JP3831671B2 - Method and apparatus for injecting liquid sample into horizontal combustion tube - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid sample injection method and apparatus for a horizontal combustion furnace.
[0002]
[Prior art]
In general, in an autosampler used in a fluorescent X-ray sulfur analyzer equipped with a horizontal combustion furnace, as shown in FIG. 4, a liquid sample L is installed in a horizontal state in a horizontal combustion furnace 70 by a boat inlet method. It is fed into the combustion pipe 71. That is, the liquid sample L dripped from the needle of the syringe in the autosampler is soaked into the quartz wool 73 on the boat 72 and inserted into the combustion tube 71 together with the boat 72 to burn the liquid sample L. The liquid sample L is gasified, its components are detected by a detection unit (not shown) of the fluorescent X-ray sulfur analyzer, and the concentration of the target element (sulfur) in the liquid sample L is analyzed. In the figure, reference numeral 74 denotes a heater coil, which is installed in the horizontal combustion furnace 70 so as to surround the combustion tube 71. Reference numeral 75 denotes a measurement gas.
[0003]
[Problems to be solved by the invention]
However, in the boat inlet method, it is difficult to control the combustion rate of the liquid sample L, and the combustion becomes abrupt combustion such as deflagration, and gas that hinders measurement is likely to be generated in the measurement gas 75. Stable measurement is not possible due to interference with measurement components. The burning rate of the sample is an important parameter that affects the performance of the apparatus, and the difficulty in controlling the burning rate is a major drawback of the boat inlet system.
[0004]
An object of the present invention is to provide a method of injecting a liquid sample into a horizontal combustion tube and its mechanism capable of reliably controlling the burning rate of the liquid sample.
[0005]
[Means for Solving the Problems]
To In order to achieve the above object, an injection method of a liquid sample to the lateral combustion tube of the present invention, the upper opening of the sample container by inserting the sample suction and discharge unit intake of a liquid sample in the sample container to the sample suction and discharge portion and, before SL is rotated toward the horizontal direction after increasing the sample suction and discharge unit, the sample suction and discharge unit is inserted into the installation combustion tube toward the horizontal direction of the liquid sample in the sample suction and discharge unit It is characterized by being injected into the combustion tube.
[0006]
As a specific means for carrying out the above injection method, the liquid sample injection device for the horizontal combustion tube according to the present invention is installed in the horizontal direction, and the inlet of the liquid sample and the injected liquid sample are injected. against the combustion tube having an outlet for feeding the measured gas generated by combustion to the analyzer, and the sample suction and discharge unit for injecting the liquid sample suction, moving means for moving the sample suction and discharge unit in three-dimensional directions, the It is characterized by comprising switching means for switching the sample suction / discharge section between a suction posture and a horizontal posture which is an injection posture .
[0007]
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. The present invention is not limited thereby.
[0009]
1 to 3 show an embodiment of the present invention.
[0010]
FIG. 1 employs a syringe 2 and a needle 3 as a sample suction / discharge unit, and operates a syringe pump 6 to move a liquid sample L in the sample container 1 into the syringe 2 through the needle 3 in a vertical suction posture. After inhalation, the needle 3 rises from within the sample container 1, and after this rise, the syringe 2 and the needle 3 are switched in the horizontal direction and rotated, and the combustion tube installed in the horizontal combustion furnace 5 in the horizontal direction. 4 shows a procedure in which the needle 3 is inserted in the horizontal injection posture 4 and the liquid sample L in the syringe 2 is injected into the combustion tube 4 by operating the syringe pump 6.
[0011]
FIG. 2 shows a moving means for moving the needle 3 and the syringe 2 as the sample suction / discharge section in a three-dimensional direction (XYZ direction in the rectangular coordinates), and switching for switching the needle 3 and the syringe 2 to a vertical or horizontal posture. The syringe 2 from the initial position [I] of the syringe 2 and the needle 3 before inserting the needle 3 from the upper opening 1a of the sample container 1 to the insertion position [F] of inserting the needle 3 into the combustion tube 4 by means. The procedure up to the needle 3 is shown.
