Laser Ablation Cell

Abstract

It aims to suppress convection within the cell and improve the flow rate of the carrier gas. [Solution] The present invention is a cell for laser ablation comprising a cell body 2, a port block 3A connected to the carrier gas inlet side of the cell body, a port block 3B connected to the carrier gas outlet side of the cell body, and a slit member 13 interposed between the connection end of the cell body 2 and the port block 3A, wherein the slit member 13 controls the amount of carrier gas introduced into the cell body 2 by blocking a portion of the inlet of the port block 3A.

Description

[Technical field]

[0001] The present invention relates to a cell for laser ablation. [Background technology]

[0002] Conventionally, in elemental analysis by laser ablation (so-called LA-ICP-MS), the surface of the object to be measured is irradiated with a laser to turn the object into an aerosol (particulate).The aerosol (particles) are introduced into an analytical device such as an ICP-MS or ICP-OES in the downstream stage to perform elemental analysis.

[0003] The inlet of these analytical instruments such as ICP-MS and ICP-OES generates plasma in a gas atmosphere. Therefore, in order to irradiate the target with a laser and transport the aerosol (particles) directly to the analytical instrument, a cell is required to create a gas atmosphere on the irradiated surface. In addition, to transport the aerosol, gas flows from the cell inlet through the outlet to the analytical instrument.

[0004] At this time, the upper limit of the gas flow rate is limited by the limit on the analytical device side, so the flow rate in the cell does not increase sufficiently, and gas convection occurs around the sample, which may affect the accuracy depending on the installation location of the measurement target. For example, FIG. 10 shows the state of convection in the vertical direction in a cell according to the conventional technology, and FIG. 11 shows the state of convection in the depth direction in a cell according to the conventional technology. In the cell 100 shown in FIG. 10 and FIG. 11, port blocks 101A and 101B are connected to the inlet side and outlet side of the cell body 102, respectively, the upper surface of the cell body 102 is opened, and the window portion 106 is fixed by a cover member 105. A sample stage 103 is placed in the recess 102A of the cell body 102, and a sample 104 to be measured is placed on it. The carrier gas introduced from the inlet path 101A-1 of the port block 101A is led into the inside of the cell body 2, and the aerosol is led out via the outlet path 101B-1. The discharged carrier gas convects in the vertical direction as indicated by reference symbol T1 in FIG. 10, and convects in the depth direction as indicated by reference symbols T2 and T3 in FIG.

[0005] When performing two-dimensional or three-dimensional distribution (imaging) analysis, the flow rate within the cell cannot be increased, so in order to increase the spatial resolution, it is necessary to leave a sufficient amount of time between laser irradiation of adjacent locations, which has the disadvantage of long measurement times (if the interval is too short, the aerosol will mix with the aerosol from the previous stage).

[0006] For example, Figure 10 also shows the flow of aerosols when performing two-dimensional or three-dimensional distribution analysis. In the figure, when a point on the left side is irradiated with a laser, the aerosol flows into the analysis device (symbol U1). The aerosol flows into this analysis device, and when the analysis is complete, the next point is irradiated with a laser, and the aerosol flows into the analysis device (symbol U2). By repeating this process, the distribution status can be analyzed. For this reason, in order to further improve spatial resolution and shorten measurement time, conventional technology has devised a way to increase the flow rate within the cell by using a separate cell with a small cell volume.

[0007] Here, Patent Document 1 discloses a laser ablation mass spectrometer that includes a sample stage, a laser irradiation unit, an airflow transport system, an ion source, and an analysis unit. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2008-191134 A Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the conventional techniques such as Patent Document 1, it was not possible to control the convection within the cell or the flow rate of the carrier gas within the cell on the cell side.

