Patent Description:
Laser ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) or Laser ablation Inductively Coupled Plasma Optical Emission Spectrometry (LA-ICP-OES) techniques can be used to analyze the composition of a target (e.g., a solid or liquid target material). Often, a sample of the target is provided to an analysis system in the form of an aerosol (i.e., a suspension of solid and possibly liquid particles and/or vapor in a carrier gas, such as helium gas). The sample is typically produced by arranging the target within a laser ablation chamber, introducing a flow of a carrier gas within the chamber, and ablating a portion of the target with one or more laser pulses to generate a plume containing particles and/or vapor ejected or otherwise generated from the target (hereinafter referred to as "target material"), suspended within the carrier gas. Entrained within the flowing carrier gas, the target material is transported to an analysis system via a transport conduit to an ICP torch where it is ionized. A plasma containing the ionized particles and/or vapor is then analyzed by an analysis system such as an MS or OES system.

Conventional techniques such as LA-ICP-MS and LA-ICP-OES, however, are undesirably slow to carry out high-resolution compositional analysis (i.e., "imaging") of a target within a reasonable time frame. For example, current techniques undesirably take up to about <NUM> hours to image an area of <NUM><NUM> at a pixel resolution of <NUM>. In addition, current techniques such as LA-ICP-MS and LA-ICP-OES are also not sensitive enough for high-resolution imaging or analysis of micron-sized and sub-micron side particles (e.g., nanoparticles). nanoparticles). Example embodiments disclosed herein address these and other problems associated with conventional compositional analysis techniques. <CIT> provides certain disclosures in the field of determining the surface contamination of a solid. <CIT> provides certain disclosures in the field of analysing steel. <CIT> provides certain disclosures in the field of laser irradiation. <CIT> and <CIT> provide certain disclosures in the field of laser spectrochemical analysis. In particular, <CIT> discloses, on <FIG> and 4b, a laser ablation mass spectrometer for handling target material removed from a laser ablation site of a target S, the apparatus comprising: a sample capture cell <NUM> including: a capture cavity having an opening formed in a surface at a first region of the capture cell, the capture cavity being configured to receive, through the opening, target material ejected or generated from the laser ablation site when the surface faces toward the target S and the sample capture cell <NUM> is spaced apart from the target; a first inlet between the outer tube <NUM> and the inner tube <NUM> extending from the capture cavity to an exterior of the sample capture cell defining a front end region, the first inlet being configured to transmit a flow of a carrier gas from a first location adjacent to the exterior of the sample capture cell into the capture cavity; an outlet <NUM> in fluid communication with the capture cavity and configured to receive, from the capture cavity, the carrier gas and at least a portion of the removed target material; and a second inlet being an upper part of the inner tube <NUM> extending from the capture cavity to an upper surface of the exterior of the sample capture cell, the second inlet being configured to transmit a second flow of the carrier gas from a second location adjacent to the exterior of the capture cell into the capture cavity, the second inlet and the capture cavity being configured such that laser light is transmittable through the second inlet and the capture cavity and onto a region of the target when the sample capture cell <NUM> is spaced apart from the target, a guide wall being a bottom part of the inner tube <NUM> exposed within the capture cavity and configured to direct a flow of the carrier gas within the capture cavity between the first inlet and the outlet such that at least a portion of the target material received within the capture cavity are transferable into the outlet as a sample.

Example embodiments are described below with reference to the accompanying drawings. Many different forms and embodiments are possible without deviating from the teachings of the invention and so the disclosure should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will convey the scope of the invention to those skilled in the art, the scope of the invention being defined by the claims. In the drawings, the sizes and relative sizes of components may be exaggerated for clarity. It is to be understood that various orientational terms such as "front" and "back" and "rear", "left" and "right", "top" and "bottom", "upper" and lower" and the like are used herein only for convenience, and not with the intention of limiting what is described to any absolute or fixed orientation relative to any environment in which any described structures may be used. Unless otherwise specified, a range of values, when recited, includes both the upper and lower limits of the range, as well as any sub-ranges therebetween.

<FIG> schematically illustrates one embodiment of an apparatus for handling a target and for handling target material ejected from or otherwise generated from the target, and includes a cross-sectional view of a sample chamber, a sample capture cell and a target holder.

Referring to <FIG>, an apparatus, such as apparatus <NUM>, for handling a target and for handling target material ejected from or otherwise generated from the target may include a sample chamber <NUM> configured to accommodate a target <NUM> within an interior <NUM> thereof, a sample generator <NUM> configured to remove a portion of the target <NUM> (which may be subsequently captured as a sample) and an analysis system <NUM> configured to analyze a composition of the sample. Examples of materials that can be provided as a target <NUM> include, for example, archaeological materials, biological assay substrates and other biological materials, ceramics, geological materials, pharmaceutical agents (e.g., pills), metals, polymers, petrochemical materials, liquids, semiconductors, etc. The apparatus <NUM> may optionally include a sample preparation system <NUM> configured to excite (e.g., ionize, atomize, illuminate, heat, or the like or a combination thereof) one or more components of the sample before the sample is analyzed by the analysis system <NUM>. As will be described in greater detail below, the sample preparation system <NUM> may include a plasma torch (e.g., an ICP torch), or the like. Further, the analysis system <NUM> may be provided as an MS system, an OES system, or the like.

The sample chamber <NUM> may include a frame <NUM> having an optical port <NUM> extending therethrough to permit optical communication between the sample generator <NUM> and the interior <NUM> of the sample chamber <NUM>. Optionally, a transmission window <NUM> may be coupled to the frame <NUM> and to span the optical port <NUM>. The transmission window <NUM> is typically formed of a material (e.g., quartz) that is at least substantially transparent to laser light generated by the sample generator <NUM>. The transmission window <NUM> may also be sealed to the frame <NUM> to prevent dust, debris or other unwanted gases or other sources of contamination from entering into the interior <NUM> through the optical port <NUM>. In one embodiment, the transmission window <NUM> is be sealed to the frame <NUM> also to prevent particles ejected from the target <NUM>, vapor generated from the target <NUM>, etc., (the particles, vapor, etc., being collectively referred to herein as "target material", which is removed from the target <NUM>), carrier gas or other fluids present within the interior <NUM>, from exiting the sample chamber <NUM> through the optical port <NUM>. Although the frame is illustrated as a single, integrally-formed piece, it will be appreciated that the frame <NUM> may be formed of multiple components that are coupled together, as is known in the art.

The sample chamber <NUM> may further include one or more injection nozzles <NUM> each configured to introduce, into the interior <NUM>, a fluid such as a carrier gas (e.g., helium, argon, nitrogen, or the like or a combination thereof) at a flow rate in a range from <NUM>/min to <NUM>/min (e.g., in a range from <NUM>/min to <NUM>/min, or <NUM>/min, or thereabout). For example, each injection nozzle <NUM> may be inserted through a fluid port in the frame <NUM> and include an inlet configured to be fluidly coupled to a fluid source (e.g., a pressurized fluid source) outside the sample chamber <NUM> and an outlet exposed within the interior <NUM> the sample chamber <NUM>. Seals (not shown) may be provided between frame and the injection nozzles <NUM> to fluidly isolate the interior <NUM> of the sample chamber <NUM> with the environment outside the sample chamber <NUM>. Upon introducing a carrier gas into the interior <NUM>, a flow of the carrier gas (also referred to herein as a "carrier gas flow") is generated within the interior <NUM>. It will be appreciated that the velocity and direction of the carrier gas flow at different locations within the interior <NUM> can vary depending upon: the shape and size of the interior <NUM> of the sample chamber <NUM>, the configuration of the one or more injection nozzles <NUM>, the flow rate with which carrier gas is introduced into the interior <NUM> by any particular injection nozzle <NUM>, or the like or a combination thereof. In one embodiment, the pressure within the interior <NUM> can be maintained (e.g., to a pressure less than or equal to <NUM> psi) by controlling the flow rate with which carrier gas is introduced into the interior <NUM>.

