CN107202731B - An ultra-fast multi-exit laser ablation cell - Google Patents

Abstract

The invention provides an ultra-fast multi-outlet laser ablation cell, which includes a sample chamber shell and a quick-insert sample cell. The upper surface and the lower surface of the sample chamber shell are respectively provided with an observation window and a transmitted light window. The sample There is a sample placement port on the left side of the chamber housing, and the quick-insert sample cell is fixed in the hollow cavity in the sample chamber housing through the sample placement port, and the quick-insert sample cell has a The sample holding chamber with a concave surface, the upper surface and neck of the quick-insert sample cell are sealed with the sample chamber casing, and a plurality of air outlets arranged side by side are opened on the right side of the sample chamber casing , the left side of the sample chamber casing is provided with a carrier gas inlet hole, and both the gas outlet hole and the carrier gas inlet hole extend inward and communicate with the sample holding chamber. The beneficial effect of the present invention is that the generation of eddy current can be effectively restrained and the memory effect can be alleviated or even eliminated.

Description

An ultra-fast multi-exit laser ablation cell

technical field

The invention relates to the technical field of laser ablation technology, in particular to an ultra-fast multi-exit laser ablation pool.

Background technique

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a new technology for solid analysis that was born in the middle and late 1980s. LA-ICP-MS technology has the advantages of in-situ, real-time and rapid analysis, high sensitivity, good spatial resolution, multi-element determination and detection ability that can provide isotope ratio information. This technology has been widely used in earth science, material science, environmental science, nuclear science and other fields. It has become the mainstream conventional mineral micro-area element and isotope analysis instrument.

In the laser ablation plasma mass spectrometry analysis, the sample to be tested needs to be placed in the laser ablation cell first, and the sample aerosol generated on the surface of the laser ablation sample is brought into the plasma mass spectrometer by the carrier gas for element and isotope analysis. The design of different laser ablation cells will have a significant impact on the elemental analysis signal strength, signal stability, element fractionation and sample preparation efficiency. The position on the side of the traditional laser ablation pool is prone to eddy currents, resulting in serious element fractionation and memory effects, which ultimately affect the transmission of aerosols and the accuracy of analysis results. The problem still exists in the traditional laser ablation cell is that it takes a long time to change the sample, and it is easy to mix air during the sample change process to cause the plasma to go out.

The traditional laser ablation cell has only one gas outlet, which corresponds to the gas inlet and runs horizontally through the side of the sample chamber. In this way, only the aerosol in the middle of the erosion pool and near the gas outlet is easily transported during the gas outlet process. Since only a single gas outlet is available, the aerosols at many corners cannot be transported well, and eddy currents are likely to occur, which ultimately affects the stability of the analysis results. In addition, due to the limited number of samples placed in the sample chamber, sample replacement is cumbersome, frequent, and work efficiency is low.

The inner diameter of the air inlet pipe of the traditional laser ablation pool is generally greater than 0.5mm. The larger the inner diameter of the air inlet pipe, the lower the gas flow rate when the carrier gas flow rate is constant. Low gas flow rates result in longer aerosols staying in the ablation cell, leading to more severe memory effects. The lower the gas flow rate at the laser ablation point, the larger the size of the solid aerosol particles produced by laser ablation. The larger the size of the solid aerosol particles, the easier it is to ionize incompletely in the plasma, resulting in elemental fractionation.

Contents of the invention

In view of this, the embodiments of the present invention provide an ultra-fast multi-exit laser ablation cell that can effectively suppress the generation of eddy currents and reduce or even eliminate the memory effect.

An embodiment of the present invention provides an ultra-fast multi-outlet laser ablation cell, including a sample chamber housing and a quick-insert sample cell, the upper surface and the lower surface of the sample chamber housing are respectively provided with an observation window and a transmitted light window , the left side of the sample chamber housing is provided with a sample placement port, and the quick-insert sample cell is fixed in the hollow cavity in the sample chamber housing through the sample placement port, and the quick-insert sample cell It has a sample holding cavity concaved from its upper surface, the upper surface and neck of the quick-insert sample cell are sealed with the sample chamber casing, and a plurality of parallel chambers are arranged on the right side of the sample chamber casing. The air outlet hole is provided, and a carrier gas inlet hole is provided on the left side of the sample chamber housing, and both the air outlet hole and the carrier gas inlet hole extend inward to communicate with the sample holding chamber.

