Atomizer for high matrix sample detection

Abstract

The atomizer comprises an atomizer body, the atomizer body is composed of an external gas transmission pipe and an internal sample transmission pipe, a gas transmission channel is formed between the interior of the gas transmission pipe and the sample transmission pipe, the initial end of the gas transmission channel is provided with a gas inlet, and the tail end of the gas transmission channel is provided with a gas outlet. A sample transmission channel is formed in the center in the sample transmission pipe, a sample inlet is formed in the initial end of the sample transmission channel, a sample outlet is formed in the tail end of the sample transmission channel, the gas outlet is communicated with the sample outlet, an atomizer tip is arranged at the tail end of the gas transmission pipe, an aerosol channel is formed in the atomizer tip, and an aerosol outlet is formed in the tail end of the atomizer tip. The aerosol channel extends from the end of the sample transfer channel to the aerosol outlet. According to the aerosol channel, generation of finer aerosol is guaranteed, sample blockage can be reduced, and the aerosol channel is suitable for high-matrix sample detection; meanwhile, the sample detection sensitivity is improved by about two times.

Description

Technical Field

[0001] The invention relates to the technical field of mass spectrometry, and in particular to an atomizer for high-matrix sample detection. Background Art

[0002] In the field of mass spectrometry, the sample injection system is an important component. As an important component of the sample injection system, the performance of the nebulizer greatly affects the detection of samples. If the velocity of the gas at the nebulizer outlet is higher than the speed of sound, this will help to produce finer aerosols, thereby improving the analytical performance of the mass spectrometer. In addition, if new solutions are continuously wetting the inner wall of the nebulizer, the nebulizer will not be prone to tip clogging. However, the concentric nebulizers currently used are often clogged due to high salt and particle content in the sample solution, making it impossible to achieve stable sample injection, which greatly affects the performance and reliability of mass spectrometry. Summary of the invention

[0003] In order to solve the above technical problems, the present invention designs a nebulizer for high-matrix sample detection.

[0004] The present invention adopts the following technical solution: A nebulizer for high-matrix sample detection comprises a nebulizer body, the nebulizer body is composed of an external gas transmission tube and an internal sample transmission tube, a gas transmission channel is formed inside the gas transmission tube and between the sample transmission tube, an air inlet is arranged at the initial end of the gas transmission channel, and an air outlet is arranged at the end, a sample transmission channel is opened in the center of the sample transmission tube, a sample inlet is arranged at the initial end of the sample transmission channel, a sample outlet is arranged at the end of the sample transmission channel, the air outlet is connected to the sample outlet, a nebulizer tip is arranged at the end of the gas transmission tube, an aerosol channel is formed inside the nebulizer tip, an aerosol outlet is arranged at the end of the nebulizer tip, the aerosol channel extends from the end of the sample transmission channel to the aerosol outlet, and in the aerosol channel, gas and sample fully react to form an aerosol.

[0005] Preferably, the aerosol channel first gradually contracts and then expands, the length of the gradually contracting section is 0.4-0.8 mm, the length of the expanding section is 3-5 mm, and the expansion angle of the expanding section is 20°-60°.

[0006] Preferably, the gap area between the inner diameter of the gas transmission channel and the outer diameter of the sample transmission tube at the point where the aerosol channel and the sample transmission channel are flush is 0.015-0.064 mm 2 .

[0007] Preferably, the sample transmission channel tapers from an initial portion to an end portion, and has a diameter of 150-500 μm.

[0008] Preferably, the gas transmission channel is divided into two parts, one of which is a vertical part, which is perpendicular to the sample transmission channel and goes straight downward, with a diameter of 1000-2500 μm, and the other is a parallel part, which is parallel to the sample transmission channel and surrounds the sample transmission tube, and gradually shrinks near the tip of the nebulizer. The parallel part of the gas transmission channel is concentric with the sample transmission channel.

[0009] Preferably, a support is provided between the gas transmission tube and the sample transmission tube.

[0010] Preferably, the supports are arranged in multiple groups axially along the sample transmission direction, the number of which is 1-4 groups, the number of supports in each group is 1-5, and the angle between adjacent supports is 72°-360°.

[0011] Preferably, the initial end of the gas transmission pipe is provided with an air intake connection portion, which is connected to the air intake channel.

[0012] Preferably, the initial end of the sample transmission tube is provided with an injection connection. The gas transmission channel connection of the vertical part of the gas transmission channel is as close as possible to the end of the injection connection. The injection connection is directly connected to the injection channel without dead volume.

[0013] Preferably, the atomizer body is integrally formed by 3D printing.