The apparatus <NUM> may further include a target positioning system configured to adjust the position of the target <NUM> relative to the optical path <NUM>. In one embodiment, the positioning system includes a target holder <NUM> configured to support the target <NUM>, a carriage <NUM> configured carry the target holder <NUM>, a base <NUM> configured to support the carriage <NUM> within the interior <NUM> and a positioning stage <NUM> configured to move the carriage <NUM>. Although the target holder <NUM> and the carriage <NUM> are illustrated as separate, separatable components, it will be appreciated that the target holder <NUM> and the carriage <NUM> may be integrally formed. Optionally, a height-adjustment mechanism (not shown) such as a micrometer can be provided to adjust a position of the target holder <NUM> along a vertical direction (e.g., along the optical path <NUM>) to ensure that the target <NUM> is arranged at a suitable or beneficial position within the interior <NUM>.

The positioning stage <NUM> may be configured to linearly translate the carriage <NUM> along at least one direction (e.g., an X-direction, a Y-direction orthogonal to the X-direction, or the like or a combination thereof) relative to the optical path <NUM>, or may be configured to rotate the carriage <NUM> relative to the optical path <NUM>, or the like or a combination thereof. In one embodiment, the positioning stage <NUM> and the frame <NUM> may both rest on a common support surface such as a table (not shown). A portion of the frame <NUM> may be spaced apart from the support surface to define a stage-receiving space therebetween, and the positioning stage <NUM> may be disposed in the stage-receiving space.

The base <NUM> may include a first side <NUM> exposed within the interior <NUM> and a second side <NUM> opposite the first side <NUM>. The base <NUM> may be coupled to the frame <NUM> so as to fluidly isolate the interior <NUM> of the sample chamber <NUM> with the environment outside the sample chamber <NUM>. Thus, as exemplarily illustrated, the carriage <NUM> and the positioning stage <NUM> are disposed at opposite sides of the base <NUM>. To facilitate movement and beneficial positioning of the target <NUM> within the interior <NUM>, the carriage <NUM> is magnetically coupled to the positioning stage <NUM> through the base <NUM>. For example, carriage <NUM> may include one or more magnets (not shown) arranged therein and the positioning stage <NUM> may include an end effector <NUM> having one or more magnets attached thereto. An orientation of the magnets within the carriage <NUM> and the end effector <NUM> may be selected to generate an attractive magnetic field extending between the end effector <NUM> and the carriage <NUM>, through the base <NUM>. It will be appreciated that the base <NUM> may be constructed in any suitable or beneficial manner to transmit a magnetic field of sufficient strength between the end effector <NUM> and the carriage <NUM>. For example, the base <NUM> may be formed from a material such as a metal, a glass, a ceramic, a glass-ceramic, or the like. In one embodiment, the base <NUM> may include a material formed of fluorphlogopite mica in a matrix of borosilicate glass.

To facilitate movement of the carriage <NUM> across the first side <NUM> of the base <NUM>, the first side <NUM> may have a relatively smooth surface (e.g., with a surface roughness, Ra, of about <NUM> to about <NUM>). In one embodiment, the positioning system may further include one or more bearings coupled to the carriage <NUM> and configured to contact the first side <NUM> of the base <NUM>. Although the apparatus <NUM> is illustrated as including the target positioning system, it will be appreciated that the target positioning system may be omitted, modified or substituted for any other suitable or beneficial mechanism for adjusting the position of the target <NUM> relative to the optical path <NUM>.

Constructed according to the various embodiments exemplarily described above, the target positioning system ensures repeatable lateral angular and positioning of the target <NUM> within the interior <NUM>, with low movement lag and motion hysteresis.

The sample generator <NUM> is configured to direct laser light along an optical path <NUM>, through the optical port <NUM> and into the interior <NUM> of the sample chamber <NUM> to impinge upon the target <NUM>. The laser light may be directed along the optical path <NUM> as one or more laser pulses generated by one or more lasers. One or more characteristics of the laser pulses may be selected or otherwise controlled to impinge a region of the target <NUM> to ablate a portion of the target <NUM>. Characteristics that may be selected or otherwise controlled may, for example, include wavelength (e.g., in a range from about <NUM> to about <NUM>, such as <NUM>, <NUM>, <NUM>, or the like), pulse duration (e.g., in a range from about <NUM> femtoseconds to about <NUM> nanoseconds), spot size (e.g., in a range from about <NUM> to about <NUM>, or the like), pulse energy, average power, peak power, temporal profile, etc. The sample generator <NUM> may also include laser optics (e.g., one or more lenses, beam expanders, collimators, apertures, mirrors, etc.) configured to modify laser light generated by one or more of the lasers. As used herein, a region of the target <NUM> that is impinged by a laser pulse is referred to as a "laser ablation site". Upon being ablated, target material is removed from a region of the target <NUM> located within or adjacent to the laser ablation site to form a plume containing the target material.

To facilitate handling of the target material (e.g., so that the composition of the target material can be analyzed at the analysis system <NUM>) the apparatus <NUM> may include a sample capture cell <NUM> configured to capture the target material when it is arranged operably proximate to the target <NUM>. Target material captured by the sample capture cell <NUM> is also herein referred to as a "sample" or a "target sample". The apparatus <NUM> may further include a transport conduit <NUM> configured to transport the sample to the sample preparation system <NUM>. In the illustrated embodiment, the apparatus may include a cell support <NUM> coupled to the sample chamber <NUM> (e.g., at the frame <NUM>) to fix the sample capture cell <NUM> within the interior <NUM>.

In one embodiment, the aforementioned optional height-adjustment mechanism may be used to adjust the height of the target holder <NUM> (and, thus, the target <NUM>) relative to the sample capture cell <NUM> to ensure that the sample capture cell <NUM> is operably proximate to the target <NUM>. In another embodiment, a height adjustment mechanism such as a micrometer may be optionally provided to adjust a position of the sample capture cell <NUM> relative to the target <NUM> (e.g., along the optical path <NUM>) to ensure that the sample capture cell <NUM> is arranged at a suitable or beneficial position within the interior <NUM>. Thus, in addition to (or instead of) adjusting a position of the target <NUM> relative to the sample capture cell <NUM>, the position of the sample capture cell <NUM> relative to the target <NUM> may be adjusted to ensure that the sample capture cell <NUM> is operably proximate to the target <NUM>. In one embodiment the sample capture cell <NUM> is operably proximate to the target <NUM> when the sample capture cell <NUM> is spaced apart from the target <NUM> by a gap distance, d (see, e.g., <FIG>) in a range from <NUM> to <NUM> (e.g., in a range from <NUM> to <NUM>, or in a range from <NUM> to <NUM>). It will be appreciated, however, that depending on factors such as the carrier gas flow velocity within a region of the interior <NUM> between the sample capture cell <NUM> and the target <NUM>, the gap distance can be less than <NUM> or greater than <NUM>, and may even contact the target <NUM>.

