PURPOSE The performance of liquid ionization chambers, which may prove to be useful tools in the field of radiation dosimetry, is based on several chamber and liquid specific characteristics. The present work investigates the performance of the PTW microLion liquid ionization chamber with respect to recombination losses and perturbations from ambient electric fields at various dose rates in con...

The electronic properties of liquid ammonia are investigated by a sequential molecular dynamics/quantum mechanics approach. Quantum mechanics calculations for the liquid phase are based on a reparametrized hybrid exchange-correlation functional that reproduces the electronic properties of ammonia clusters [(NH3)n; n=1-5]. For these small clusters, electron binding energies based on Green's func...

Liquid chromatography/mass spectrometry (LC/MS), combining good separation characteristics with highly specific and sensitive detection, is the method of choice for forensic trace analysis of explosives. Principles of operation and instrumentation of several LC/MS interface/ionization modes are described. Among the various LC/MS interfaces and ionization modes, electrospray ionization (ESI)-LC/...

an on-line automated method for photodegradation studies of isoproturon, diuron, atrazine, fenitrothion, and metoxuron by means of liquid chromatography/mass spectrometry (lc/ms) with particle beam (pb) interface is described. surface water samples were first spiked with 50 µg/l of each pesticide and then exposed to the radiation of the medium-pressure mercury lamp. next, in regular intervals o...

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...

Mass spectrometry (MS) owes its remarkable rise as a bioanalytical tool to the development of two “soft” ionization techniques: matrix-assisted laser desorption/ ionization (MALDI) (1,2) and electrospray ionization (ESI) (3). The salient feature of soft ionization is that a wide range of analytes, from small metabolites to very large biomolecular systems, can be transferred intact into the gas ...

Electrospray ionization is today the most widely used ionization technique in chemical and biochemical analysis. Interfaced with a mass spectrometer it allows the investigation of the molecular composition of liquid samples. With electrospray a large variety of chemical substances can be ionized. There is no limitation in mass which thus enables even the investigation of large noncovalent prote...

Abbreviations: CD: circular dichroism CLEC: cross linked enzyme crystals DDC: double dimer constructs ESI: electrospray ionization HOBT: hydroxybenzotriazole HPLC: high performance liquid hromatography KCS: kinetically controlled synthesis MALDI: matrix-assisted laser desorption ionization MAP: multiple antigen peptide system MS: mass spectrometry NMR: nuclear magnetic resonance SPS: solution p...

Migration of chemicals from plastic containers into drinks and liquids containing them, is supposed to be a hazardous phenomenon and results in many health problems. Sample preparation is of great importance due to trace amounts analysis of these compounds. In this research, dispersive liquid–liquid microextraction is applied for the extraction and preconcentration of the migrated compounds pri...