Search results
Results from the WOW.Com Content Network
This allows the generation of stable cold plasma even in ambient air. In the simplest application, ambient air can be directly analyzed. Ionization in flow enables high ion transmission since ion loss is significantly reduced compared to the most commonly used spraying methods in mass spectrometry (cf. ESI, APCI). Consequently, this leads to an ...
In the late 1970s an APCI mass spectrometer system (the TAGA, for Trace Atmospheric Gas Analyzer), mounted in a van for mobile operation, was introduced by SCIEX, [19] [20] providing high sensitivity for monitoring polar organics in ambient air in real time. In 1981 a triple quadrupole mass spectrometer version was produced, allowing real-time ...
The mass spectrometry analysis, however, takes place at high vacuum condition. Therefore, ions entering the mass spectrometer, first go through a source - to - analyzer interface (vacuum interface), which was designed in order to bridge the atmospheric pressure region to the mass spectrometer vacuum. It also minimizes spectrometer contamination.
Atmospheric pressure photoionization (APPI) is a soft ionization method used in mass spectrometry (MS) usually coupled to liquid chromatography (LC). 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 ...
Dimensionless numbers (or characteristic numbers) have an important role in analyzing the behavior of fluids and their flow as well as in other transport phenomena. [1] They include the Reynolds and the Mach numbers, which describe as ratios the relative magnitude of fluid and physical system characteristics, such as density, viscosity, speed of sound, and flow speed.
Atmospheric pressure laser ionization is an atmospheric pressure ionization method for mass spectrometry (MS). Laser light in the UV range is used to ionize molecules in a resonance-enhanced multiphoton ionization (REMPI) process. It is a selective and sensitive ionization method for aromatic and polyaromatic compounds. [1]
Although atmospheric pressure MALDI is performed under ambient conditions, [15] it is not generally considered to be an ambient mass spectrometry technique. [16] [17] Laser ablation was first coupled with mass spectrometry in the 1980s for the analysis of metals using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS). [18]
The pH range is commonly given as zero to 14, but a pH value can be less than 0 for very concentrated strong acids or greater than 14 for very concentrated strong bases. [2] The pH scale is traceable to a set of standard solutions whose pH is established by international agreement. [3]