<FIG> is a cross-sectional view, taken along line II-II shown in <FIG>, schematically illustrating the sample capture cell shown in <FIG> according to one embodiment. <FIG> is a plan view schematically illustrating a first inlet, a second inlet, a capture cavity and an outlet of the sample capture cell when viewed in the direction indicated along line IIA-IIA in <FIG>. <FIG> is a plan view illustrating the first inlet, second inlet, capture cavity and outlet of the sample capture cell when viewed in the direction indicated along line IIB-IIB in <FIG>. <FIG> is a cross-sectional view schematically illustrating laser light directed through the second inlet and capture cavity of the sample cell onto a target at a laser ablation site, and a resultant plume containing the target material from the laser ablation site into the capture cavity of the sample cell. <FIG> is a perspective, cross-sectional view schematically illustrating characteristics of the flow of carrier gas within the interior of the sample chamber into the capture cavity of the sample capture cell shown in <FIG>. <FIG> is an enlarged, top plan view schematically illustrating the characteristics of the flow of carrier gas shown in <FIG> into the capture cavity of the sample capture cell shown in <FIG>. <FIG> is an enlarged perspective, cross-sectional view of the schematic shown in <FIG>, schematically illustrating characteristics of the flow of carrier gas through an opening of the capture cavity and into the outlet of the sample capture cell shown in <FIG>, from a region between the sample capture cell and the target. <FIG> is an enlarged side, cross-sectional view of the schematic shown in <FIG>, schematically illustrating characteristics of the flow of carrier gas through the second inlet and into the outlet of the sample capture cell shown in <FIG>.

Referring to <FIG>, <FIG>, the sample capture cell <NUM> may generally be characterized as having an upper surface <NUM> (e.g., configured to generally face toward the sample generator <NUM>) and a lower surface <NUM> (e.g., configured to generally face toward the target <NUM>), a front end region and a back end region opposite the front end region. Generally, the sample capture cell <NUM> is arranged within the interior <NUM> such that the front end region is disposed upstream of the back end region, relative to the predominant direction of the carrier gas flow at the location in the interior <NUM> where the sample capture cell <NUM> is arranged. In one embodiment, a surface of the sample capture cell <NUM> defining the front end region is configured so as to be convexly-curved. For example, and as best shown in <FIG>, the surface of the sample capture cell <NUM> defining the front end region is circularly curved, centered on an axis of a second inlet <NUM> (discussed in greater detail below) with a radius in a range from <NUM> to <NUM>, or thereabout). It will be appreciated, however, that depending on factors such as the predominant direction of the carrier gas flow at the location in the interior <NUM> where the sample capture cell <NUM> is arranged, the location of the second inlet <NUM> within the sample capture cell <NUM>, and other dimensions of the sample capture cell <NUM>, the geometric configuration of the surface defining the front end region of the sample capture cell <NUM> may be varied in any manner that may be suitable or beneficial. It will further be appreciated that the location of the sample capture cell <NUM> within the interior <NUM> can be selected based upon factors such as the geometry of the interior <NUM>, and the number and location of injection nozzles <NUM> generating the carrier gas flow within the interior <NUM>. For example, if the interior <NUM> has a cylindrical geometry, and if only one injection nozzle <NUM> is used to introduce carrier gas into the interior <NUM> along the diameter of the cylindrical interior <NUM> at the aforementioned flow rate, then the sample capture cell <NUM> can be located at or near the center of the interior <NUM>.

According to one embodiment, the sample capture cell <NUM> may further include a capture cavity <NUM>, a first inlet <NUM> in fluid communication with the capture cavity <NUM>, an outlet <NUM> in fluid communication with the capture cavity <NUM>, and a guide wall <NUM> exposed within the capture cavity <NUM>. In a further embodiment, the sample capture cell may further include the aforementioned second inlet <NUM> in fluid communication with the capture cavity <NUM>. In one embodiment, the sample capture cell <NUM> can be provided as a monolithic body formed of any suitable material such as a glass, a ceramic, a polymer, a metal, or the like or a combination thereof. Moreover, two or more or all of the capture cavity <NUM>, the first inlet <NUM>, the second inlet <NUM>, the outlet <NUM>, and the guide wall <NUM>, may be integrally formed within the body by conventional techniques (e.g., by machining, grinding, cutting, drilling, <NUM>-D printing, etc.). In another embodiment, however, two or more or all of the capture cavity <NUM>, the first inlet <NUM>, the second inlet <NUM>, the outlet <NUM>, and the guide wall <NUM>, may be separately formed from different components, which are subsequently coupled together.

The capture cavity <NUM> extends from an opening <NUM> formed in the lower surface <NUM> of the sample capture cell <NUM> and is configured to receive, through the opening <NUM>, the plume containing the target material ejected or otherwise generated from the laser ablation site on the target <NUM> when the sample capture cell <NUM> is arranged operably proximate to the target <NUM>. In an embodiment in which the sample capture cell <NUM> is spaced apart from the target <NUM>, carrier gas adjacent to the target <NUM> can be also be transmitted into the capture cavity <NUM> through the opening <NUM>. In the illustrated embodiment, the guide wall <NUM> defines the extent (e.g., lateral, vertical, etc.) of the capture cavity <NUM> within the sample capture cell <NUM>. In one embodiment, the volume of the capture cavity <NUM> can be in a range from <NUM><NUM> to <NUM><NUM> (e.g., <NUM><NUM>, or thereabout). It will be appreciated, however, that depending on factors such as the carrier gas flow velocity within the region of the interior <NUM> where the sample capture cell <NUM> is located, the size of the plume of target material, etc., the volume of the capture cavity <NUM> can be less than <NUM><NUM> or greater than <NUM><NUM>.

As best shown in <FIG> and <FIG>, a transition region of the guide wall <NUM> extending from the lower surface <NUM> into the interior of the sample capture cell <NUM> is rounded or chamfered. By providing a rounded or chamfered transition region, the turbulence of a surface flow <NUM> of carrier gas entering into the capture cavity <NUM> from the a region near the surface of the target <NUM> through the opening <NUM> can be controlled to be suitably or beneficially small. In one embodiment, the round or chamfer of the transition region may have a radius of <NUM>, or thereabout. It will be appreciated, however, that depending on factors such as the carrier gas flow velocity within a region of the interior <NUM> between the sample capture cell <NUM> and the target <NUM> and the aforementioned gap distance, the radius of the transition region can be significantly more or less than <NUM>. A more detailed rendering of the flow of carrier gas into the capture cavity <NUM> via the opening <NUM> is exemplarily and schematically illustrated in <FIG> and <FIG>. In some embodiments, the sample capture cell <NUM> can be configured such that the surface flow <NUM> is sufficient to lift target material from the surface of the target <NUM> into the capture cavity <NUM> through the opening <NUM> (where, thereafter, it can be transferred into the outlet <NUM>) when the sample capture cell <NUM> is operably proximate to the target <NUM>.