[0014] The beneficial effects of the present invention are as follows: the present invention sets an aerosol channel at the gas transmission channel outlet and the sample transmission channel outlet, and the aerosol channel first contracts and then expands to form an accelerated aerosol. This aerosol channel ensures the generation of finer aerosols and can also reduce sample clogging, which is suitable for high-matrix sample detection; at the same time, the sample detection sensitivity is increased by about two times. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the atomizer of the present invention from a front view; Figure 2 is a schematic diagram of the cross-sectional structure of the atomizer of the present invention; Figure 3 It is a structural schematic diagram of the mass spectrometer nebulizer from the right side of the present invention; Figure 4 This is a comparison diagram of the present invention and a commercial atomizer; Figure 5 This is a test result diagram of the actual samples of the present invention and commercial atomizers; In the figure: 10, gas transmission tube, 11, gas transmission channel, 12, air inlet, 13, air outlet, 14, air inlet connection, 20, sample transmission tube, 21, sample transmission channel, 22, injection port, 23, sample outlet, 24, sample transmission channel tapered section, 25, injection connection, 30, nebulizer tip, 31, aerosol channel, 32, tapered section, 33, expansion section, 40, support. DETAILED DESCRIPTION

[0016] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings: Example: Figure 1-Figure 3 As shown, a nebulizer for high-matrix sample detection includes a nebulizer body, which is composed of an external gas transmission tube 10 and an internal sample transmission tube 20. A gas transmission channel 11 is formed between the gas transmission tube and the sample transmission tube. A sample transmission channel 21 is opened in the center of the sample transmission tube. A nebulizer tip 30 is arranged at the end of the gas transmission tube. An aerosol channel 31 is formed inside the nebulizer tip. An aerosol outlet is arranged at the end of the nebulizer tip. The aerosol channel extends from the end of the sample transmission channel to the aerosol outlet. In the aerosol channel, the gas and the sample fully react to form an aerosol.

[0017] The gas transmission channel includes two parts, one is a vertical part, which is perpendicular to the sample transmission channel and straight downward, with a diameter of 1000-2500 μm, and the other is a parallel part, which is parallel to the sample transmission channel and surrounds the sample transmission tube, and tapers near the tip of the atomizer. The parallel part of the gas transmission channel is concentric with the sample transmission channel. An air inlet 12 is set at the initial end of the gas transmission channel, and the air inlet is set at the upper part of the vertical part. An air outlet 13 is set at the end of the gas transmission channel.

[0018] The initial end of the gas transmission tube is provided with an air inlet connection portion 14. The air inlet connection portion is connected to the air inlet channel. In this embodiment, the carrier gas flow rate is 0-1.2 L / min.

[0019] A sample inlet 22 is arranged at the initial end of the sample transmission channel, a sample outlet 23 is arranged at the end of the sample transmission channel, and the gas outlet is connected to the sample outlet.

[0020] The initial end of the sample transmission tube is provided with an injection connection part 25. The injection connection part is connected to the mass spectrometer injection connection tube, and the sample enters the sample transmission channel through the connection tube. The diameter of the sample transmission channel injection port is slightly larger than the sample outlet, and its diameter gradually decreases from the sample transmission channel tapered section 24, and the tapered distance matches the tapered section at the gas transmission channel outlet.

[0021] Typically, the distance of the tapered section of the sample transmission channel is generally set to 0.1-2 mm, preferably 0.5-1 mm.

[0022] The aerosol channel first gradually contracts and then expands, the length of the gradually contracting section 32 is 0.4-0.8 mm, the length of the expanding section 33 is 3-5 mm, and the expansion angle of the expanding section is 20°-60°.

[0023] In this embodiment, the sample and gas are mixed at the starting position of the aerosol channel, and the aerosol channel first contracts and then expands to form an accelerated aerosol. This aerosol channel ensures the generation of finer aerosols and can also reduce sample clogging, which is suitable for high-matrix sample detection.

[0024] A support 40 is provided between the gas transmission tube and the sample transmission tube. The supports are provided in multiple groups axially along the sample transmission direction, the number of which is 1-4 groups, the number of supports in each group is 1-5, and the angle between adjacent supports is 72°-360°.

[0025] When the present invention is used, the injection connection part is connected to the mass spectrometry injection connection tube, the sample is transmitted through the sample transmission channel, the carrier gas is connected to the mass spectrometry carrier gas connection tube through the gas injection connection part, and is transmitted through the gas transmission channel. Under the action of the carrier gas, the sample forms an aerosol through the aerosol channel and is then ejected.

[0026] In this example, the high matrix sample nebulizer according to the preferred embodiment of the present invention was used to perform experimental operations.

[0027] This example uses an Agilent 8900 ICP-MS and a dual-channel nebulizer that comes standard with the instrument. By analyzing 10 ppb standard solutions containing different elements, standard curves of lead elements at different concentrations, and the test results of actual samples, the test results of the standard nebulizer and the high-matrix sample detection nebulizer of the present invention are compared to further verify the performance of the nebulizer of the present invention.

