JP2014142307A - Electrolyte analyzer including double pipe structure sample suction nozzle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To implement an electrolyte analyzer which reduces the standby time for the start of analysis and reduces waste of an internal standard solution and performs high-reliability analysis not affected by an ambient temperature.SOLUTION: A sample suction nozzle 12 comprises: a double pipe structure comprising an inner pipe nozzle 12A for sucking a sample solution and an outer pipe 12B for circulating water at a constant temperature. A joint (IN) 12C and a joint (OUT) 12D for supplying and circulating the water at a constant temperature are connected to the outer pipe 12B. A tube 27 connected to a hot water pipe 14A is provided with air venting means 25 in order to smoothly supply and circulate the water at a constant temperature. The inner pipe nozzle 12A is warmed by heat transfer of the water at a constant temperature, which is circulated in the outer pipe 12B.

Description

  The present invention relates to an electrolyte analyzer.

  Electrolyte analyzers measure the concentration of specific electrolyte components in electrolyte solutions such as human blood and urine, and measure the concentration of ions using an ion-selective electrode. Widely used in the field.

  In the measurement method, a standard solution with a known concentration is measured in advance, and the slope is calculated using the obtained electromotive force. Further, the internal standard solution and the sample solution are measured alternately, and the potential difference and the slope are used in the sample solution. Measure the ion concentration.

  What is important in the electrolyte analyzer is the temperature stability of the measurement solution. Since the potential level at the ion selective electrode changes depending on the temperature at the time of measurement, both the sample solution and the internal standard solution at the time of measurement must be controlled within a certain temperature range in order to ensure the reliability of the data. is there.

  For this reason, as described in Patent Document 1, a part of the internal standard solution and the diluting liquid dispensing channels are passed through a temperature-controlled preheating tank, and the diluting tank and the electrolyte measurement unit also transfer heat from the preheating tank. The temperature is controlled using it. The sample suction nozzle is covered with a heat insulating cover to ensure temperature stability.

JP-A-60-73359

  In electrolyte measurement using an ion selective electrode, the electromotive force changes as shown in Equation (1) with changes in the temperature of the electrode and sample solution. Since the sample concentration is calculated from the electromotive force according to the equation (2), the measured value fluctuates if the temperature stability of the electrode or the sample solution is poor.

E = E ₀ + 2.303 × RT / zF × log (γ × C) (1)
However, in the above formula (1), E is an electromotive force, E ₀ is a constant potential determined by the measurement system, R is a gas constant, T is an absolute temperature, z is an ionic valence, F is a Faraday constant, and γ is an activity coefficient. , C is the concentration.

C (S) = C (IS) × 10 ^{(E (S) −E (IS)) / SL} (2)
In the above formula (2), C (S) is the concentration of the sample, C (IS) is the concentration of the internal standard solution, E (S) is the electromotive force of the sample, and E (IS) is the electromotive force of the internal standard solution. , SL is a slope value.

  In the electrolyte analyzer, an internal standard solution is measured before and after the sample solution in order to correct drift due to temperature change. However, since the electromotive force depends on the absolute temperature from Equation (1), the measurement starts with the temperature inside the device unstable, and the temperature rises by 0.5 ° C while measuring the internal standard solution and the sample solution. In this case, the electromotive force increases by about 0.25 mV and the concentration increases by about 1.4 mmol / L as compared with the temperature stable state. For this reason, temperature stability is important for obtaining reliable measurement results.

  Therefore, a part of the internal standard solution and dilution liquid dispensing channels are passed through the temperature-controlled preheating tank, and the temperature of the dilution tank and the electrolyte measurement unit is also controlled using the heat transfer of the preheating tank.

  However, in the electrolyte analyzer in the prior art, the temperature of the sample suction nozzle for sucking the sample solution or internal standard solution diluted from the dilution tank to the electrolyte measurement unit is controlled only by being covered with a heat insulating cover. Do not mean. Further, in order to dispense the sample solution into the dilution tank, the heat retaining cover is provided with an insertion hole for a dispensing nozzle in the upper part and is not completely sealed.