The first inlet <NUM> extends from the capture cavity <NUM> to a surface of the sample capture cell <NUM> defining the front end region. Accordingly, the first inlet <NUM> is configured to transmit a primary flow <NUM> of the carrier gas from a first location adjacent to the front end region of the sample capture cell <NUM> into a first region <NUM> of the capture cavity <NUM>, which is adjacent to the first inlet <NUM>. A more detailed rendering of the flow of carrier gas through the first inlet <NUM> into the first region <NUM> of the capture cavity <NUM> is exemplarily and schematically illustrated in <FIG>. In the illustrated embodiment, the first inlet <NUM> extends vertically from the lower surface <NUM> toward the upper surface <NUM> to a height, h1 (see, e.g., <FIG>), of <NUM> (or thereabout), and extends horizontally between the lower surface <NUM> and upper surface <NUM> across a width, w (see, e.g., <FIG>), of <NUM> (or thereabout). It will be appreciated, however, that depending on factors such as the carrier gas flow velocity within a region of the interior <NUM> at the first location, the size and shape of any portion of the first inlet <NUM> (e.g., from the surface of the sample capture cell <NUM> defining the front end region to the capture cavity <NUM>) may be modified in any suitable or beneficial manner. Constructed as exemplarily described above, the first inlet <NUM> is configured to transmit the primary flow <NUM> into the first region <NUM> of the capture cavity <NUM> along a first direction that is generally (or at least substantially) parallel to a surface of the target <NUM>. Although, in the illustrated embodiment, the first inlet <NUM> extends from the lower surface <NUM> toward the upper surface <NUM>, it will be appreciated that, in other embodiments, the first inlet <NUM> may be spaced apart from the lower surface <NUM>. Although, in the illustrated embodiment, dimensions (e.g., height and width dimensions) of the first inlet <NUM> are illustrated as being the same as those of the capture cavity <NUM> at the first region <NUM>, it will be appreciated that, in other embodiments, dimensions (e.g., height and width dimensions) of the first inlet <NUM> may be different from those of the capture cavity <NUM> at the first region <NUM>.

The second inlet <NUM> extends from the capture cavity <NUM> to the upper surface <NUM> of the sample capture cell <NUM>. Accordingly, the second inlet <NUM> is configured to transmit a secondary flow <NUM> of the carrier gas from a second location, adjacent to the upper surface <NUM> of the sample capture cell <NUM>, into a second region <NUM> of the capture cavity <NUM>. A more detailed rendering of the flow of carrier gas through the second inlet <NUM> into the second region <NUM> of the capture cavity <NUM> is exemplarily and schematically illustrated in <FIG>. In the illustrated embodiment, the second inlet is a configured as a circular tube having a diameter in a range from <NUM> to <NUM> (or thereabout), aligned with and extending along the optical path <NUM> from the capture cavity <NUM> to the upper surface <NUM> so as to a height, h2 (see, e.g., <FIG>), of <NUM> (or thereabout). It will be appreciated, however, that depending on factors such as the carrier gas flow velocity within the interior <NUM> at the second location, the size and shape of any portion of the second inlet <NUM> (e.g., from the upper surface <NUM> of the sample capture cell to the capture cavity <NUM>) may be modified in any suitable or beneficial manner.

As best shown in <FIG> and <FIG>, a transition region of a wall extending from the upper surface <NUM> into the second inlet <NUM> is rounded or chamfered. By providing a rounded or chamfered transition region, the turbulence of the flow of carrier gas entering into the second inlet <NUM> can be controlled to be suitably or beneficially small. In one embodiment, the round or chamfer of the transition region may have a radius of <NUM>, or thereabout. Thus, the second inlet <NUM> may have a relatively large first diameter at the upper surface <NUM> and a relatively small second diameter at a location below the transition region (e.g., <NUM>, or thereabout). It will be appreciated, however, that depending on factors such as the carrier gas flow velocity within a region of the interior <NUM> over the upper surface <NUM> of the sample capture cell <NUM>, the radius of the transition region can be significantly more or less than <NUM>.

Constructed as exemplarily described above, the second inlet <NUM> is configured to transmit the flow of the carrier gas into the second region <NUM> of the capture cavity <NUM> along a second direction that is generally (or at least substantially) perpendicular to a surface of the target <NUM>. In another embodiment, however, the second inlet <NUM> may be configured to transmit the flow of the carrier gas into the second region <NUM> of the capture cavity <NUM> along a second direction that is substantially oblique to a surface of the target <NUM>. Further, and as best shown in <FIG>, the second inlet <NUM> is configured such that the sample generator <NUM> is in optical communication with a region of the target <NUM> (e.g., along the optical path <NUM>) through the second inlet <NUM> and the capture cavity <NUM>. Accordingly, laser light <NUM> may be directed from the sample generator <NUM> along the optical path <NUM>, through the second inlet <NUM> and the capture cavity <NUM> to impinge upon the target <NUM> at a laser ablation site. When the directed laser light <NUM> impinges the target <NUM> at the laser ablation site, a plume <NUM> containing the target material ejected or otherwise generated from the target <NUM>.

Depending on factors such as the material of the target <NUM>, characteristics of the directed laser light <NUM>, the velocity of the carrier gas flow, etc., vertical expansion of the plume may occur very rapidly. For example, the plume may extend to a height, h3 (see, e.g., <FIG>) above the target <NUM> of about <NUM> within less than <NUM> (e.g., about <NUM>) after the directed laser light <NUM> impinges the target <NUM> at the laser ablation site. By transmitting a flow of the carrier gas through the second inlet into the third region via along the second direction, the vertical expansion of the plume may be prevented or otherwise minimally re-entrained, thereby reducing or minimizing the volume that the plume of target material would otherwise occupy within the capture cavity <NUM>. By reducing or minimizing the volume that the plume of target material occupies within the capture cavity <NUM>, target material within the can be efficiently captured and transferred into the outlet <NUM>, as will be described in greater detail below.

The outlet <NUM> extends from a surface of the sample capture cell <NUM> defining the back end region to a region of the guide wall <NUM> exposed within the capture cavity <NUM>. Accordingly, the outlet <NUM> is configured to receive carrier gas from a third region <NUM> of the capture cavity <NUM> so that the received carrier gas can be transmitted to a location outside the sample capture cell <NUM> (e.g., via the transport conduit <NUM>). In the illustrated embodiment, the outlet <NUM> includes a first bore <NUM> having an inlet arranged at the third region <NUM> of the capture cavity <NUM>, and a second bore <NUM> axially aligned with the first bore <NUM> and extending from the first bore <NUM> to the surface of the sample capture cell <NUM> defining the back end region. The first bore <NUM> and the second bore <NUM> are generally configured to accommodate a portion of the transport conduit <NUM>. In the illustrated embodiment, the first bore <NUM> has a circular cross-section with a first diameter and the second bore <NUM> has a circular cross-section with a second diameter larger than the first diameter to additionally accommodate an outlet conduit seal <NUM>. The first diameter may be equal to or slightly larger than the outer diameter of the transport conduit <NUM> (e.g., so that the transport conduit <NUM> may be inserted into the first bore <NUM>), or may be less than or equal to the inner diameter of the transport conduit <NUM>. In one embodiment, the first bore <NUM> may have a first diameter in a range from <NUM> (or thereabout).