[0028] In this embodiment, the injection connection part is connected to the Agilent 8900 injection connection tube, and the peristaltic pump provided by the ICP-MS is used to inject the sample at a flow rate of 0.1 rps. The gas inlet connection part is connected to the carrier gas connection tube to introduce the carrier gas, and the sample is injected at the optimal flow rate of 1.1 L / min carrier gas flow rate of the standard nebulizer. Before each test, the parameters of the ICP-MS are tuned to the optimal parameters, and the content of 52Cr, 55Mn, 59Co, 75As, 85Rb, 88Sr, 133Cs, 206Pb, 207Pb, and 208Pb in the standard solutions containing 10ppb of different elements, standard curves of lead elements with different concentrations, and actual samples are measured under the tuned parameters.

[0029] The results of the 10 ppb standard solution are as follows: Figure 4 As shown, the response values ​​of the standard solutions of different elements of the nebulizer in the present invention are much higher than those of the standard nebulizer. The results show that the sensitivity of the nebulizer in the present invention is better than that of the standard nebulizer.

[0030] The standard curves of lead elements with different concentrations and the determination results of lead content in actual samples are shown in Figure 2. Figure 5 As shown in the figure, for the element lead (Pb), the R 2 The value of the standard curve of the standard nebulizer is 0.9999, and the R2 of the linear fitting of the standard curve is 1. The measured values ​​of the standard nebulizer for the content of 52Cr, 55Mn, 59Co, 75As, 85Rb, 88Sr, 133Cs, 206Pb, 207Pb and 208Pb in the actual samples and the measured values ​​of the nebulizer in the present invention were subjected to a t-test, and the results showed that P=0.275, and the two were significantly correlated.

[0031] The above test results show that the nebulizer in the present invention can not only detect elements in the standard solution with high sensitivity, but also can stably detect samples from low concentration to high concentration, and this has been verified in actual sample applications, indicating that the high-matrix sample detection nebulizer proposed in the present invention has good analytical performance and stability.

[0032] The above-described embodiment is only a preferred solution of the present invention and does not limit the present invention in any form. There are other variations and modifications without exceeding the technical solution described in the claims.

Claims

1. A nebulizer for high-matrix sample detection, comprising a nebulizer body, the nebulizer body consisting of an external gas transmission tube and an internal sample transmission tube, a gas transmission channel is formed between the gas transmission tube and the sample transmission tube, an air inlet is arranged at the initial end of the gas transmission channel, and an air outlet is arranged at the end, a sample transmission channel is opened in the center of the sample transmission tube, an inlet is arranged at the initial end of the sample transmission channel, and an outlet is arranged at the end of the sample transmission channel, and the outlet is connected to the outlet, wherein the gas inlet is connected to the outlet, and the gas inlet ... A nebulizer tip is arranged at the end of the gas transmission tube, an aerosol channel is formed inside the nebulizer tip, an aerosol outlet is arranged at the end of the nebulizer tip, the aerosol channel extends from the end of the sample transmission channel to the aerosol outlet, and in the aerosol channel, the gas and the sample fully react to form an aerosol.

2. The atomizer for high matrix sample detection according to claim 1, characterized in that: The aerosol channel first gradually contracts and then expands, the length of the gradually contracting section is 0.4-0.8 mm, the length of the expanding section is 3-5 mm, and the expansion angle of the expanding section is 20°-60°.

3. The atomizer for high matrix sample detection according to claim 1, characterized in that: The gap area between the inner diameter of the gas transmission channel and the outer diameter of the sample transmission tube at the point where the aerosol channel and the sample transmission channel are flush is 0.015-0.064 mm 2 .

4. The atomizer for high matrix sample detection according to claim 1, characterized in that: The sample transmission channel tapers from the initial part to the end, and has a diameter of 150-500 μm.

5. The atomizer for high matrix sample detection according to claim 1, characterized in that: The gas transmission channel is divided into two parts, one of which is a vertical part, which is perpendicular to the sample transmission channel and goes straight downward, with a diameter of 1000-2500 μm, and the other is a parallel part, which is parallel to the sample transmission channel and surrounds the sample transmission tube, and gradually shrinks near the tip of the nebulizer. The parallel part of the gas transmission channel is concentric with the sample transmission channel.

6. The atomizer for high matrix sample detection according to claim 1, characterized in that: A support is provided between the gas transmission tube and the sample transmission tube.

7. The atomizer for high matrix sample detection according to claim 6, characterized in that: The supports are arranged in multiple groups axially along the sample transmission direction, the number of which is 1-4 groups, the number of supports in each group is 1-5, and the angle between adjacent supports is 72°-360°.

8. The atomizer for high matrix sample detection according to claim 1, characterized in that: The initial end of the gas transmission pipe is provided with a gas inlet connection portion.

9. The atomizer for high matrix sample detection according to claim 1, characterized in that: The initial end of the sample transmission tube is provided with a sample injection connection portion.

10. The atomizer for high matrix sample detection according to claim 1, characterized in that: The atomizer body is integrally formed by 3D printing.

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