Spark-Induced Breakdown Spectroscopy Electrode Assembly
AssigneeMassachusetts Institute of Technology
InventorsShane M. Tysk, John P. D'Angelo, William D. Herzog
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Abstract
A spark-induced breakdown spectroscopy apparatus can have a housing with an inlet and an outlet that define an analyte flow path. A laser can define a laser pathway generally transverse to an intersecting the analyte flow path. A pair of electrodes, which can have insulating shields, can be mounted within the housing and can define a spark path. An optical detection element defines an optical path. The apparatus can be used to identify an aerosolized analyte.
Claims53
A spark-induced breakdown spectroscopy apparatus, comprising:
- a) a housing having an inlet and an outlet defining an analyte flow path from the inlet to the outlet of the housing;
- b) a laser defining a laser pathway generally transverse to and intersecting the analyte flow path;
- c) a pair of electrode mounts within the housing, whereby tips of electrodes mounted in the housing define a line that is generally transverse to the analyte flow path;
- d) an insulating shield at each electrode mount, the insulating shields each having an edge, wherein the edges at least partially define a spark path that is transverse to and intersecting at a point in the analyte flow path and downstream along the analyte flow path from the point of intersection of the laser pathway and the analyte flow path, wherein the shields are each a sleeve that at least partially surrounds the electrode and extends beyond the tip of each electrode, and wherein the sleeves each define an opening at an end of the sleeve that is located beyond the tip of its respective electrode;
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- e) an optical detection element defining an optical path generally transverse to the analyte flow path and intersecting the analyte flow path at a point proximate to the intersection of the spark path and the analyte flow path.
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A method for conducting spark-induced breakdown spectroscopy, comprising the steps of:
- a) directing an analyte through a housing as an aerosol particle, wherein the housing has an inlet and an outlet defining an analyte flow path from the inlet to the outlet of the housing;
- b) directing a laser along a laser pathway generally transverse to and intersecting the analyte flow path;
- c) generating a spark across the analyte flow path between a pair of electrodes mounted within the housing, each electrode including a tip, a straight line extending between the tips of the electrodes being traversed by shields, a shield being mounted at each electrode, and wherein the shields each have an edge, the edges at least partially defining a spark path that is generally transverse to and intersecting at a point in the analyte flow path and downstream along the analyte flow path from the point of intersection of the laser pathway and the analyte flow path, wherein the shields are each a sleeve that at least partially surrounds the electrode and extends beyond the tip of each electrode, and wherein the sleeves each define an opening at an end of the sleeve that is located beyond the tip of its respective electrode, and wherein the edge is defined by the opening, whereby the spark ionizes the analyte to form a plasma;
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- d) receiving an emission from the ionized analyte by an optical detection element along an optical pathway to optically identify the analyte following ionization as it continues along its path through the housing.
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Dependencies are inferred from the claim text.