We have evaluated the use of “Dexsil 300 GC,” a polycarboranesioxane, as the stationary phase in the GC measurement of N,O-dipivalyl methyl esters of pure T3 and T4, and T3 from human serum.2 Unlike other stationary phases,Dexsil 300 GC is stable up to 500#{176}C, which greatlyminimizes background caused by column bleed (1). Excellentseparationsand detectionofT3 and T4 were obtained at a column...

The decay rate of 7Be depends on the electron density at the nucleus and therefore may vary with the chemical environments of the Be atom. Using a 100% efficiency high-purity germanium detector, the decay constants of Be in Be2C(OH2)4, Be(OH)2 and BeO have been measured at unprecedented high precision (of š0.01%), resulting in T1=2 D 53.69 d, 53.42 d, and 54.23 d, respectively. The observed dif...

We describe a micromethod for measuring hexachlorophene by use of gas-liquid chromatography with a 63Ni electron capture detector. The procedure requires 100 micronl of blood for extractions of hexachlorophene, and dichlorophene is added as an internal standard. CV is 3.4% over the concentration range of 500 to 1300 microng of hexachlorophene per liter of whole blood. This procedure permits rep...

A new electron capture detector (ECD) for the Agilent 6890 Series gas chromatograph (GC) allows very sensitive detection of nitroaromatic compounds at low picogram levels with a linear response over three orders of magnitude. Analysis of Nitroaromatics and Nitro-Polycyclic Aromatic Hydrocarbons by Capillary Gas Chromatography with the Agilent 6890 Micro-ECD This application note describes the p...

A new method for sampling and chemical analysis of alphacypermethrin in workplace air has been described. Air samples were taken using a glass tube filled with silica gel with chemically bounded octadecyl phase. Chromatographic determinations were conducted using an HP-5 capillary column (10 m x 0.53 mm) and an electron-capture detector. Alphacypermethrin recovery was 100.15%. The calculated de...

We used 100 microliters of plasma for the determination of diazepam. After the internal standard, prazepam, is added, the serum is directly extracted with diethyl ether, the extract is evaporated, the residue is dissolved in ethanol, and the drug is measured by gas-liquid chromatography, with use of an electron capture detector. With this procedure, 2.5 ng of diazepam in the sample can be speed...

Polychlorinated biphenyls (PCBs) are widely dispersed in the environment. Occupational exposure to PCBs takes place, e.g., in manufacture and repair of capacitors and transformers. A special type of exposure of workers to PCBs may occur in connection with accidents where capacitors or transformers containing PCBs products are damaged, as in the case of a fire or electric arcing. The quantitatio...

Introduction: The Monte Carlo simulation is used to enhance reliability in the experiments related to nuclear instruments. in addition, that is used to calculate the different components of the neutron and gamma ray fluxes in boron neutron capture therapy(BNCT) and neutron capture (NCT)applications. BNCT is one of the methods in radiotherapy, that is used the neutron beam for ki...

UNLABELLED Current electron detectors are either unable to image in vivo or lack sufficient spatial resolution because of electron scattering in thick detector materials. This study was aimed at developing a sensitive high-resolution system capable of detecting electron-emitting isotopes in vivo. METHODS The system uses a lens-coupled charge-coupled-device camera to capture the scintillation ...