As best shown in <FIG> and <FIG>, a transition region of a wall extending from the guide wall <NUM> into the outlet <NUM> is rounded or chamfered. By providing a rounded or chamfered transition region, the turbulence of the flow of carrier gas entering into the outlet <NUM> can be controlled to be suitably or beneficially small. In one embodiment, the round or chamfer of the transition region may have a radius of <NUM>, or thereabout. Thus, the outlet <NUM> may have a relatively large diameter at the inlet of the first bore <NUM> (i.e., at the guide wall <NUM>) (e.g., <NUM>, or thereabout) and a relatively small diameter at a location within an intermediate region of the first bore <NUM> (e.g., corresponding to the aforementioned first diameter of the first bore <NUM>). It will be appreciated, however, that depending on factors such as the carrier gas flow velocity within the third region <NUM> of the capture cavity <NUM>, the radius of the transition region can be significantly more or less than <NUM>.

The guide wall <NUM> is configured to deflect, vector or otherwise direct one or more flows of the carrier gas introduced into the capture cavity <NUM> (e.g., via one or more of the opening <NUM>, the first inlet <NUM> and the second inlet <NUM>) such that at least a portion of the plume of target material received within the capture cavity <NUM> through the opening <NUM> are entrained by the directed flow of carrier gas, thereby so as to be transferrable into the outlet <NUM> (see, e.g., <FIG>). For purposes of discussion herein, target material transferred into the outlet <NUM> is "captured" by the sample capture cell <NUM> and, therefore, may also be referred to as a "sample" of the target <NUM> or as a "target sample". In one embodiment, the guide wall <NUM> is configured to direct the one or more flows of the carrier gas such that the flow of carrier gas into the plume <NUM> or into the outlet <NUM> is laminar or quasi-laminar. In another embodiment, however, the guide wall <NUM> is configured to direct the one or more flows of the carrier gas such that the flow of carrier gas into the plume <NUM> or into the outlet <NUM> is turbulent. Similarly, one or more of the aforementioned features of the sample capture cell <NUM> (e.g., the lower surface <NUM>, the guide wall <NUM>, the opening <NUM>, the first inlet <NUM>, the second inlet <NUM>, or the like) may be configured such the flow of carrier gas over the surface of the target <NUM> and outside the capture cavity <NUM> is laminar, quasi-laminar, turbulent or a combination thereof.

As best shown in <FIG>, the guide wall <NUM> is configured such that the inlet of the first bore <NUM> is recessed relative to a surface defining the front end region of the sample capture cell <NUM> by a distance of <NUM> (or thereabout). It will be appreciated, however, that depending on factors such as the carrier gas flow velocity within the capture cavity <NUM> and the location and orientation of the second inlet <NUM> within the sample capture cell <NUM>, the distance by which the inlet of the first bore <NUM> is recessed relative to a surface defining the front end region of the sample capture cell <NUM> can be significantly more or less than <NUM>. As best shown in <FIG>, the guide wall <NUM> is configured so as to be curved in a region adjacent to the inlet of the first bore <NUM> (e.g., circularly curved, centered on an axis of the second inlet <NUM> with a radius in a range from <NUM> to <NUM>, or thereabout). It will be appreciated, however, that depending on factors such as the carrier gas flow velocity and direction within the capture cavity <NUM> and the location and orientation of the second inlet <NUM> within the sample capture cell <NUM>, the geometric configuration may be varied in any manner that may be suitable or beneficial.

If the sample capture cell <NUM> is coupled to the transport conduit, the sample transferred into the outlet <NUM> can be transported to a location outside the sample capture cell <NUM> (e.g., via the transport conduit <NUM>). To couple the transport conduit <NUM> to the sample capture cell <NUM>, an end of the transport conduit <NUM> (also referred to as a "first end" or a "sample receiving end") is inserted into the second bore <NUM> and through the outlet conduit seal <NUM>. Optionally, and depending upon the diameter of the first bore <NUM>, the transport conduit <NUM> may be further inserted into the first bore <NUM>. In one embodiment, the transport conduit <NUM> is inserted into the first bore <NUM> such that the sample receiving end is recessed within the first bore <NUM>. For example, the sample receiving end can recessed within the first bore <NUM> to be spaced apart from the inlet of the first bore <NUM> by a distance in a range from <NUM> to <NUM> (or thereabout). In other embodiments, however, the transport conduit <NUM> is inserted into the first bore <NUM> such that the sample receiving end is recessed flush with, or extends beyond, the inlet of the first bore <NUM>. Upon coupling the transport conduit <NUM> to the sample capture cell <NUM> in the manner described above, the carrier gas received at the outlet can also be received within the transport conduit <NUM> and transported to a location outside the sample chamber <NUM> (e.g., to the sample preparation system <NUM>).

In addition to the sample receiving end, the transport conduit <NUM> may further include a second end (also referred to herein as a sample injection end) that is opposite the sample receiving end. Generally, the transport conduit <NUM> is at least substantially straight from the sample receiving end to the sample injection end, with a length (defined from the sample receiving end to the sample injection end) in a range from <NUM> to <NUM> (e.g., in a range from <NUM> to <NUM>, or in a range from <NUM> to <NUM>, or in a range from <NUM> to <NUM>, or in a range from <NUM> to <NUM>, or thereabout) and an inner diameter in a range from <NUM> to <NUM> (e.g., in a range from <NUM> to <NUM>, or <NUM>, or thereabout). It will be appreciated, however, that depending on factors such as the pressure within the interior <NUM>, the inner diameter of the transport conduit <NUM>, the configuration of the sample chamber <NUM> and the sample preparation system <NUM>, the length of the transport conduit <NUM> may be less than <NUM> or greater than <NUM>. Similarly, depending on factors such as the pressure within the interior <NUM> and the length of the transport conduit <NUM>, the inner diameter of the transport conduit <NUM> may be less than <NUM> or greater than <NUM>. The inner diameter of the transport conduit <NUM> at the sample receiving end may be same or different (i.e., larger or smaller) than the inner diameter of the transport conduit <NUM> at the sample injection end. Further, the inner diameter of the transport conduit <NUM> may be at least substantially constant along the length thereof, or may vary. In one embodiment, the transport conduit <NUM> is provided as a single, substantially rigid tube having no valves between the sample receiving end and sample injection end. Exemplary materials from which the transport conduit <NUM> can be formed include one or more materials selected from the group consisting of a glass, a polymer, a ceramic and a metal. In one embodiment, however, the transport conduit <NUM> is formed of fused glass. In another embodiment, the transport conduit <NUM> is formed of a polymer material such as a fluoropolymer (e.g., perfluoroalkoxy, polytetrafluoroethylene, or the like or a combination thereof), polyethylene terephthalate, or the like or a combination thereof. In yet another embodiment, the transport conduit <NUM> is formed of a ceramic material such as alumina, sapphire, or the like or a combination thereof. In still another embodiment, the transport conduit <NUM> is formed of a metal material such as stainless steel, copper, platinum, or the like or a combination thereof.

