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The analytical profile index (API) was invented in the 1970s in the United States by Pierre Janin of Analytab Products Inc. [2] The API test system is currently manufactured by bioMérieux. [3] The API range introduced a standardized and miniaturized version of existing techniques, which were considered complicated to perform and difficult to read.
Molecules are ionized using a vacuum ultraviolet (VUV) light source operating at atmospheric pressure (105 Pa), either by direct absorption followed by electron ejection or through ionization of a dopant molecule that leads to chemical ionization of target molecules. The sample is usually a solvent spray that is vaporized by nebulization and heat.
Oxidase-positive bacteria possess cytochrome oxidase or indophenol oxidase (an iron-containing hemoprotein). [5] These both catalyze the transport of electrons from donor compounds to electron acceptors (usually oxygen). The test reagent TMPD acts as an artificial electron donor for the enzyme oxidase.
Atmospheric pressure chemical ionization chamber cross section. Atmospheric pressure chemical ionization (APCI) is an ionization method used in mass spectrometry which utilizes gas-phase ion-molecule reactions at atmospheric pressure (10 5 Pa), [1] [2] commonly coupled with high-performance liquid chromatography (HPLC). [3]
The electron microprobe (electron probe microanalyzer) developed from two technologies: electron microscopy — using a focused high energy electron beam to impact a target material, and X-ray spectroscopy — identification of the photons scattered from the electron beam impact, with the energy/wavelength of the photons characteristic of the atoms excited by the incident electrons.
The electron capture detector is used for detecting electron-absorbing components (high electronegativity) such as halogenated compounds in the output stream of a gas chromatograph. The ECD uses a radioactive beta particle (electron) emitter in conjunction with a so-called makeup gas flowing through the detector chamber.
Most people will stop testing positive on a rapid antigen COVID-19 test within about 10 days, Cardona says. "Within 10 days after your initial positive test, you should convert back to negative ...
Positive material identification (PMI) is the analysis of a material, this can be any material but is generally used for the analysis of metallic alloy to establish composition by reading the quantities by percentage of its constituent elements. Typical methods for PMI include X-ray fluorescence (XRF) and optical emission spectrometry (OES). [1]