Further, one end of a carrier gas inlet joint passes through the front side or the rear side of the sample chamber casing, and is vertically communicated with the carrier gas inlet, and the end of the carrier gas inlet near the outside is closed Plug to prevent carrier gas from escaping.

Further, the diameter of the carrier gas inlet hole is 0.2-0.3 mm.

Further, the upper surface of the quick-insert sample cell has a top sealing ring groove of the quick-insert sample cell, and a fluorine rubber O-ring is placed in it, and the upper surface of the quick-insert sample cell passes through the fluorine rubber O-ring groove. A type seal seals with the top of the sample chamber housing.

Further, the neck of the quick-insert sample cell has a quick-insert sample cell neck sealing ring groove, and a fluorine rubber O-ring is placed in it, and the neck of the quick-insert sample cell passes through the fluorine rubber An O-ring is sealed with the left end area of the sample chamber housing.

Further, the upper surface of the sample chamber housing is concavely provided with an observation window accommodating cavity, and an observation window sealing ring groove is arranged around the side of the observation window, and a fluorine rubber O-ring sealing ring is placed in it, and the observation window The surrounding side of the fluorine rubber O-ring is sealed with the side wall of the observation window accommodating cavity.

Further, a plurality of semicircular sinking grooves are provided on one side of the opening end of the viewing window accommodation chamber.

Further, it also includes an air outlet curtain joint, the air outlet curtain joint has a plurality of docking holes connected with the air outlet holes, and an exhaust valve is also provided on the right side of the sample chamber housing.

Further, there are 3 to 6 air outlets, and the inner diameter of each air outlet is 1 to 3 mm.

Further, the opening end of the sample placement port is provided with a chamfer, and also includes a round-end handle, and a round-end handle screw hole matching the round-end handle is provided on the left side of the quick-plug type sample cell.

The beneficial effects brought by the technical solution provided by the embodiments of the present invention are: an ultra-fast multi-exit laser ablation cell of the present invention, on which a plurality of air outlets arranged side by side are opened on the right side of the sample chamber shell, The aerosol in the middle and corners of the laser ablation pool can be transmitted at the same time, so that the serious element fractionation and memory effect caused by the eddy current can be effectively curbed, and the accuracy of the analysis results can be improved by increasing the transmission rate of the aerosol.

Description of drawings

Fig. 1 is a schematic diagram of an overall structure of an ultra-fast multi-outlet laser ablation pool of the present invention;

Fig. 2 is a schematic structural view of the sample chamber housing in the ultra-fast multi-exit laser ablation cell of Fig. 1;

Fig. 3 is a schematic structural view of the quick-insert sample cell in the ultra-fast multi-outlet laser ablation cell of Fig. 1;

Fig. 4 is the structural representation of the observation window in the ultrafast multi-exit laser ablation cell of Fig. 1;

Fig. 5 is a schematic structural view of the bottom plate in the ultra-fast multi-exit laser ablation cell of Fig. 1 .

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

Please refer to Fig. 1, an embodiment of the present invention provides an ultra-fast multi-outlet laser ablation cell, which mainly includes: a sample chamber shell 1, a quick-insert sample cell 2 and an observation window located in the sample chamber shell 1 3 and the bottom plate 4 that fixes the empty shell 1 of the sample chamber.

Please refer to FIG. 2 , the sample chamber casing 1 is a hollow structure, that is, there is a hollow cavity inside, and the hollow cavity is used to accommodate the quick-insert sample cell. The upper surface and the lower surface of the sample chamber housing are respectively provided with an observation window 3 and a transmitted light window 20, the situation in the hollow cavity can be observed through the observation window 3, and the laser light can pass through the transmitted light window 20 into the hollow cavity.

The left side of the sample chamber housing 1 is provided with a sample placement port 13, and the opening end of the sample placement port 13 is provided with a chamfer 12, and the quick-insert sample cell 2 is fixed on the sample placement port 13. In the hollow cavity in the sample chamber housing 1 . The right side of the sample chamber casing 1 is provided with a plurality of air outlet holes 9 arranged side by side. In this embodiment, the number of the air outlet holes 9 is 3-6, preferably 5. The inner diameter of each air outlet hole 9 is 1-3 mm, preferably 2 mm. The right side of the sample chamber housing 1 also has an air outlet curtain joint 6, and the air outlet curtain joint 6 has a plurality of docking holes docked with the air outlet holes 9, and the butt joint holes are connected to the corresponding air outlet holes 9. For one-to-one docking, the number is also preferably five. The air outlet hole 9 is used to collect the aerosol in the hollow cavity at the air outlet curtain joint 6 , so that the aerosol is finally transported away by the air outlet curtain joint 6 . The right side of the sample chamber housing also has an exhaust valve 7. When placing the quick-insert sample cell 2, loosen the exhaust valve 7 to discharge the air in the hollow cavity. After the quick-insert sample cell 2 is put in place, the exhaust valve 7 is closed to prevent the aerosol from flowing out from the exhaust valve 7 .

