Background: Radiotherapy is an important technique of cancer treatment using ionizing radiation. The determination of total dose in reference conditions is an important contribution to uncertainty that could achieve 2%. The source of this uncertainty comes from cavity theory that relates the in-air cavity dose and the dose to water. These correction factors are determined from Monte Carlo calcu...

Ambient ionization is a set of mass spectrometric ionization techniques performed under ambient conditions that allows the direct analysis of sample surfaces with little or no sample pretreatment. Using combinations of different types of sample introduction systems and ionization methods, several novel techniques have been developed over the last few years with many applications (e.g., food saf...

a three-step selective photo-ionization for gd155 and gd157 isotopes by pulsed laser wasevaluated numerically. due to large thermal neutron absorption cross sections, these two isotopes innatural gadolinium are good candidates as burnable poison to control reactivity early in the fuel cycleand allow extended fuel burn up. rate equations have been used to calculate the dynamics of the isotopepop...

Moxidectin, a potent new endo- and ectoparasitic agent, is determined in cattle tissues by liquid chromatography (LC) with fluorescence detection. The original confirmatory method for moxidectin in cattle fat, the target tissue for regulatory purposes, was LC with mass spectrometry (MS) using thermospray (TSP) ionization and selected ion monitoring. As newer ionization techniques for LC/MS made...

ingly undesirable, especially when alternative techniques based upon physicochemical substance properties are available. Toxins generally are analyzed using high performance liquid chromatography (HPLC) techniques with various unspecific detectors. Therefore, subsequent confirmation is needed to ensure that these methods do not yield any false responses. While enzyme immunoassay screens are ava...

BACKGROUND One driving motivation in the development of point-of-care (POC) diagnostics is to conveniently and immediately provide information upon which healthcare decisions can be based, while the patient is on site. Ambient ionization mass spectrometry (MS) allows direct chemical analysis of unmodified and complex biological samples. This suite of ionization techniques was introduced a decad...

The coupling of liquid chromatography and mass spectrometry (LC/MS) has been established as one of the most powerful tools in analytical chemistry and has resulted in important advances especially in biomedical and biochemical research. The predominantly used interfaces are electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI). Non-polar compounds, however, are diffi...