  Therefore, the temperature of the sample suction nozzle that is only covered with the heat insulating cover when the electrolyte is measured immediately after the device is turned on or due to the influence of the device installation environment, when the temperature inside the device is not stable. The temperature is lower than that of the internal standard solution and dilution liquid, dilution tank, and electrolyte measurement unit that are temperature-controlled using heat transfer in the preheat tank.

  Therefore, when the internal standard solution for drift correction passes through the sample suction nozzle, the temperature of the internal standard solution whose temperature is controlled by using the heat transfer in the preheat tank is lowered, and the next sample solution is measured. Due to the difference in temperature, accurate drift correction cannot be performed, and the analysis result may be adversely affected.

  In order to solve these problems, the electrolyte analyzer in the prior art waits until the temperature in the apparatus stabilizes, or the sample suction nozzle is heated by sucking the temperature-controlled internal standard solution several times, and the analysis result It is operated to ensure the reliability.

  However, running cost becomes a problem due to an increase in waiting time until the start of analysis and generation of useless internal standard solutions that are not used for analysis.

  The present invention has been focused on the above-mentioned problems of the prior art. The purpose of the present invention is to provide a temperature-controlled sample suction nozzle, thereby shortening the waiting time until the start of analysis and waste of the internal standard solution. It is to realize an electrolyte analyzer that performs a highly reliable analysis that is less affected by ambient temperature.

  To achieve the above object, the present invention is configured as follows.

  In an electrolyte analyzer, a dilution tank for diluting and storing a sample, a sample suction mechanism having a sample suction nozzle for sucking the diluted sample stored in the dilution tank, and an electrolyte of the sample sucked by the sample suction mechanism An electrolyte measurement unit that measures the concentration, an outer tube that surrounds the vicinity of the sample suction port of the sample suction nozzle, and a constant temperature water supply mechanism that circulates constant temperature water through the outer tube.

  ADVANTAGE OF THE INVENTION According to this invention, while shortening the waiting time until an analysis start, the waste of an internal standard solution can be reduced, and the electrolyte analyzer which performs a reliable analysis which is not influenced by ambient temperature is realizable. .

1 is a schematic configuration diagram of an automatic analyzer to which the present invention is applied. It is a flow-path schematic block diagram of the electrolyte analyzer which is one Example of this invention. It is an external view of the preheating part in one Example of this invention. It is a schematic block diagram of the double-pipe structure sample suction nozzle in one Example of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic configuration diagram of an automatic analyzer to which the present invention is applied. The electrolyte analyzer in one embodiment of the present invention is incorporated in an automatic analyzer. However, FIG. 1 omits the electrolyte analyzer, and FIG. 2 shows an electrolyte analyzer which is an embodiment of the present invention.

  1, the automatic analyzer includes a specimen (sample) container disk 260, a reaction container disk 200, a reagent container disk 30, a photometer 70, a light source 250, and a microcomputer 140.

  The reaction vessel disk 200 is provided so as to be intermittently rotatable, and a large number of reaction cells 190 made of a translucent material are arranged on the reaction disk 200 along the circumferential direction. The reaction cell 190 is maintained at a predetermined temperature (for example, 37 ° C.) by the constant temperature bath 40. The temperature of the fluid in the constant temperature bath 40 is adjusted by a constant temperature maintenance mechanism (a constant temperature water supply mechanism) 201 having a pump.

  On the sample container disk 260, a large number of sample containers 270 for storing biological samples such as blood and urine are arranged in the circumferential direction in a double manner in the illustrated example. A sample sampling mechanism 50 is disposed in the vicinity of the sample container disk 260. The sample sampling mechanism 50 mainly includes a movable arm 220 and a sampling nozzle (sample dispensing nozzle) 15 attached to the movable arm 220.