[0010] The present invention has been made in view of the above problems, and an object of the present invention is to suppress convection within a cell and improve the flow rate of the carrier gas. [Means for solving the problem]

[0011] In order to solve the above problems, a cell for laser ablation according to one aspect of the present invention includes a cell body, an inlet part connected to a carrier gas inlet side of the cell body, an outlet part connected to a carrier gas outlet side of the cell body, and a slit member interposed between the connection end of the cell body and the inlet part, and the slit member controls the amount of the carrier gas introduced into the cell body by blocking a part of the inlet port of the inlet part. The slit member is attached to the introduction portion, and the size of the shielding is adjusted by adjusting the attachment position to the introduction portion in the height direction.

[0012] A cell for laser ablation according to another aspect of the present invention comprises: With an opening at the top A cell body; A window portion disposed in the opening portion, and a mounting stand disposed on the cell body; An inlet part connected to the inlet side of the carrier gas of the cell body, an outlet part connected to the outlet side of the carrier gas of the cell body, and so as to face the installation table without changing the positional relationship between the window portion and the installation table. Inserted A hole is provided in the center of the window between the window and the installation base. and an inner member, the inner member controlling a flow rate of the carrier gas within the cell body by restricting a size of a filling space for the carrier gas within the cell body. Effect of the Invention

[0013] According to the present invention, it is possible to provide a technique for suppressing convection within a cell and improving the flow rate of a carrier gas. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing the configuration of a cell for laser ablation according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram for explaining a method for placing an object to be measured in the cell for laser ablation. [Diagram 3]FIG. 3 is a configuration diagram showing the installation state and operating direction of the slit member in the cell for laser ablation. [Figure 4] FIG. 4 is a diagram showing the gas flow around the slit member in the cell for laser ablation. [Diagram 5] 5(a) and 5(b) are configuration diagrams showing the operating state of the slit member in the cell for laser ablation. [Figure 6] 6(a) and 6(b) are configuration diagrams showing an improved example of the slit member in the cell for laser ablation. [Figure 7] FIG. 7 is a diagram showing the configuration of a cell for laser ablation according to the second embodiment of the present invention. [Figure 8] FIG. 8 is a partial cross-sectional view of the cell for laser ablation. [Figure 9] 9(a), 9(b) and 9(c) are diagrams showing the configuration of the inner member of the cell for laser ablation. [Figure 10] FIG. 10 is a diagram showing vertical convection of gas in a cell according to the conventional technology. [Figure 11] FIG. 11 is a diagram showing convection of gas in the depth direction in a cell according to the conventional technology. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] First Embodiment The cell for laser ablation according to the first embodiment of the present invention controls the gas path inside the cell body by providing a variable or detachable slit member inside the cell.

[0017] FIG. 1 is a perspective view showing the configuration of a cell for laser ablation according to a first embodiment of the present invention, and FIG. 2 is a perspective view showing the state in which an installation block of the cell is pulled out, which will be described.

[0018] As shown in Figures 1 and 2, a laser ablation cell 1 is configured by mounting a port block 3A as an inlet part on the carrier gas inlet side of a cell body 2, a port block 3B as an outlet part on the outlet side, and further mounting a detachable mounting block 7 to the cell body 2. In this example, bolts 12 are used to mount the port blocks 3A and 3B to the cell body 2. The cell body 2 is hollow inside and has an opening on its top surface, in which a window 4 is mounted by a cover member 5. In this example, bolts 11 are used to mount the window 4 by the cover member 5.

[0019] A carrier tube 9A is connected to the port block 3A on the carrier gas inlet side via a valve 8A, and a carrier tube 9B is connected to the port block 3B on the outlet side via a valve 8B. The end of the carrier tube 9B opposite to the end connected to the port block 3B is connected to an inlet (plasma ion source) 50 of the ICP-MS (OES).

[0020] Here, laser light from a laser light source not shown is irradiated onto the sample 11 in the cell body 2 from the direction indicated by symbol D3 in the figure, carrier gas is introduced from the direction indicated by symbol D1 in the figure, and aerosol is discharged in the direction indicated by symbol D2 in the figure.