[0012]
FIG. 3 shows the cleaning liquid A used for cleaning the inner wall of the syringe 2 (the passage of the liquid sample L inside the syringe 2), the inner wall of the needle 3 (the passage of the liquid sample L inside the needle 3), and the outer periphery Q of the needle 3. A liquid sample injection device 60 including a cleaning liquid storage container 7 and a diaphragm pump 8 for sending the cleaning liquid A in the cleaning liquid storage container 7 to the syringe 2 is shown.
[0013]
The liquid sample injection device 60 automatically collects the liquid sample L and injects the collected liquid sample L into the combustion tube 4, and includes all the processes from the collection of the liquid sample L to the injection of the liquid sample L. This is an automatic sampling device called an auto sampler, in which the process is performed automatically. In the present invention, a method of inhaling the liquid sample L into the syringe 2 through the needle 3 and a method of directly injecting the liquid sample L in the syringe 2 into the combustion tube 4 through the needle 3 are adopted. The combustion rate of the liquid sample L can be reliably controlled. Moreover, the washing | cleaning process of the syringe 2 and the needle 3 after injection | pouring of the liquid sample L is also performed automatically.
[0014]
1 to 3, a liquid sample injection device 60 has an upper opening 1a and a plurality of sample containers 1 containing liquid samples L such as gasoline, and these sample containers 1 are placed thereon. The tray 65, the needle 3 inserted into the combustion tube 4, and the liquid sample L from the sample container 1 are sucked through the needle 3, while the liquid sample is inserted into the combustion tube 4 into which the needle 3 is inserted via the needle 3. It operates so that the liquid sample L is inhaled into the syringe 2 via the syringe 2 for injecting L and the needle 3, and operates so that the liquid sample L in the syringe 2 is injected into the combustion tube 4. Syringe pump 6, cleaning means for syringe 2 and needle 3, moving means for moving needle 3 and syringe 2 in a three-dimensional direction (XYZ direction in rectangular coordinates), needle 3 and syringe 2 more becomes mainly a switching means for switching the vertical or horizontal attitude. As described above, the syringe 2 and the needle 3 constitute a sample suction / discharge unit. In this embodiment, each sample container 1 is positioned in the shape of a grid in the form of a grid along the horizontal direction (direction indicated by a double arrow X) and the vertical direction (direction indicated by a double arrow Y). It is placed to do.
[0015]
Further, the combustion pipe 4 mainly has a substantially cylindrical combustion part 4a, and an inlet 20 and an outlet 21 which are smaller in diameter than the combustion part 4a and formed at both ends of the combustion part 4a. Then, the liquid sample L sucked into the syringe 2 by operating the syringe pump 6 is injected from the inlet 20 through the needle 3. Further, the measurement gas G generated in the combustion tube 4 due to the combustion of the liquid sample L injected into the combustion tube 4 is sent out from the outlet 21 to the detector of the analyzer. In addition, two gas flow paths communicate with the inlet 20. One is a mixed gas channel i in which carrier gas and oxygen are mixed, and the other is an oxygen channel j. As the carrier gas, an inert gas such as Ar that does not react with oxygen is used.
[0016]
The syringe pump 6 operates when the liquid sample L in the sample container 1 is sucked into the syringe 2 through the needle 3 and operates when the liquid sample L in the syringe 2 is injected into the combustion tube 4. To do.
[0017]
The cleaning means includes a cleaning liquid storage container 7 that stores a cleaning liquid A such as ethanol used for cleaning the inner wall of the syringe 2, the inner wall of the needle 3, and the outer periphery Q of the needle 3, and a cleaning liquid storage container 6. Diaphragm pump 8 that functions to feed the cleaning liquid A into the syringe 2, a cleaning container 13 having, for example, a circular hole waste liquid port 12, and a circular hole cleaning tank in which the needle 3 of the syringe 2 formed in the cleaning container 13 is inserted. 14.