The left side of the sample chamber casing 1 is provided with a carrier gas inlet hole 11, and the carrier gas inlet hole 11 is arranged at a distance of 1 mm downward from the upper surface of the sample chamber casing 1, and the carrier gas inlet The inner diameter of the pores 11 is less than 0.5 mm, specifically 0.2-0.3 mm, preferably 0.3 mm. One end of a carrier gas inlet joint 5 passes through the front side or rear side of the sample chamber housing 1, and communicates vertically with the carrier gas inlet 11, and the left side of the carrier gas inlet 11 It is blocked by epoxy resin so that the carrier gas can only flow out from the right end of the carrier gas inlet hole 11 .

Both the air outlet hole 9 and the carrier gas inlet hole 11 extend inward and communicate with the hollow cavity.

Please refer to Fig. 2 and Fig. 4, the upper surface of the sample chamber housing 1 is concavely provided with an observation window accommodating cavity, the sides of the observation window 3 are provided with an observation window sealing ring groove 17, and fluorine is placed therein. A glue O-ring, the side of the observation window 3 is sealed with the side wall of the observation window accommodating cavity through the fluorine rubber O-ring. The observation window 3 is equipped with a high lens sheet 18, the thickness of the high lens sheet 18 is 0.4-1mm, and its light transmittance is above 90%, which helps to reduce the loss of laser ablation energy. The observation window 3 is roughly rectangular.

One side of the opening end of the observation window housing cavity is provided with a plurality of semicircular sinking grooves 10, preferably the number of said semicircular sinking grooves 10 is two, and the two semicircular sinking grooves 10 are mainly used for It is convenient to disassemble or replace the high lens sheet 18, so as to facilitate the maintenance and cleaning of the observation window 3.

Please refer to FIG. 3 , the quick-insert sample cell 2 has a sample holding chamber recessed from its upper surface, and the sample holding chamber is used to hold a sample. The sample holding chamber is directly below the observation window 3 , and the situation in the sample holding chamber can be observed through the observation window 3 .

The upper surface of the quick-insert sample cell 2 has a top seal ring groove 15 of the quick-insert sample cell, and the sample holding chamber is surrounded by the top seal ring groove 15 of the quick-insert sample cell, and is located at the top of the quick-insert sample cell. The inner side of the sealing ring groove 15 on the top of the sample cell. A fluorine rubber O-ring seal is placed in the top seal ring groove 15 of the quick-insert sample cell, and the upper surface of the quick-insert sample cell 2 passes through the fluorine rubber O-ring seal and the sample chamber housing 1. Top seal.

The neck of the quick-insert sample cell 2 has a quick-insert sample cell neck sealing ring groove 14, in which a fluorine rubber O-ring is placed, and the neck of the quick-insert sample cell 2 passes through the fluorine rubber The O-ring is sealed with the left end area of the sample chamber housing 1 .

The neck of the quick-plug type sample cell 2 and its upper surface adopt the design of installing a fluorine rubber O-shaped sealing ring, so that the carrier gas introduced into it will not flow to both sides and can only flow into the outlet curtain joint 6, reducing the effective volume of the denudation pool. An exhaust valve 7 is added to the right end of the ultra-fast multi-outlet laser ablation cell, and the exhaust valve 7 is loosened when the sample is changed, and the air mixed in the sample change process can be quickly discharged from the exhaust valve 7, It avoids the conventional tedious and time-consuming exhaust process and the flameout of the instrument caused by air mixing, and significantly improves the work efficiency.

Please refer to Figure 1 and Figure 3, the ultra-fast multi-outlet laser ablation cell also includes a round handle 18, and the left side of the quick-insert sample cell 2 is provided with a round handle that matches the round handle 18 16 screw holes. The round handle 18 is fixed to the quick-insert sample cell 2 through the round-end handle screw hole 16, and by pulling the round-end handle 18, the quick-insert sample cell 2 can be easily removed from the Take out the sample chamber housing 1.