[0021] As shown in FIG. 2, the installation block 7 is attached to the cell body 2 by inserting it into the cell body 2 from the opening 2A of the cell body 2 in the depth direction (Z-axis direction). Locking members 6A and 6B operated by a handle portion 6C are provided on the installation block flat portion 7A of the installation block 7, and the locking of the locking members 3A-2 and 3B-2 provided on the port blocks 3A and 3B is opened and closed by operating the handle portion 6C. That is, the installation block 7 is inserted from the opening 2A of the cell body 2, and the locking members 6A and 6B are engaged with the locking members 3A-2 and 3B-2 by operating the handle portion 6C, and the position is fixed. The installation table 10 is attached to the recess 7C of the installation block 7, and the sample 11 to be measured is placed on the upper flat surface of the installation table 10.

[0022] 3, 4, 5(a) and 5(b) show and explain the installation state and operating direction of the slit in the cell for laser ablation.

[0023] As shown in Figure 3, the carrier gas introduced through the inlet passage 3A-1 of the port block 3A is introduced into the inside of the cell body 2, but in the laser ablation cell 1 of this embodiment, a slit 13 is interposed at the connection end between the cell body 2 and the port block 3A to control the flow of the carrier gas introduced into the inside of the cell body 2.

[0024] More specifically, in this example, the slit 13 is fixed in position on the flat surface of the connection end of the port block 3A by bolts 14A-14C, but the hole on the slit 13 side into which the bolt is inserted is a long hole with a width in the height direction (Y-axis direction), so that by adjusting the tightening position of the bolt, the opening area of ​​the outlet at the connection end of the inlet passage 3A-1 of the port block 3A can be adjusted in the height direction by the slit 13. In this way, by operating the slit 13 in the height direction, it is possible to control the up and down airflow of the carrier gas in the cell main body 2, and for example, in the state shown in Figure 4, the carrier gas becomes a downward airflow when passing through the slit from the inlet passage 3A-1 to the surface of the sample 11 to be measured.

[0025] 5(a) shows the slit 13 raised to its upper limit and fixed in position, and FIG. 5(b) shows the slit 13 lowered to its lower limit and fixed in position. In this example, the slit 13 has three vertical long holes 13A, 13B, and 13C arranged at equal intervals in the depth direction, and these are fixed in position to the plane of the connection end of the port block 3A by bolts 14A, 14B, and 14C, respectively.

[0026] In this configuration, the sample 11 to be measured is placed on the installation table 10 installed on the installation block 7, and the installation block 7 is housed in the cell body 2, and the handle 6C is operated to engage and lock the lock members 6A and 6B with the lock members 3A-2 and 3B-2. Then, the carrier gas is introduced into the cell body 2 through the introduction path 3A-1 of the port block 3A. At this time, since the slit 13 is interposed between the port block 3A and the cell body 2, the width (opening area) of the introduction port is regulated (controlled), and the carrier gas becomes a downward air current when passing through the slit and is directed to the surface of the sample 11 to be measured. Then, in this state, the laser light from the laser light source (not shown) is irradiated through the window 4 toward the sample 11 to be measured, and the aerosol (particles) are transported to the introduction port of the ICP-MS through the outlet path 3B-1 of the port block 3B, the valve 8B, and the transport tube 9B.

[0027] In the elemental analysis method by laser ablation using the cell for laser ablation 1 according to an embodiment of the present invention, it is possible to selectively analyze only the areas irradiated with the laser, and mainly quantitative analysis and two-dimensional or three-dimensional distribution analysis are possible.

[0028] Here, FIG. 6(a) and FIG. 6(b) show the configuration of an improved example of a slit in a cell for laser ablation, and the configuration will be described.

[0029] 6(a), a plurality of holes 20A are provided above the slit 20 at non-equidistant intervals in the depth direction of the cell body 2 (longitudinal direction of the slit 20), and holes 20B, 20C, and 20D are provided below the holes 20A for fixing the position with bolts. In this way, by replacing the slit 20 with one having a plurality of holes 20A at non-equidistant intervals in the depth direction of the cell body 2, it becomes possible to control the amount of gas ejected in the depth direction.

