Raman detection device and method for liquid samples

Abstract

The present invention relates to a Raman detection device and method for liquid samples, wherein the detection device includes a sample detection platform, a pipette, a detection device, and a control device; the sample detection platform is provided with a plurality of sample unit slots for loading liquid samples, and the plurality of sample unit slots are evenly arranged; the pipette is provided on one side of the sample detection platform, and is used to inject liquid samples into the plurality of sample unit slots; the detection device is provided on one side of the pipette, and is used to sequentially perform Raman detection on the liquid samples in the plurality of sample unit slots. The sample unit slots can effectively reduce the liquid surface tension of the liquid sample, reduce the impact on the Raman detection results, and help improve the detection accuracy. Through the diversion effect of the arc-shaped groove of the fixed partition, the liquid sample can be evenly distributed to the plurality of sample unit slots evenly arranged on the sample detection platform, thereby achieving uniformity in Raman detection of the liquid sample, reducing the instability of the results caused by the randomness of the detection, and improving the detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical detection, and in particular to a Raman detection device and method for liquid samples. Background Art

[0002] Raman spectroscopy is a type of scattering spectrum. Based on the Raman scattering effect discovered by Indian scientist C.V. Raman, Raman spectroscopy analyzes scattered light at frequencies different from the incident light to obtain information about molecular vibrations and rotations, and is applied to molecular structure research. Raman scattered light carries specific information about the molecules in a substance, so the composition and even concentration of a substance can be analyzed by examining the Raman spectrum of a sample.

[0003] The most widely used Raman detection method for liquid samples is to mix a prepared Raman substrate with the sample to be tested, then use a capillary to draw up the liquid sample and drop it directly onto a silicon wafer or glass slide, where it is then detected using a fiber optic probe. This method has a significant drawback in actual operation. During the addition of the liquid sample, due to the cohesive and absorptive properties of the liquid, the liquid sample forms droplets on the silicon wafer or glass slide. At this point, the molecules in the surface layer are sparser than those in the liquid interior, and the distance between molecules is larger than that in the liquid interior. At the same time, the droplet thickness is distributed with a high center and low surroundings. The surface tension of the liquid affects the reproducibility and uniformity of the Raman detection results of the liquid sample. In addition, the detection method using a capillary to draw up the liquid sample results in a high degree of arbitrariness and subjectivity in the sampling point during the detection process, thus affecting the detection results of the liquid sample. Summary of the Invention

[0004] In response to the problems existing in the prior art, one of the objectives of the present invention is to provide a Raman detection device for liquid samples, which can reduce the influence of the surface tension of the liquid on the Raman detection results, avoid the arbitrariness and subjectivity of the sampling points, and improve the detection accuracy.

[0005] A second object of the present invention is to provide a Raman detection method for liquid samples.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A Raman detection device for liquid samples, comprising a sample detection platform, a pipette gun, a transmission device, a detection device and a control device;

[0008] The sample detection platform is provided with a plurality of sample unit slots for loading liquid samples, and the plurality of sample unit slots are evenly arranged;

[0009] The transmission device is connected to the control device and fixed to the sample detection platform, and is used to drive the sample detection platform to move toward the detection device so that the multiple sample unit slots correspond to the detection device in sequence;

[0010] The pipette is located on one side of the sample detection platform and is used to inject liquid samples into multiple sample unit slots;

[0011] The detection device is provided on one side of the pipette gun and is used to perform Raman detection on the liquid samples on the multiple sample unit slots in sequence;

[0012] The control device is used to control the actions of the pipette and the detection device.

[0013] Furthermore, a transmission device is included, which is connected to the control device and fixed to the sample detection platform, and is used to drive the sample detection platform to move toward the detection device so that the multiple sample unit slots correspond to the detection device in sequence.

[0014] Furthermore, the detection device includes an optical fiber probe, which is used to emit laser to the liquid sample on the sample unit groove to collect Raman light and convert the optical signal of the Raman light into an electrical signal; the optical fiber probe is correspondingly provided with a light source detector, which is used to detect the laser emitted by the optical fiber probe and control the operation of the transmission device.