Please refer to FIG. 5 , the bottom plate 4 is fixed to the corresponding screw holes at the bottom of the sample chamber housing 1 through the M3 flat-head screw holes. The bottom plate 4 is roughly rectangular and placed on the moving slide of the laser ablation system.

The beneficial effect brought by the technical solution provided by the embodiments of the present invention is: an ultra-fast multi-exit laser ablation cell of the present invention, on which the right side of the sample chamber housing 1 is provided with a plurality of air outlets arranged in parallel 9. It can transmit the aerosol in the middle and corner of the laser ablation pool at the same time, so that it can effectively curb the serious element fractionation and memory effect caused by the generated eddy current, and improve the accuracy of the analysis results by increasing the transmission rate of the aerosol sex.

In this article, the orientation words such as front, rear, upper, and lower involved are defined by the parts in the drawings and the positions between the parts in the drawings, just for the clarity and convenience of expressing the technical solution. It should be understood that the use of the location words should not limit the scope of protection claimed in this application.

In the case of no conflict, the above-mentioned embodiments and features in the embodiments herein may be combined with each other.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection of the present invention. within range.

Claims (7)

1. An ultra-fast multi-exit laser ablation cell, comprising a sample chamber housing and a quick-insert sample cell, the upper surface and the lower surface of the sample chamber housing are respectively provided with an observation window and a transmitted light window, and the sample chamber A sample placement port is opened on the left side of the housing, and the quick-insert sample cell is fixed in the hollow cavity in the sample chamber casing through the sample placement port, and it is characterized in that: the quick-insert sample cell has A sample holding chamber concaved from its upper surface, the upper surface and neck of the quick-insert sample cell are sealed with the sample chamber casing, and a plurality of side-by-side arrangements are opened on the right side of the sample chamber casing The air outlet hole, the left side of the sample chamber shell is provided with a carrier gas inlet hole, and the air outlet hole and the carrier gas inlet hole both extend inward and communicate with the sample holding chamber; the carrier gas The aperture of the air inlet hole is 0.2-0.3mm; the number of the air outlet holes is 3-6, and the inner diameter of each of the air outlet holes is 1-3mm; the laser ablation pool also includes an air outlet curtain joint, and the air outlet curtain The joint has a plurality of docking holes which are docked with the air outlet, and the right side of the sample chamber housing is also provided with an exhaust valve. 2. The ultra-fast multi-outlet laser ablation cell as claimed in claim 1, characterized in that: one end of a carrier gas inlet joint passes through the front side or the rear side of the sample chamber housing, and is connected with the carrier gas The inlet hole is connected vertically, and the end of the carrier gas inlet hole close to the outside is blocked to prevent the carrier gas from overflowing. 3. The ultra-fast multi-outlet laser ablation cell as claimed in claim 1, characterized in that: the upper surface of the quick-insert sample cell has a top sealing ring groove for the quick-insert sample cell, and a fluorine rubber O-type A sealing ring, the upper surface of the quick-insert sample cell is sealed with the top of the sample chamber housing through the fluorine rubber O-ring. 4. The ultra-fast multi-outlet laser ablation cell as claimed in claim 1, characterized in that: the neck of the quick-insert sample cell has a quick-insert sample cell neck sealing ring groove, and fluorine rubber O is placed therein. O-shaped sealing ring, the neck of the quick-insert sample cell is sealed with the left end area of the sample chamber housing through the fluorine rubber O-shaped sealing ring. 5. The ultra-fast multi-outlet laser ablation cell as claimed in claim 1, characterized in that: the upper surface of the sample chamber shell is concavely provided with an observation window accommodating cavity, and the sides of the observation window are provided with observation window seals A ring groove, in which a fluorine rubber O-ring is placed, and the sides of the observation window are sealed with the side walls of the observation window accommodating cavity by the fluorine rubber O-ring. 6. The ultra-fast multi-outlet laser ablation cell according to claim 5, wherein a plurality of semicircular sinks are arranged on one side of the opening end of the observation window accommodation chamber. 7. The ultra-fast multi-outlet laser ablation cell according to claim 1, characterized in that: the opening end of the sample placement port is provided with a chamfer, and also includes a round handle, and the left side of the quick-insert sample cell A round head handle screw hole matched with the round head handle is opened on the surface.