Constructed as exemplarily described above, the transport conduit <NUM> can efficiently transport a sample from the sample capture cell <NUM> to the sample preparation system <NUM>. Efficient capture and transfer of a sample from a laser ablation site to the transport conduit <NUM>, coupled with efficient transport of the sample from the sample capture cell <NUM> to the sample preparation system <NUM>, can enable the analysis system <NUM> to generate signals (e.g., corresponding to the composition of target sample) that have relatively short peak widths (e.g., in a range from about <NUM> to about <NUM> (e.g., <NUM>, or thereabout), measured relative to a baseline where <NUM>% of the total signal is observed within <NUM>) and correspondingly fast wash-out times. Generating signals having such relatively short peak widths and fast wash-out times, can help to facilitate high-speed and high sensitivity compositional analysis of the target <NUM>. Similarly, depending on factors such as the pressure within the interior <NUM> and the length of the transport conduit <NUM>, the inner diameter of the transport conduit <NUM>, the peak width may be beneficially increased to <NUM> or thereabout.

<FIG> is a cross-sectional view schematically illustrating the sample capture cell shown in <FIG> incorporating an auxiliary inlet, according to another embodiment.

Referring to <FIG>, the aforementioned sample capture cell may further include an auxiliary inlet, such as auxiliary inlet <NUM>, extending from the capture cavity <NUM> to the upper surface <NUM> of the sample capture cell <NUM>. Accordingly, the auxiliary inlet <NUM> is configured to transmit an auxiliary flow <NUM> of the carrier gas from a third location, adjacent to the upper surface <NUM> of the sample capture cell <NUM>, into a fourth region <NUM> of the capture cavity <NUM>. Upon being introduced into the fourth region <NUM>, the auxiliary flow <NUM> may mix with the directed flow(s) of carrier gas present within the capture cavity <NUM> and, thereafter, transferred into the outlet <NUM>. In the illustrated embodiment, the fourth region <NUM> is closer to the first region <NUM> than the third region <NUM>. In other embodiments, however, the fourth region <NUM> may be closer to the third region <NUM> than the first region <NUM>, or may be equidistant between the first region <NUM> and the third region <NUM>.

In the illustrated embodiment, the auxiliary inlet is configured as a circular tube having a diameter equal to or different from (e.g., larger than or smaller than) the diameter of the second inlet. It will be appreciated, however, that depending on factors such as the carrier gas flow velocity within the interior <NUM> at the second location, the size and shape of any portion of the auxiliary inlet <NUM> (e.g., from the upper surface <NUM> of the sample capture cell to the capture cavity <NUM>) may be modified in any suitable or beneficial manner. Although not illustrated, the auxiliary inlet may include a wall having a transition region extending from the upper surface <NUM> into the auxiliary inlet <NUM> and configured in the manner discussed above with respect to the second inlet <NUM>. Constructed as exemplarily described above, the auxiliary inlet <NUM> is configured to transmit the auxiliary flow <NUM> into the fourth region <NUM> of the capture cavity <NUM> along a third direction that is for example, different from the aforementioned first direction and second direction. In one embodiment, the third direction may be substantially oblique, at least substantially parallel or at least substantially perpendicular to the surface of the target <NUM> when the sample capture cell <NUM> is operably proximate to the target <NUM>.

Although the auxiliary inlet <NUM> is illustrated as being integrally formed within the body of the sample capture cell <NUM>, it will be appreciated that the auxiliary inlet <NUM> may be separately formed from a different component, which is subsequently coupled to the body of the sample capture cell <NUM>. Further, although the auxiliary inlet <NUM> is illustrated as transmitting the auxiliary flow <NUM> of carrier gas into the fourth region <NUM> of the capture cavity <NUM>, the auxiliary inlet <NUM> may be positioned, oriented or otherwise configured to transmit the auxiliary flow <NUM> of carrier gas into the first region <NUM>, the third region <NUM>, or the second region <NUM> (e.g., the auxiliary inlet <NUM> may extend to the second inlet <NUM>). In the illustrated embodiment, the auxiliary inlet <NUM> is configured to transmit the auxiliary flow <NUM> of carrier gas into the capture cavity <NUM> along a third direction that extends toward the outlet <NUM> and the target <NUM>. In other embodiments, however, the third direction may extend toward the outlet <NUM> and away from the target <NUM>, toward the first inlet <NUM> and the target <NUM>, toward the first inlet <NUM> and away from the target <NUM>, or the like or a combination thereof.

Although the auxiliary inlet <NUM> is described above as being configured to transmit the auxiliary flow <NUM> of carrier gas from the third location adjacent to the upper surface <NUM> of the sample capture cell <NUM> into the capture cavity <NUM>, it will be appreciated that the auxiliary inlet <NUM> may be configured to transmit a flow of the carrier gas from any location adjacent to any surface of the sample capture cell <NUM>. Moreover, although the auxiliary inlet <NUM> is described above as being configured to transmit a flow of carrier gas into the capture cavity <NUM>, it will be appreciated that the sample capture cell <NUM> may be configured such that the auxiliary inlet <NUM> can be coupled to an external auxiliary fluid source (e.g., containing a fluid such as helium gas, argon gas, nitrogen gas, water vapor, atomized or nebulized fluids, atomized or nebulized solvents, discrete droplets containing microparticles, nanoparticles, or biological samples such as cells, or the like, or a combination thereof). In such a configuration, the auxiliary inlet <NUM> may transmit a fluid that is different from the carrier gas into the capture cavity <NUM>, or may transmit an auxiliary flow of the carrier gas into the capture cavity <NUM>, the auxiliary flow having a different characteristic (e.g., a different temperature, a different flow rate, etc.) from the carrier gas flow generated by the one or more injection nozzles <NUM>. It will be appreciated that any fluid introduced into the capture cavity <NUM> by the auxiliary inlet <NUM> may mix with the directed flow(s) of carrier gas present within the capture cavity <NUM> and, thereafter, transferred into the outlet <NUM>. In one embodiment, when coupled to an auxiliary fluid source, the auxiliary inlet <NUM> may transmit one or more fluids such as nitrogen gas or water vapor to facilitate sample counting, laser ablation standardization, calibration, or the like or a combination thereof.

<FIG> is a cross-sectional view schematically illustrating one embodiment of an injector coupled to a sample preparation system, and a portion of an analysis system.

In the embodiment exemplarily illustrated in <FIG>, the sample preparation system <NUM> may be provided as an ICP torch <NUM> including an outer tube <NUM> (also referred to herein as a "confinement tube <NUM>") enclosing a space <NUM> where a plasma can be generated, an inner tube <NUM> (also referred to herein as a "plasma gas tube <NUM>") arranged within the confinement tube <NUM>, coaxial with an injection axis <NUM> of the confinement tube <NUM>, and a coil <NUM> configured to ionize gas within the space <NUM> to generate a plasma <NUM> (e.g., occupying the darkly-shaded region within the space <NUM>) when energized by an RF source (not shown). Although the sample preparation system <NUM> is illustrated as including a coil <NUM>, it will be appreciated that the sample preparation system <NUM> may alternatively or additionally include ionization mechanisms of other configurations. For example, a set (e.g., a pair) of flat plates may be disposed outside the confinement tube <NUM> to ionize the plasma gas within the space <NUM> to generate the plasma.