[0015] Furthermore, a fixed partition is provided between adjacent sample unit grooves, the top of the fixed partition is lower than the top of the sample unit groove, the fixed partition is provided with a passage, and adjacent sample unit grooves are connected through the passage of the fixed partition.

[0016] Furthermore, the height of the fixed partition is 2.3-3.3 mm.

[0017] Furthermore, the passage is an arc-shaped groove provided on the top of the fixed partition.

[0018] Furthermore, the control device controls the movement of the transmission device by jogging, and the jogging displacement distance is smaller than the spacing distance between adjacent fixed partitions.

[0019] Furthermore, the transmission device includes a transmission belt, the transmission belt is provided with a fixing groove, and the sample detection platform is fixed to the fixing groove.

[0020] A Raman detection method for a liquid sample, using a Raman detection device for a liquid sample, comprises the following steps:

[0021] Use a pipette to inject liquid samples into multiple sample unit slots evenly arranged on the sample detection table;

[0022] The detection device is used to sequentially perform Raman detection on the liquid samples on the multiple sample unit slots.

[0023] Furthermore, the method of injecting liquid samples into multiple sample unit grooves is to use a pipette to continuously inject liquid samples into the sample unit grooves. When the liquid level reaches the arc-shaped groove at the top of the fixed partition, the liquid sample flows into the adjacent sample unit groove through the arc-shaped groove until the liquid sample is evenly distributed to multiple sample unit grooves.

[0024] Furthermore, the Raman detection of the liquid samples on the multiple sample unit slots is achieved by:

[0025] The optical fiber probe emits laser light to the liquid sample on the sample unit groove to collect Raman light and converts the optical signal of the Raman light into an electrical signal;

[0026] After the light source detector detects the laser emitted by the optical fiber probe, it controls the conveyor belt to drive the sample detection platform to move in the direction of the optical fiber probe, so that the multiple sample unit slots on the sample detection platform correspond to the optical fiber probe in sequence;

[0027] The optical fiber probe performs Raman detection on the liquid samples in the multiple sample unit slots in sequence.

[0028] In general, the present invention has the following advantages:

[0029] 1. Loading the liquid sample into the sample unit slot. Compared with the existing technology of loading the liquid sample onto a silicon wafer or glass wafer, the sample unit slot can effectively reduce the surface tension of the liquid sample, reduce the impact on the Raman detection results, and help improve the detection accuracy.

[0030] 2. Compared with the existing technology of using capillary to drip liquid samples on silicon wafers or glass sheets for detection, the sampling points are relatively random and subjective. The present invention can evenly distribute the liquid sample to multiple sample unit slots evenly arranged on the sample detection table through the diversion effect of the arc-shaped groove of the fixed partition, thereby achieving uniform Raman detection of liquid samples, reducing the unstable results caused by randomness of the detection, and improving the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the three-dimensional structure of the Raman detection device for liquid samples provided by the present invention.

[0032] Figure 2 This is a schematic front view of the Raman detection device for liquid samples provided by the present invention.

[0033] Figure 3 Schematic diagram of the top view of the sample testing platform.

[0034] Figure 4 This is a partially enlarged top view of the sample testing platform.

[0035] Figure 5This is a schematic diagram of the partially enlarged three-dimensional structure of the sample testing platform.

[0036] Figure 6 Schematic diagram of the cross section of the sample testing platform.

[0037] Figure 7 Raman spectra of methanol liquid at different heights.

[0038] Figure 8 Methanol liquid at 1036cm at different heights -1 Raman signal intensity plot at characteristic peaks.

[0039] In the picture:

[0040] 100-first support arm; 101-first vertical pole; 102-pipette; 110-sample detection platform; 111-inlet; 112-pipeline; 113-fixed partition; 114-sample slot; 115-sample unit slot; 116-light source detector; 200-conveyor belt; 201-transmission roller; 202-base; 203-fixed slot; 300-second support arm; 301-second vertical pole; 302-fiber optic probe; 400-control device. DETAILED DESCRIPTION

[0041] The present invention will be described in further detail below.

