol-conjugate research has been attracting more attention [4,5]. Although different ionization methods [6][7][8][9][10][11][12][13] have been developed for the analysis of saccharides, matrix-assisted laser desorption/ionization (MALDI) [8] and ESI [11,[14][15][16][17][18] are the most used ionization methods. MALDI time-of-flight (TOF) MS has been used for the analysis of saccharides, and the sensitivity has been improved to the low femtomole level by reductive amination of the samples [19][20][21][22][23].…”

High Energy Sputtering from Cleaned Metal Foils

“…The positive and negative ion mass spectra from organic layers on metallic substrats show in many cases strong lines of undestroyed parent ions and a fragmentation pattern characteristic for the respective compound [1,2]. The fission fragments lose about lOkeV of their energy on passing a sample of 1 /*g/cm 2 thickness.…”