[0030] 6(b), the slit 21 is provided with an elongated hole 21A extending in the depth direction of the cell body 2 (the longitudinal direction of the slit 21), and holes 21B, 21C, and 21D are provided below the hole 21A for fixing the position with bolts. In this way, by replacing the slit 21 with a slit 21 having an elongated hole 21A in the depth direction of the cell body 2, the depth and the upper limit of the airflow can be restricted.

[0031] According to the cell for laser ablation of the first embodiment of the present invention, by interposing a slit member between the cell body and the port block on the inlet side, it is possible to control the gas path within the cell body by regulating the size of the outlet of the port block.

[0032] <Second embodiment> The laser ablation cell according to the second embodiment of the present invention controls the gas flow rate within the cell body by providing a removable inner member within the cell.

[0033] FIG. 7 is a perspective view showing the configuration of a cell for laser ablation according to a second embodiment of the present invention, and FIG. 8 is a partial cross-sectional view of the same cell, which will be described.

[0034] As shown in these figures, in the cell for laser ablation 31 according to the second embodiment, a port block 33B on the side surface of the cell body 2 can be removed, and an inner member 40 can be inserted or removed.

[0035] As shown in Fig. 7 and Fig. 8, the cell for laser ablation 31 is configured by mounting port blocks 33A, 33B on the inlet and outlet sides of the carrier gas of the cell body 32, and further mounting a removable installation block 37 on the cell body 32. The cell body 32 is hollow inside, and its upper surface is an opening, in which a window 34 is installed by a cover member 35. A carrier tube is connected to the port block 33A on the carrier gas inlet side via a valve 38A, and a carrier tube is connected to the port block 33B on the outlet side via a valve 38B. Here, the laser light from a laser light source (not shown) is irradiated to the sample through the window 34 in the height direction of the cell body 32, from above to below.

[0036] When the port block 33B is removed from the cell body 32, an opening 32A is exposed on the flat surface of the cell body 2. By inserting an inner member 40 into this opening 32A and reattaching the port block 33B to the cell body 2, the space in the cell body 2 in which the sample 11 is placed (the space filled with the carrier gas) is restricted and narrowed, making it possible to improve the gas flow rate.

[0037] The configuration of the inner member of the cell for laser ablation is shown and explained in Figures 9(a), 9(b), and 9(c), where (a) is a left side view, (b) is a plan view, and (c) is a right side view.

[0038] As shown in these figures, the inner member 40 has a hole 40A for laser irradiation in the center, and an outlet path 40B is engraved in the gas path direction centered on the hole 40A. The outlet path 40B is formed so that the inlet side of the hole 40A is wide and the outlet side is narrower than the inlet side. This makes it possible to prevent gas from filling unnecessary areas and to increase the gas flow rate at the laser irradiation area.

[0039] According to the laser ablation cell of the second embodiment of the present invention, by inserting an inner member into the cell body, the space filled with the carrier gas can be narrowed, thereby making it possible to control the gas flow rate within the cell body.

[0040] As described above, according to an embodiment of the present invention, firstly, a cell for laser ablation is provided which comprises a cell body 2, a port block 3A as an inlet part connected to the inlet side of the carrier gas of the cell body 2, a port block 3B as an outlet part connected to the outlet side of the carrier gas of the cell body 2, and a slit member 13 interposed between the connection end of the cell body 2 and the port block 3A as an inlet part, wherein the slit member 13 controls the amount of carrier gas introduced into the cell body 2 by blocking a portion of the inlet port of the port block 3A as an inlet part.

[0041] Here, the slit member 13 is attached to the port block 3A serving as the introduction part using, for example, a bolt, and the degree of shielding can be adjusted by adjusting the attachment position on the port block 3A serving as the introduction part in the vertical direction.

[0042] Alternatively, the slit member 20 may be a slit portion 20 in which a plurality of holes 20A are formed in the longitudinal direction, or a slit portion 21 in which one long hole 21A is formed.