[0042] like Figure 1 and Figure 2 As shown, a Raman detection device for liquid samples includes a sample detection platform 110, a pipette 102, a detection device and a control device 400;

[0043] The sample detection platform 110 is provided with a plurality of sample unit slots 115 for loading liquid samples, and the plurality of sample unit slots 115 are evenly arranged;

[0044] The pipette gun 102 is provided on one side of the sample detection platform 110 and is used to inject liquid samples into the plurality of sample unit slots 115;

[0045] The detection device is provided on one side of the pipette gun 102 and is used to perform Raman detection on the liquid samples on the multiple sample unit slots 115 in sequence;

[0046] The control device 400 is used to control the operation of the pipette gun 102 and the detection device.

[0047] Specifically, the Raman detection device for liquid samples provided in this embodiment includes a sample injection device, a transmission device, a detection device, and a control device 400.

[0048] The sample injection device is used to add the liquid sample into the sample detection platform 110. In this embodiment, the sample detection platform 110 is made of quartz glass.

[0049] like Figure 3-Figure 6 As shown, in order to achieve micro-injection and improve detection efficiency, the sample injection device includes a sample detection platform 110, a pipette 102 and a first support arm 100. The pipette 102 is vertically arranged on the first support arm 100.

[0050] A plurality of sample slots 114 are spaced apart on the detection platform 110 and arranged in a straight line. Each sample slot 114 includes a plurality of tightly connected sample unit slots 115 .

[0051] In the sample detection station 110, each sample slot 114 is provided with a corresponding injection port 111 and a light source detector 116. Specifically, the light source detector 116 is disposed at the front end of the sample slot 114 close to the detection device and closely adjacent to the sample slot 114. In this embodiment, there are eight injection ports 111.

[0052] The injection port 111 is set to a cylindrical shape with a bottom circular diameter of 1.5mm and a height of 2.0mm. The injection port 111 is set on the sample tank 114 and is located between the sample tank 114 and the first support arm 100. The bottom of the side of the cylinder of the injection port 111 is connected to a pipe 112 with an inner diameter of 1.0mm and a length of 2.0mm. Through the pipe 112, it is connected to the bottom of the first sample unit groove 115 of the sample tank 114 close to the detection device. The sample unit groove 115 is 2.0mm wide, 3.0mm deep and 1.6mm long. The fixed partition 113 is 2.5mm high, and the arc-shaped groove on the top is 0.2mm deep and 1.0mm wide.

[0053] The injection device injects the liquid sample into the injection port 111 through the pipette 102. The liquid sample flows into the first sample unit groove 115 through the pipe 112. If the liquid sample fills the first sample unit groove 115, the liquid sample continues to flow into the second sample unit groove 115 through the passage provided by the fixed partition 113. Preferably, the passage is a circular arc groove provided on the top of the fixed partition 113. The circular arc groove of the fixed partition 113 can connect adjacent sample unit grooves 115 until the continuously injected liquid sample is evenly distributed to multiple sample unit grooves 115, completing the injection.

[0054] In this embodiment, the liquid forms a valley at the sample cell groove 115. Due to the surface tension of the liquid, the liquid molecules attract each other, resulting in an inward tension on the molecules on the liquid surface. This surface tension causes the liquid to transfer its internal pressure outward while pulling the liquid surface into a straight line. The presence of the sample cell groove 115 constrains the liquid surface to local tension at the edges of the sample cell groove 115. However, the liquid within the sample cell groove 115 is constrained by the sides of the sample cell 114 and the fixed partition 113, ensuring uniform liquid height. Furthermore, in a static liquid, the pressure at each point is the same, a fundamental law of fluid statics. When the liquid is static in the sample cell groove 115 and the sample cell groove 115 is sufficiently small, no significant height differences will occur. Therefore, loading the liquid sample into the sample cell groove 115 can effectively reduce the liquid sample's surface tension, minimizing its impact on Raman detection results and improving detection accuracy.

[0055] In this embodiment, the first support arm 100 is connected to the first upright 101. A conveyor device is provided below the pipette 102 and in the direction from the first upright 101 toward the pipette 102. The conveyor device includes a conveyor belt 200, a conveyor roller 201, and a base 202 for securing the conveyor roller 201. The conveyor belt 200 is provided with three fixed grooves 203 with a length of 76.5 mm, a width of 26.5 mm, and a depth of 1.0 mm. The fixed grooves 203 extend parallel to the direction of movement of the conveyor belt 200 and are arranged at intervals of 10.0 mm.