In the illustrated embodiment, the confinement tube <NUM> and the plasma gas tube <NUM> are spaced apart from each other to define an annular outer gas transmission conduit <NUM> (also referred to as a "coolant gas transmission conduit") that may be coupled to a gas source (e.g., a reservoir of pressurized gas, not shown) to receive an outer flow <NUM> (also referred to as a "coolant flow") of gas (e.g., argon gas) and transmit the received outer flow <NUM> of gas into the space <NUM> (e.g., at a flow rate in a range from <NUM>/min to <NUM>/min, or thereabout). Gas introduced into the space <NUM> via the outer flow <NUM> can be ionized to form the aforementioned plasma <NUM>. Generally, plasma <NUM> generated has a power of about <NUM> kW or less. In one embodiment, however, the plasma <NUM> generated can have a power higher than <NUM> kW (e.g., sufficient to melt the confinement tube <NUM>). In such an embodiment, the gas introduced into the space <NUM> via the outer flow <NUM> can also be used to cool the confinement tube <NUM>, preventing the confinement tube <NUM> from melting.

Optionally, the plasma gas tube <NUM> may be coupled to an auxiliary gas source (e.g., a reservoir of pressurized gas, not shown) to receive an intermediate flow <NUM> (also referred to as an "auxiliary flow") of gas (e.g., argon gas) and transmit the received intermediate flow <NUM> of gas into the space <NUM> (e.g. at a flow rate in a range from <NUM>/min to <NUM>/min). Gas introduced into the space <NUM> via the intermediate flow <NUM> can be used to adjust the position the base of the plasma <NUM> along the injection axis <NUM> relative to the confinement tube <NUM>.

A portion of the plasma <NUM> generated within the space <NUM> is then transferred into the analysis system <NUM> (e.g., an MS system) by passing sequentially through an interface (e.g., an interface including a sampling cone <NUM> and a skimmer cone <NUM>) of the analysis system <NUM>. Although the analysis system <NUM> is illustrated as having an interface with the sampling cone <NUM> and the skimmer cone <NUM>, it will be appreciated that the interface may be differently configured in any manner suitable or beneficial manner. If the aforementioned target material generated within the sample chamber <NUM> is introduced in the plasma generated within the space <NUM>, then the target material may transferred into the analysis system <NUM> for compositional analysis.

To facilitate introduction of the sample through the transport conduit <NUM> into a sample preparation system such as sample preparation system <NUM>, the apparatus <NUM> may include an injector, such as injector <NUM>. The injector <NUM> may be detachably coupled to, or otherwise arranged operably proximate to, the sample preparation system <NUM> by any suitable or beneficial mechanism. In the illustrated embodiment, the injector <NUM> may include an outer conduit <NUM> having a fluid injection end <NUM>, and the aforementioned transport conduit <NUM>.

Generally, the outer conduit <NUM> is arranged within the plasma gas tube <NUM>, coaxial with the injection axis <NUM> and is configured to be coupled to a fluid source (e.g., one or more reservoirs of pressurized gas, not shown) to receive an outer injector flow <NUM> of a fluid (e.g., argon gas). Fluid within the outer injector flow <NUM> is injectable into the space <NUM> through a fluid injection end <NUM> of the outer conduit <NUM>. Generally, the inner diameter of the outer conduit <NUM> at the fluid injection end <NUM> is in a range from <NUM> to <NUM> (e.g., <NUM>, or thereabout). Upon injecting the fluid into the space <NUM> from the fluid injection end <NUM>, a central channel <NUM> (e.g., occupying the lightly-shaded region within the space <NUM>) can be formed within or "punched through" the plasma <NUM>. Further, fluid injected into the space <NUM> through the fluid injection end <NUM> tends to generate a first zone <NUM> relatively close to the fluid injection end <NUM>, which is characterized by a relatively high turbulence of fluid (e.g., including fluid from the outer injector flow <NUM> and possibly gas from the intermediate flow <NUM>). Turbulence quickly decreases along the injection axis <NUM> with increasing distance from the fluid injection end <NUM> into the plasma <NUM>. Accordingly, a second zone relatively distant from the fluid injection end <NUM> along the injection axis <NUM> and located within the central channel <NUM>, can be characterized by a relatively low turbulence of fluid (e.g., including fluid from the outer injector flow <NUM> and possibly gas from the intermediate flow <NUM>).

Generally, the transport conduit <NUM> configured to direct a carrier flow <NUM> containing the aforementioned target sample, along with any other fluids that carry the sample through the transport conduit <NUM> (e.g., the aforementioned carrier gas, any fluid introduced into the capture cavity <NUM> by the auxiliary inlet <NUM>, or the like or a combination thereof) through the aforementioned sample injection end (indicated at <NUM>). When directed through transport conduit <NUM> and past the sample injection end <NUM>, the carrier flow <NUM> (and, thus, the sample contained therein) is injectable into the space <NUM> (e.g., along the injection axis <NUM>), where it can be ionized and subsequently transferred to the analysis system <NUM>.

In one embodiment, the transport conduit <NUM> may be arranged within the outer conduit <NUM>, coaxial with the injection axis <NUM>, such that the sample injection end <NUM> is locatable within the outer conduit <NUM>, locatable outside the outer conduit <NUM>, or a combination thereof. For example, the transport conduit <NUM> may be arranged within the outer conduit <NUM> such that the sample injection end <NUM> is located within the outer conduit <NUM>, and is spaced away from the fluid injection end <NUM> by a distance in a range from <NUM> to <NUM>. In another example, transport conduit <NUM> may be arranged within the outer conduit <NUM> such that the sample injection end <NUM> is located outside the outer conduit <NUM>, and is spaced away from the fluid injection end <NUM> by a distance in a range from greater than <NUM> to <NUM> (e.g., by a distance in a range from <NUM> to <NUM>, or by a distance in a range from <NUM> to <NUM>, or by a distance in a range from <NUM> to <NUM>, or by a distance of <NUM>, or thereabout). Depending on factors such as the configuration of the outer conduit <NUM>, the flow rate of the outer injector flow <NUM> exiting the outer conduit <NUM>, and the configuration of the sample preparation system <NUM>, it will be appreciated that the sample injection end <NUM> may be located within the outer conduit <NUM> and spaced away from the fluid injection end <NUM> by a distance greater than <NUM> (or may be located outside the outer conduit <NUM> and spaced away from the fluid injection end <NUM> by a distance greater than <NUM>). The position of the transport conduit <NUM> may be fixed relative to the outer conduit <NUM>, or may be adjustable.

In one embodiment, the relative position of the sample injection end <NUM> may be selected or otherwise adjusted to be positioned at a location (e.g., within the space <NUM>) characterized by a fluid turbulence which is less that associated with the aforementioned first zone <NUM>. For example, the sample injection end <NUM> may be positioned to be disposed within the aforementioned second zone. When the carrier flow <NUM> is injected from the sample injection end <NUM> when located within the second zone, lateral diffusion of the ionized target sample within the central channel <NUM> of the plasma <NUM> can be reduced significantly compared to the central channel <NUM> (e.g., as indicated by the relatively focused beam <NUM> of the ionized target sample). As a result, the beam <NUM> can be kept at least substantially on-axis relative to the interface of the analysis system <NUM> to enhance the sampling efficiency obtainable by the analysis system <NUM> and the sensitivity of the analysis system <NUM>.

