The radiometric methods, alpha (alpha)-, beta (beta)-, gamma (gamma)-spectrometry, and mass spectrometric methods, inductively coupled plasma mass spectrometry, accelerator mass spectrometry, thermal ionization mass spectrometry, resonance ionization mass spectrometry, secondary ion mass spectrometry, and glow discharge mass spectrometry are reviewed for the determination of radionuclides. Thes...

MS/MS daughter experiments were recorded for aflatoxins B1, B2, G1, G2, M1, M2, and aflatoxicol, using 3 ionization modes. Daughters were recorded from the molecular ion (M+) using electron impact ionization (EI). Daughters from the protonated molecules (MH+) were recorded in the positive ion mode and the daughters from the molecular anion (M-) were recorded in the negative ion mode using chemi...

A hybrid atmospheric pressure ion mobility spectrometer is described which exhibits resolving power approaching the diffusion limit for singly and multiply charged ions (over 200 for the most favorable case). Using an electrospray ionization source and a downstream quadrupole mass spectrometer with electron multiplier as detector, this ESI-IMS-MS instrument demonstrates the potential of IMS for...

The present study describes the fragmentation under electron ionization (EI) of gas phase serine and threonine amino acids. Ab initio methods were performed to calculate the fragmentation paths and interpret the mass spectra. The six lowest energy conformers of L-serine, L-threonine and L-allo-threonine were obtained with B3LYP, G3MP2 and MP2 methods. The adiabatic and vertical ionizat...

BACKGROUND Historically the success of mass spectrometry in the clinical laboratory has focused on drugs of abuse confirmations, newborn screening, and steroid analysis. Clinical applications of mass spectrometry continue to expand, and mass spectrometry is now being used in almost all areas of laboratory medicine. CONTENT A brief background of the evolution of mass spectrometry in the clinic...

The integration of a trapped ion mobility spectrometer (TIMS) with a mass spectrometer (MS) for complementary fast, gas-phase mobility separation prior to mass analysis (TIMS-MS) is described. The ion transmission and mobility separation are discussed as a function of the ion source condition, bath gas velocity, analysis scan speed, RF ion confinement, and downstream ion optical conditions. TIM...