[0056] The transmission device is connected to the control device 400. The control device 400 controls the transmission roller 201 to rotate and drive the transmission belt 200 to move. In this embodiment, the control device 400 controls the transmission belt 200 to move at a speed of 0.8 mm / s and a point displacement of 0.8 mm.

[0057] The detection device includes a fiber optic probe 302 for emitting laser light toward the sample detection platform 110, and a second support arm 300 that supports the fiber optic probe 302. In this embodiment, the second support arm 300 is connected to a second vertical rod 301 and is used to support the fiber optic probe 302. The fiber optic probe 302 is perpendicular to the sample detection platform 110 and emits laser light toward each sample unit slot 115 to collect Raman light and convert the Raman light signal into an electrical signal.

[0058] A Raman detection method for a liquid sample, using the aforementioned Raman detection device for a liquid sample, comprises the following steps:

[0059] S1. Fix the sample detection platform 110 to the fixed groove 203 on the conveyor belt 200. Use the pipette 102 to inject the liquid sample into the injection port 111. The liquid sample flows into the first sample unit groove 115 through the bottom pipe 112. After the liquid level reaches the height of the arc-shaped groove of the fixed partition 113, the liquid sample flows into the adjacent sample unit groove 115 through the arc-shaped groove until the liquid sample is completely injected.

[0060] S2. The control device 400 is used to adjust the conveyor belt 200 to move toward the detection device. After the optical fiber probe 302 in the detection device emits laser light and is recognized by the light source detector 116, the control device 400 is adjusted to jog control the movement of the conveyor belt 200. Through jog adjustment, Raman detection is performed on each sample unit slot 115 containing a liquid sample. The optical fiber probe 302 converts the optical signal into an electrical signal. After completing the collection, it moves to the next adjacent sample unit slot 115 in the jog movement mode of the control device 400, and repeats the collection operation until all sample unit slots 115 containing liquid samples are collected.

[0061] Taking methanol as an example, the detection process of the Raman detection method for a liquid sample of this embodiment is described:

[0062] The sample detection platform 110 is fixed to the fixed groove 203 on the conveyor belt 200. The pipette 102 draws 40 μL of methanol and injects it into the injection port 111. The methanol flows into the first sample unit groove 115 through the bottom pipe 112. After the liquid level reaches the height of the fixed partition 113, the methanol flows into the second sample unit groove 115 through the arc-shaped groove. In this embodiment, 40 μL of methanol is loaded into five sample unit grooves.

[0063] The control device 400 adjusts the conveyor belt 200 to move toward the detection device. After the optical fiber probe 302 in the detection device emits laser light and is recognized by the light source detector 116, the control device 400 is adjusted to jog control the movement of the conveyor belt 200. After one jog adjustment, Raman detection of methanol is performed in the first sample unit slot 115. The optical fiber probe 302 converts the optical signal into an electrical signal. During the detection process, the parameters of the Raman instrument are set as follows: 633 laser source, laser intensity 12mW, integration time 10s, integration times 2 times, slit width 100μm, and detection spectrum range 400-1800cm -1 , resolution 1cm -1 After the collection is completed, the second sample unit slot 115 is adjusted twice to perform Raman detection on methanol, thereby completing the Raman detection of methanol in the five sample unit slots 115 .

[0064] This embodiment has the following advantages:

[0065] 1. In this embodiment, the liquid sample is loaded into the sample unit groove 115. The sample unit groove 115 can reduce the surface tension of the liquid sample, reduce the impact on the Raman detection result, and help improve the detection accuracy.

[0066] 2. Compared with the prior art that uses a capillary to drip liquid samples onto a silicon wafer or glass sheet for detection, in which the sampling points are relatively random and subjective, this embodiment uses the diversion effect of the arc-shaped groove of the fixed partition 113 to evenly distribute the liquid sample to the multiple sample unit grooves 115 uniformly arranged on the sample detection platform 110, thereby achieving uniform Raman detection of the liquid sample, reducing the unstable results caused by randomness of the detection, and improving the detection accuracy.