[0043] In addition, the cell body 2 may further include an inner member 40 that is inserted into the cell body 2 in a position parallel to the bottom surface, and the inner member 40 may control the flow rate of the carrier gas inside the cell body 2 by regulating the size of the carrier gas filling space inside the cell body 2 in the height direction.

[0044] Secondly, a cell for laser ablation is provided which comprises a cell body 32, a port block 33A as an inlet part connected to the inlet side of the carrier gas of the cell body 32, a port block 33B as an outlet part connected to the outlet side of the carrier gas of the cell body 32, and an inner member 40 inserted into the inside of the cell body 2 in a positional relationship parallel to the bottom surface, wherein the inner member 40 restricts the size of the filling space for the carrier gas inside the cell body 32 in the height direction, thereby controlling the flow rate of the carrier gas inside the cell body 32.

[0045] Although the embodiment of the present invention has been described above, it goes without saying that the present invention is not limited to this embodiment and various improvements and modifications can be made without departing from the spirit and scope of the present invention.

[0046] For example, the number and shape of the holes of the slits described above are not limited to those described above, and can be designed according to the application and measurement conditions. The shape and installation position (height) of the outlet path of the inner member can also be designed according to the application and measurement conditions. Furthermore, it is possible to combine the first and second embodiments to make an ablation cell equipped with both a slit member and an inner member. [Explanation of symbols]

[0047] 1 ... laser ablation cell, 2 ... cell body, 3A, 3B ... port block, 3A-1 ... inlet path, 3A-2 ... locking member, 3B-1 ... outlet path, 3B-2 ... locking member, 4 ... window portion, 5 ... cover member, 6 ... handle portion, 6A, 6B, 6C ... locking member, 7 ... mounting block, 7A ... mounting block flat portion, 7B ... mounting block body, 7C ... recess, 8A, 8B ... valve, 9A, 9B ... conveying tube, 10 ... mounting table, 11 ... sample, 11, 12 ... screw member, 13 ... slit member, 13A, 13B, 13C ... long hole portion, 14 ... bolt, 14A, 14B, 14C ... bolt, 20 ...slit, 20A...hole, 20B, 20C, 20D...hole, 21...slit, 21A...long hole, 21B, 21C, 21D...hole, 31...cell for laser ablation, 32...cell body, 32A...opening, 33A, 33B...port block, 33A-2, 33B-2...locking member, 34...window, 35...cover member, 36...handle portion, 36A, 36B...locking member, 36C...handle portion, 37...mounting block, 37A...recess, 38A, 38B...valve, 40...inner member, 40A...hole, 40B...outlet path, 50...inlet of ICP-MS (plasma ion source).

Claims

1. A cell body; an inlet connected to the carrier gas inlet side of the cell body; an outlet portion connected to the carrier gas outlet side of the cell body; A slit member is provided between the cell body and the connection end of the introduction portion, the slit member controls the amount of the carrier gas introduced into the cell body by blocking a portion of the inlet of the introduction part, The slit member is attached to the introduction portion, and the size of the shielding is adjusted by adjusting the attachment position to the introduction portion in the height direction. Cell for laser ablation.

2. The cell body further includes an inner member that is inserted into the cell body in a positional relationship parallel to the bottom surface, and the inner member controls the flow rate of the carrier gas inside the cell body by regulating the size of a filling space for the carrier gas inside the cell body.

2. The cell for laser ablation according to claim 1.

3. A cell body having an opening at an upper portion, A window portion disposed in the opening portion; A mounting stand that is mounted on the cell body; an inlet connected to the carrier gas inlet side of the cell body; an outlet portion connected to the carrier gas outlet side of the cell body; an inner member having a hole in a center portion, the inner member being inserted into the cell body so as to face the installation base without changing the positional relationship between the window portion and the installation base and being interposed between the window portion and the installation base; Equipped with The inner member controls the flow rate of the carrier gas inside the cell body by restricting the size of the space filled with the carrier gas inside the cell body. Cell for laser ablation.

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