  In the sample sampling mechanism 50, the sampling nozzle 15 is appropriately moved to the dispensing position by the movable arm 220 during sample dispensing under the control of the sample dispensing control unit 100, and the sample sampling mechanism 50 moves from the sample container 270 located at the suction position of the sample container disk 260. A predetermined amount of sample is inhaled, and the sample is discharged into the reaction cell 190 at the discharge position on the reaction vessel disk 200.

  A plurality of reagent bottles 240 are placed on the reagent container disk 30 along the circumferential direction of the reagent container disk 30.

  In addition, a reagent pipetting mechanism 90 that is substantially similar to the sample sampling mechanism 50 is disposed in the vicinity of the reagent container disk 30. Under the control of the reagent dispensing control unit 120, at the time of reagent dispensing, the reagent is inhaled from the reagent bottle 240 corresponding to the inspection item positioned at the reagent receiving position on the reaction container disk 200 by the pipette nozzle provided therein, and the corresponding reaction is performed. Discharge into the cell 190.

  A stirring mechanism 80 is disposed at a position surrounded by the reaction container disk 200, the reagent container disk 30, and the reagent pipetting mechanism 90. The mixed solution of the sample and the reagent accommodated in the reaction cell 190 is stirred by the stirring mechanism 80 to promote the reaction.

  The light source 250 is arranged near the center of the reaction vessel disk 200, and the photometer 70 is arranged on the outer peripheral side of the reaction vessel disk 200. The columns of the reaction cells 190 that have been stirred are rotated so as to pass through a photometric position sandwiched between the light source 250 and the photometer 70. The light source 250 and the photometer 70 constitute a light detection system.

  The reaction liquid of the sample and the reagent in each reaction cell 190 is measured each time it crosses the front of the photometer 70 during the rotation operation of the reaction container disk 200. The scattered light analog signal measured for each sample is input to the Log conversion / A / D converter 150 via the ion interface 130 (signal lines are omitted). The used reaction cell 190 is internally cleaned by the reaction cell cleaning mechanism 60 disposed in the vicinity of the reaction vessel disk 200 to enable repeated use. The cleaning mechanism 60 is supplied with cleaning water from the cleaning water pump 110.

  In addition, the automatic analyzer includes a display unit 160, a printer 170, and a storage medium 180 connected to the interface 130.

  Next, with reference to FIG. 2, the electrolyte analyzer which is one Example of this invention is demonstrated.

  In FIG. 2, the electrolyte analyzer includes a sample container 1, an internal standard solution reagent container 2, a diluent reagent container 3, a reference electrode solution reagent container 4, and a sample solution for diluting the sample solution with the diluent. A dilution tank 5, an internal standard solution syringe 6 for dispensing the internal standard solution into the dilution tank 5, a dilution solution syringe 7 for dispensing the dilution solution into the dilution tank 5, and a comparative electrode solution as a reference electrode A sipper syringe 8 for dispensing, an internal standard solution nozzle 9 for discharging the internal standard solution to the dilution tank 5, and a dilution liquid nozzle 10 for discharging the dilution liquid to the dilution tank 5 are provided.

  Further, the electrolyte analyzer includes an electrolyte measuring unit 11 for measuring the electrolyte concentration, a sample suction nozzle 12 for sucking the sample solution or internal standard solution diluted in the electrolyte measuring unit 11 from the dilution tank 5, and the remaining A vacuum discharge nozzle 13 for discharging the solution from the dilution tank 5, a waste liquid discharge two-way solenoid valve 24 connected to the vacuum discharge nozzle 13, ion selection electrodes 11A (Na ion selection electrode), 11B (K ion selection) Electrode), 11C (Cl ion selective electrode), diluting solution, internal standard solution in a preheat tank 14 for keeping the temperature range determined in advance, and heat insulation for keeping the periphery of the electrolyte measuring unit 11 and the diluting tank 5 A cover (not shown) and a cleaning tank 16 for cleaning the sample dispensing nozzle 15 are provided.

