摘要:
A micro discharge device (MDD) ionizer and a method for fabricating the MDD ionizer are disclosed. The MDD ionizer includes a dielectric barrier having a first open end connected to an electrically conductive capillary tube and a second open end connected to a sample collection capillary tube. A circular high voltage electrode can be positioned around the dielectric barrier in close linear proximity to the conductive capillary tube and sealed by a non-conductive epoxy. A plasma discharge can be formed in a flow path through the dielectric barrier when an AC potential is applied between the high voltage electrode and the electrically conductive capillary tube utilizing an electronic controller. Such a plasma discharge in the flow path of the sample achieves soft ionization of gaseous sample molecules. The high pressure region generally occurs in the plasma region (where the ionization occurs). The ions thus are drawn (i.e., pushed or pulled) toward the high vacuum region located downstream where the detector(s) can be located.
摘要:
A sampling tape carries a plurality of elongated, spaced apart, gas sensitive regions which respond to different toxic gases. The regions can be in the form of elongated tracks which can be scanned simultaneously at multiple locations. A group of scanning locations along a track can provide sample signals for a selected gas from a plurality of locations. Signals from another track can relate to a different gas.
摘要:
A micro discharge device (MDD) capable of low voltage discharges in a variety of carrier gases for detection and/or ionization includes a sample introduction capillary having a first open end connected to a gas system and a second open end connected to a cylinder comprising a high dielectric constant material. A high voltage electrode can be placed in close proximity to the outer diameter of the cylinder and at a close linear distance to the second open end of the sample introduction capillary. A region can be formed inside the cylinder between the second end of the sample introduction capillary and the high voltage electrode wherein discharge can be located. An optical emission collector can be located through the flow manifold to a receiving location near the high voltage electrode within a region from inside the cylinder between the high voltage electrode and the manifold.
摘要:
A micro discharge device (MDD) capable of low voltage discharges in a variety of carrier gases for detection and/or ionization includes a sample introduction capillary having a first open end connected to a gas system and a second open end connected to a cylinder comprising a high dielectric constant material. A high voltage electrode can be placed in close proximity to the outer diameter of the cylinder and at a close linear distance to the second open end of the sample introduction capillary. A region can be formed inside the cylinder between the second end of the sample introduction capillary and the high voltage electrode wherein discharge can be located. An optical emission collector can be located through the flow manifold to a receiving location near the high voltage electrode within a region from inside the cylinder between the high voltage electrode and the manifold.
摘要:
An approach for analyzing fluid samples. The approach provides for segregating a sample into groups of analytes in a sample before being passed on to an analyzer such as a detector or separator. The sample may be run through a number of collectors connected in series each of which may adsorb analytes having a certain property which is different from a property of any of the other collectors in the series. After the adsorption of analytes, the collectors may be reconnected by a valve or fluid control mechanism from their series connection to a parallel connection to their respective analyzers. The analytes may be desorbed into a pulse in each of the collectors, which goes to the respective analyzer.
摘要:
A micro discharge device (MDD) ionizer and a method for fabricating the MDD ionizer are disclosed. The MDD ionizer includes a dielectric barrier having a first open end connected to an electrically conductive capillary tube and a second open end connected to a sample collection capillary tube. A circular high voltage electrode can be positioned around the dielectric barrier in close linear proximity to the conductive capillary tube and sealed by a non-conductive epoxy. A plasma discharge can be formed in a flow path through the dielectric barrier when an AC potential is applied between the high voltage electrode and the electrically conductive capillary tube utilizing an electronic controller. Such a plasma discharge in the flow path of the sample achieves soft ionization of gaseous sample molecules. The high pressure region generally occurs in the plasma region (where the ionization occurs). The ions thus are drawn (i.e., pushed or pulled) toward the high vacuum region located downstream where the detector(s) can be located.