In one embodiment, the injector <NUM> may include a centering member <NUM> configured to maintain the radial position of the transport conduit <NUM> within the outer conduit <NUM>. As exemplarily illustrated, the centering member <NUM> may be disposed within the outer conduit <NUM> and include a central bore <NUM> though which the transport conduit <NUM> can be inserted and a plurality of peripheral bores <NUM> disposed radially and circumferentially about the central bore <NUM> to permit transmission of the outer injector flow <NUM> from the aforementioned fluid source to the fluid injection end <NUM>. In one embodiment, the injector <NUM> may further include a conduit guide <NUM> configured to help guide insertion of the transport conduit <NUM> into the centering member <NUM> from a location outside the injector <NUM>.

Constructed as exemplarily described above, the outer conduit <NUM> of the injector <NUM> may have the same primary function as a conventional ICP torch injector, in that it provides a fluid flow (e.g., Ar, or admixtures thereof with helium gas or nitrogen gas), that establishes the central channel of the plasma <NUM> into which the sample is introduced. In the injector <NUM> described above, the transport conduit <NUM> need not be coupled to the sample capture cell <NUM> as described above. In other such embodiments, the transport conduit <NUM> may alternatively or additionally be used to introduce a standard (e.g., to enable optimization of instrumental parameters, to enable calibration, etc.) into the analysis system <NUM> via a sample preparation system such as the sample preparation system <NUM>, or the like. Such a standard could be introduced as an aerosol or dried aerosol (e.g. from a nebuliser, or as discrete droplets from a droplet generator, or as a gas or vapor generated by chemical or thermal means, etc.). The standard could even be an aerosol from a sample chamber other than the sample chamber <NUM>. In other such embodiments, the transport conduit <NUM> may alternatively or additionally be used to introduce additional gases into the sample preparation system <NUM> (e.g. helium gas, nitrogen gas, water vapor derived for example from thermal vaporization or a nebulizer or droplet generator, etc.).

In one embodiment, the sample chamber <NUM> may be substituted or used in conjunction with a discrete droplet generator (e.g., derived from piezoelectric or thermal inkjet technologies, although any source of discrete droplets capable of delivering particles of less than <NUM>, or thereabout, to the sample preparation system <NUM> would work). In some applications, a continuous source of droplets, such as from a nebulizer, or continuous flow of vapor (e.g., water vapor). In such embodiments, the droplet generators may be coupled to a desolvation stage to carry out prior evaporation (which may be complete or partial) of the droplets. Droplet/desolvation technologies are well known and widely published.

In one embodiment, the droplet generator and accompanying desolvation unit may include two modes of operation. In a first mode of operation, the droplet generator and accompanying desolvation unit may replace the sample chamber <NUM> as the sample source, in which case a sample may be introduced directly into the transport conduit <NUM> of the injector <NUM> as a sequence of discrete droplets having diameters in the low or sub-micron range (after desolvation). These droplets may contain variously, for example, liquid samples, liquid droplets containing biological samples such as single cells, or micro or nano-particles. In a second mode of operation, the droplet generator and accompanying desolvation unit may run simultaneously and in synchronicity with the sample generator <NUM> and sample chamber <NUM> so that the liquid droplets can be introduced into the transport conduit simultaneously with the aerosol containing the target material, or sequentially in single or multiple events alternated with the aerosol containing the target material. This second mode of operation provides a mechanism for calibration (e.g., if the droplets contain standards), a mechanism for control of plasma conditions (e.g., if the droplets contain a solvent), or a mechanism for a quasi-continuous signal output that can be used for optimisation of instrumental parameters.

<FIG> is a partial cross-sectional view schematically illustrating one embodiment of a desolvation unit coupled between a droplet generator and an injector such as the injector shown in <FIG>.

Referring to <FIG>, the desolvation unit may include an adaptor <NUM> configured to receive a flow of droplets and/or vapor (e.g., as indicated at <NUM>) and one or more desolvator gas flows (e.g., as indicated at <NUM>) where the received droplet(s), vapor(s) and other gas flows can be mixed and thereafter be transported (e.g., vertically downwardly under the influence of gravity/and or the desolvating gas flow) through a tube <NUM> (e.g., a stainless steel tube) into a first inlet of an adaptor coupling <NUM>, which may further include a second inlet configured to receive a flow of a make-up fluid (e.g., as indicated at <NUM>). Within the adaptor coupling <NUM>, the mixed droplet(s), vapor(s) and other gas flows are entrained by the flow of make-up fluid, transported through a tapered reducer <NUM> and into the transport conduit <NUM> and, thereafter, into the aforementioned injector <NUM>. It will be appreciated that the taper provided by the tapered reducer <NUM> can be made sufficiently gradual to avoid introducing undesirable turbulence and particle loss.

Constructed as described above, the illustrated droplet generator and associated desolvation unit replace the sample chamber <NUM> and sample capture cell <NUM> discussed above. In another embodiment, however, the illustrated droplet generator and associated desolvation unit may be placed in-line with the sample chamber <NUM> and/or sample capture cell <NUM>. In such an embodiment, an opening may be formed in the transport conduit <NUM> at a location between the sample receiving end (which is disposed within the sample chamber <NUM>, coupled to the sample capture cell <NUM>) and the sample injecting end <NUM> (which is disposed within the injector <NUM>), and the adaptor coupling <NUM> may be coupled to the transport conduit <NUM> to place the tube <NUM> in fluid communication with the interior of the transport conduit <NUM>.

Claim 1:
An apparatus (<NUM>) for handling target material removed from a laser ablation site of a target, the apparatus comprising:
a sample capture cell (<NUM>) including:
a capture cavity (<NUM>) having an opening (<NUM>) formed in a surface at a first region (<NUM>) of the capture cell, wherein the capture cavity is configured to receive, through the opening, target material ejected or generated from the laser ablation site when the surface faces toward the target and the sample capture cell is spaced apart from the target by a distance of <NUM> or less;
a first inlet (<NUM>) extending from the capture cavity to an exterior of the sample capture cell defining a front end region, wherein the first inlet is configured to transmit a flow of a carrier gas along a first direction at least substantially parallel to the surface of the target from a first location adjacent to the exterior of the sample capture cell into the capture cavity;
an outlet (<NUM>) in fluid communication with the capture cavity and configured to receive, from the capture cavity, the carrier gas and at least a portion of the removed target material;
a second inlet (<NUM>) extending from the capture cavity to an upper surface of the exterior of the sample capture cell, wherein the second inlet is configured to transmit a second flow of the carrier gas along a second direction perpendicular to the first direction from a second location adjacent to the exterior of the capture cell into the capture cavity, wherein the second inlet and the capture cavity are configured such that laser light (<NUM>) is transmittable through the second inlet and the capture cavity and onto a region of the target when the sample capture cell is spaced apart from the target by a distance of <NUM> or less; and
a guide wall (<NUM>) exposed within the capture cavity and configured to direct a flow of the carrier gas within the capture cavity between the first inlet and the outlet such that at least a portion of the target material received within the capture cavity are transferrable into the outlet as a sample.