[0018]
Reference numeral 10 denotes a three-way electromagnetic valve that switches between cleaning of the syringe 2 and the needle 3 serving as a sample suction / discharge unit and when sucking and injecting the liquid sample L. The first valve unit 10a, the second valve unit 10b, and the third valve It consists of the valve part 10c.
[0019]
At the time of cleaning, the first valve portion 10a and the second valve portion 10b are in the open state so that the two valves 10a and 10b communicate with each other, while the third valve portion 10c is in the closed state, and passes through the diaphragm pump 8 from the cleaning liquid storage container 7 and the syringe 2 and A cleaning flow path reaching the needle 3 is formed. That is, the diaphragm pump 8 is provided between the three-way electromagnetic valve 10 and the cleaning liquid storage container 7, and the diaphragm pump 8 allows the cleaning liquid A in the cleaning liquid storage container 7 to pass through the three-way electromagnetic valve 10 to the inside of the syringe 2. , And fed into the needle 3.
[0020]
Further, at the time of inhalation / injection, the second valve portion 10b and the third valve portion 10c are opened and the both 10b and 10c communicate with each other, while the first valve portion 10a is closed, and the sample container 1 to the needle 3 and the syringe 2 An inhalation / injection flow path that passes through and reaches the syringe pump 6 is formed.
[0021]
That is, inhalation is performed by pushing down the piston 6a in the syringe direction 6 in the syringe pump 6 as the suction / discharge control unit, while injection is performed by pushing up the piston 6a in the direction E. The injection speed (discharge speed) of the liquid sample L is proportional to the amount by which the piston 6a is pushed up in the E direction. The amount of pushing up / down of the piston 6a is controlled by an actuator.
[0022]
Further, the cleaning means causes the cleaning liquid A to pass through the syringe 2 and the needle 3 by the diaphragm pump 8 and discharges the cleaning liquid A from the needle tip 3 a to the cleaning liquid reservoir 14 of the cleaning tank 13. The cleaning liquid having a flow rate larger than that of the cleaning liquid flowing out of the cleaning liquid is accumulated in the cleaning liquid reservoir 14 of the cleaning tank 13 and the cleaning liquid reservoir 14 is filled with the cleaning liquid. That is, the diameter of the cleaning liquid reservoir 14 of the cleaning tank 13, the diameter of the waste liquid port 12, the cleaning liquid discharge flow rate from the needle tip 3 a, the height of the cleaning liquid reservoir 14 of the cleaning tank 13, and the cleaning liquid reservoir 14 of the needle 3 By taking into account the relationship of the insertion length of the needle and the like, the cleaning tank 13 can be filled with the cleaning liquid and the outer periphery Q of the needle 3 can also be cleaned by appropriately setting these values.
[0023]
The combustion tube 4 is horizontally long and flat in the X direction, and has a heater coil 15 disposed along the X direction. The combustion tube 4 is surrounded by the heater coil 15 in the X direction. Arranged along the direction. Since the combustion tube 4 is flat and the combustion tube 4 is surrounded by the heater coil 15, the vertical direction (Z direction), the lateral direction (X direction), and the vertical direction (Y direction) inside the combustion tube. For example, even if the liquid sample L falls on the lower part of the combustion tube 4, there is an advantage that it does not remain unburned and burns and the analysis value does not become abnormal.
[0024]
The characteristic configuration of the present invention will be described below.
[0025]
The combustion tube 4 has a heat-resistant sealing member 23 that seals the inlet 20. The sealing member 23 is made of a material that allows the needle tip 3a to be inserted into the combustion tube 4 by inserting (piercing) the needle tip 3a, for example, heat resistant rubber. Then, the needle 3 is directly inserted (pierced) toward the substantial center of the sealing member 23 which is installed in advance to seal the inlet 20, and the piston 6 a of the syringe pump 6 is moved in a state where the needle tip 3 a penetrates the sealing member 23. By pushing up in the E direction, the liquid sample L can be injected into the combustion tube 4 while controlling the injection speed (discharge speed) of the liquid sample L.