[0067] 3. The sample injection device, the transmission device, the detection device and the control device 400 in this embodiment can realize the integration of liquid sample injection and detection, thereby improving the detection efficiency of the liquid sample.

[0068] 4. In this embodiment, the multiple sample unit slots 115 in the sample slot 114 adopt a fence-type structure, which can achieve a minimum injection volume of 8.0 μL, and even trace samples can be accurately measured.

[0069] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A Raman detection device for liquid samples, characterized in that: It includes a sample detection platform, a pipette, a transmission device, a detection device and a control device; The sample detection table is provided with multiple sample slots at intervals, each of which includes multiple tightly connected sample unit slots; the sample unit slots are used to load liquid samples, and the multiple sample unit slots are evenly arranged; each sample slot has a corresponding injection port; the sample unit slot is 2.0mm wide, 3.0mm deep, and 1.6mm long; The transmission device is connected to the control device and fixed to the sample detection platform, and is used to drive the sample detection platform to move toward the detection device so that the multiple sample unit slots correspond to the detection device in sequence; The pipette is installed on one side of the sample detection platform, and the liquid sample is injected into the injection port through the pipette. The injection port is connected to the bottom of the first sample unit tank of the sample tank close to the detection device through a pipeline; The detection device is provided on one side of the pipette gun and is used to perform Raman detection on the liquid samples on the multiple sample unit slots in sequence; The control device is used to control the actions of the pipette gun and the detection device; A fixed partition is provided between adjacent sample unit grooves, the top of the fixed partition is lower than the top of the sample unit groove, the fixed partition is provided with a passage, and adjacent sample unit grooves are connected through the passage of the fixed partition; The passage is an arc-shaped groove provided on the top of the fixed partition; The liquid sample in the sample unit groove is constrained by the side of the sample unit groove and the fixed partition to ensure the uniformity of the liquid height and reduce the liquid surface tension of the liquid sample.

2. The Raman detection device for liquid samples according to claim 1, characterized in that: The detection device includes an optical fiber probe, which is used to emit laser to the liquid sample on the sample unit groove to collect Raman light and convert the optical signal of the Raman light into an electrical signal; the optical fiber probe is correspondingly provided with a light source detector, which is used to detect the laser emitted by the optical fiber probe and control the operation of the transmission device.

3. The Raman detection device for liquid samples according to claim 1, characterized in that: The fixed spacer height is 2.5mm.

4. The Raman detection device for liquid samples according to claim 1, characterized in that: The control device controls the transmission device to move by jogging, and the jogging displacement distance is smaller than the spacing distance between adjacent fixed partitions.

5. The Raman detection device for liquid samples according to claim 1, characterized in that: The transmission device comprises a transmission belt, a fixing groove is provided on the transmission belt, and the sample detection platform is fixed to the fixing groove.

6. A Raman detection method for liquid samples, characterized in that: A Raman detection device for a liquid sample according to any one of claims 1 to 5 comprises the following steps: Use a pipette to inject liquid samples into multiple sample unit slots evenly arranged on the sample detection table; The detection device is used to sequentially perform Raman detection on the liquid samples on the multiple sample unit slots.

7. The Raman detection method for liquid samples according to claim 6, characterized in that: The method of injecting liquid samples into multiple sample unit grooves is to use a pipette to continuously inject liquid samples at the injection port. When the liquid level reaches the arc-shaped groove at the top of the fixed partition, the liquid sample flows into the adjacent sample unit groove through the arc-shaped groove until the liquid sample is evenly distributed to multiple sample unit grooves.

8. The Raman detection method for liquid samples according to claim 6, characterized in that: The Raman detection method for liquid samples on multiple sample unit slots is as follows: The optical fiber probe emits laser light to the liquid sample on the sample unit groove to collect Raman light and converts the optical signal of the Raman light into an electrical signal; After the light source detector detects the laser emitted by the optical fiber probe, it controls the conveyor belt to drive the sample detection platform to move in the direction of the optical fiber probe, so that the multiple sample unit slots on the sample detection platform correspond to the optical fiber probe in sequence; The optical fiber probe performs Raman detection on the liquid samples in the multiple sample unit slots in sequence.

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