[0026]
Then, the liquid sample L is burned in the combustion tube 4. The liquid sample L is gasified and its components are detected by, for example, a detection unit of a fluorescent X-ray sulfur analyzer, and the concentration of the target element (sulfur) in the liquid sample L is analyzed.
[0027]
Hereinafter, the switching means and the moving means will be described.
[0028]
The switching means rotates the syringe mounting block 34 to which the syringe 2 is mounted, and the syringe mounting block 34 around the rotation axis H along the XZ plane by 90 °, whereby the syringe 2 When injecting the liquid sample L into the combustion tube 4, the needle 3 and syringe 2 are switched from the vertical posture (J) to the horizontal posture (K) as shown in FIG. When washing 2, the needle 3 and the motor 2 are stored in a horizontal posture (K) and a motor housing block 29 that houses a motor for switching the syringe 2 to a vertical posture (J). The moving means includes a sliding member 29a (see FIG. 3) attached to the motor housing block 29, and a direction (vertical direction) of the motor housing block 29 via the sliding member 29a. Frame portion 30 provided along the Z direction, a sliding member 30a attached to an intermediate position of the frame portion 30, and the frame portion 30 via the sliding member 30a. A frame portion 31 provided along the Y direction for sliding in the direction (vertical direction) indicated by the double arrow Y, a sliding member 31a attached to the lower surface side at one end of the frame portion 31, and the sliding portion A frame portion 32 provided mainly along the X direction for sliding the frame portion 31 in the direction (lateral direction) indicated by the double arrow X via the moving member 31a is mainly provided. There.
[0029]
Further, the moving means has a motor storage box 30b that stores a motor for sliding the motor storage block 29 in the Z direction, and a motor for sliding the frame portion 30 in the Y direction. A motor storage box 31b is provided at one end of the frame portion 31, and a motor storage box 31c that stores a motor for sliding the frame portion 31 in the X direction is provided at one end of the frame portion 32. Have.
[0030]
Next, the operation of the needle and syringe by the moving means will be described.
[0031]
In FIG. 2, the syringe 2 and the needle 3 placed at the initial position [I] before the needle 3 is inserted from the upper opening 1 a of the sample container 1 in which the liquid sample L to be measured is accommodated are placed in the tray 65. It is placed above the placed sample container 1 and separated by a distance V. At this initial position [I], the syringe 2 and the needle 3 are in a vertical posture (J) that faces straight down in the form along the Z direction.
[0032]
The syringe 2 and the needle 3 at the initial position [I] first move appropriately in the XY direction. The syringe 2 and the needle 3 are lowered along the Z direction so that the needle 3 is inserted straight into the sample container 1. This lowering operation is performed by sliding the sliding member 29a downward in the Z direction with the syringe 2 and the needle 3 facing directly downward.
[0033]
When the needle 3 is inserted into the sample container 1 by a predetermined length, the liquid sample L is sucked into the syringe 2 by the operation of the syringe pump 6.
[0034]
While maintaining the vertical posture (J) even after inhalation, the needle 2 moves up with the syringe 2 in the direction opposite to the insertion direction so that the needle tip 3a is positioned above the upper opening 1a. This raising operation is performed by sliding the sliding member 29a upward in the Z direction.
[0035]
Thereafter, the needle 3 and the syringe 2 are rotated 90 ° around the rotation axis H together with the syringe mounting block 34 so that the needle tip 3a faces the combustion tube 4 side, and the vertical posture (J) is changed to the XY plane. The horizontal posture (K) is switched. In this case, the syringe mounting block 34 is rotated 90 ° along the XZ plane by the motor housed in the motor housing block 29.
[0036]
The rotated needle 3 and syringe 2 are directed toward the combustion tube 4 in the X direction while maintaining the horizontal posture (K).
[0037]
Subsequently, after the needle 3 and the syringe 2 are appropriately moved in the X, Y, and Z directions while facing the sealing member 23 while maintaining the horizontal posture (K), the syringe 2 and the needle 3 reach the insertion position [F]. The needle 3 itself passes through the sealing member 23 and is inserted directly into the combustion tube 4. In addition, if the inlet 20 provided with the sealing member 23 is tapered, the guide 3 functions as a guide when the needle 3 is inserted into the combustion tube 4. Can be easily inserted into. Thereby, the liquid sample L can be injected into the combustion tube 4 at an injection speed (discharge speed) controlled by the actuator so as to reliably control the combustion speed of the liquid sample L. As a result, conventional rapid combustion can be prevented and stable measurement can be performed.
[0038]
After injecting the liquid sample L into the combustion tube 4, the needle tip 3a is taken out from the combustion tube 4, and the needle 3 and the syringe 2 are appropriately XY while maintaining a horizontal posture (K) along the XY plane. -After moving in the Z direction, the horizontal posture (K) is rotated by 90 ° to switch to the vertical posture (J) along the Z direction, and the needle 3 and the syringe 2 are directed toward the cleaning liquid reservoir 14 of the cleaning tank 13. Then, the needle 3 is inserted straight into the cleaning liquid reservoir 14 of the cleaning tank 13. After washing, the syringe 2 and the needle 3 are lifted, moved appropriately in the XYZ directions while maintaining the vertical posture (J), and finally return to the initial position [I].
[0039]
In this embodiment, a fluorescent X-ray sulfur analyzer that analyzes the sulfur component contained in the liquid sample L is used. However, a carbon component, a nitrogen component, or a chlorine component other than the sulfur component contained in the liquid sample L is detected. Even in this case, the measurement gas 21 can be analyzed using a corresponding analyzer.
[0040]
In the present invention, the vertical combustion furnace is not used. In the vertical combustion furnace, it is not necessary to rotate the syringe 2 and the needle 3, but the vertical combustion furnace has a high temperature at the top and a low temperature at the bottom. This is because if the liquid sample L falls in the lower part, it remains unburned and the analysis value becomes abnormal.
Note that reference numeral 61 in FIG. 2 denotes a base on which the sample container 1, the cleaning container 13, the cleaning tank 14, and further switching means and moving means are provided.
[0041]
【The invention's effect】
As described above, the present invention can provide a method and an apparatus for injecting a liquid sample into a horizontal combustion tube that can reliably control the burning rate of the liquid sample.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a main part configuration showing an embodiment of the present invention.
FIG. 2 is a configuration explanatory diagram showing a state of three-dimensional automatic movement including rotation of a needle and a syringe as a sample suction / discharge portion in the embodiment.
FIG. 3 is a configuration explanatory view showing a state of three-dimensional automatic movement including rotation of a needle and a syringe as a sample suction / discharge section in the embodiment and a cleaning operation of the needle and the syringe.
FIG. 4 is an explanatory diagram of a main part configuration showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sample container, 1a ... Upper opening, 2 ... Syringe (sample suction / discharge part), 3 ... Needle (sample suction / discharge part), 4 ... Combustion tube, L ... Liquid sample.

Claims (2)

From the upper opening of the sample container by inserting the sample suction and discharge unit sucks a liquid sample in the sample container to the sample suction and discharge portion, is rotated toward the horizontal direction after increasing the previous SL sample suction and discharge unit, the sample A method of injecting a liquid sample into a horizontal combustion tube, wherein the suction / discharge portion is inserted into a combustion tube installed in a lateral direction, and the liquid sample in the sample suction / discharge portion is injected into the combustion tube. A sample which is installed in the lateral direction and injects the sucked liquid sample into a combustion tube having an inlet through which the liquid sample is injected and an outlet through which the measurement gas generated by combustion of the injected liquid sample is sent to the analyzer. A horizontal type comprising a suction / discharge section, a moving means for moving the sample suction / discharge section in a three-dimensional direction, and a switching means for switching the sample suction / discharge section between a suction posture and a horizontal posture which is an injection posture. injection system for a liquid sample to the combustion tube.

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