  Next, the operation of the electrolyte analyzer according to one embodiment of the present invention will be described.

  The electrolyte measuring device sucks the sample in the sample container 1 with the sample dispensing nozzle 15 and discharges it to the dilution tank 5. Then, the diluent in the diluent reagent container 3 is supplied to the diluent pipe 14C and the diluent nozzle 10 by the operations of the diluent suction two-way solenoid valve 17, the diluent syringe 7, and the diluent discharge two-way solenoid valve 18. And the sample discharged from the sample container 1 to the dilution tank 5 is diluted.

  Next, by the operation of the pinch valve 19, the sipper syringe 8, and the two-way electromagnetic valve 20 for sucking the sipper syringe, the comparison electrode solution in the reference electrode solution reagent container 4 passes through the comparison electrode two-way electromagnetic valve 21 and the comparison electrode. Aspirate to 11D.

  Next, the sample diluted in the dilution tank 5 is moved from the sample suction nozzle 12A to the Na ion selection electrode 11A and the K ion selection electrode by the operations of the pinch valve 19, the sipper syringe 8, and the two-way electromagnetic valve 20 for sipper syringe suction. 11B and the Cl ion selection electrode 11C are attracted, and the electromotive force generated between the comparison electrode 11D and each ion selection electrode 11A, 11B, 11C is measured.

  The measured electromotive force is sent to the microcomputer 140 via the interface 130.

  On the other hand, the internal standard solution in the internal standard solution reagent container 2 is obtained by the operation of the internal standard solution suction two-way solenoid valve 22, the internal standard solution syringe 6, and the internal standard solution discharge two-way solenoid valve 23. It is discharged to the dilution tank 5 through 14B and the internal standard solution nozzle 9. The internal standard solution and the diluted sample solution are alternately transferred from the sample suction nozzle 12A to each ion selection electrode 11A, 11B, 11C, and an electromotive force generated between the comparison electrode 11D and each ion selection electrode 11A, 11B, 11C. Is measured.

  The measured electromotive force is sent to the microcomputer 140 via the interface 130.

  The microcomputer 140 calculates the sample concentration from the slope calculated by measuring a standard solution having a known concentration in advance and the difference in electromotive force between the internal standard solution and the sample solution.

  The sample and the internal standard solution in the dilution tank 5 for which the measurement has been completed are discharged out of the apparatus from the waste liquid flow path by the operation of the waste liquid discharging two-way electromagnetic valve 24 from the vacuum discharge nozzle 13.

  FIG. 3 is an external view of the preheat tank 14. In FIG. 3, the preheating tank 14 is made constant by circulating constant temperature water controlled to about 37 ° C. ± 0.1 ° C. through a hot water pipe 14A disposed therein.

  The constant temperature water circulation mechanism branches the flow path after passing through the constant temperature maintenance mechanism 201 having a pump for circulating the constant temperature water provided in the automatic analyzer and a heater for controlling the temperature of the constant temperature water, It is connected to a hot water pipe 14 </ b> A disposed inside the preheat tank 14. Thereby, constant temperature water is circulated and the preheating tank 14 is made constant temperature.

  The internal standard solution and the diluted solution pass through the internal standard solution pipe 14 </ b> B and the diluted solution pipe 14 </ b> C disposed inside the preheat tank 14, and are heated using heat transfer.

  In addition, the sample suction nozzle 12 is also temperature-controlled using the constant temperature mechanism of the preheat tank 14.

  Next, an outline of the sample suction nozzle 12 in one embodiment of the present invention will be described. FIG. 4 is a cross-sectional view for explaining the sample suction nozzle 12.

  In FIG. 4, the sample suction nozzle 12 has a double tube structure including an inner tube nozzle 12A for sucking a sample solution and an outer tube pipe 12B for circulating constant temperature water.

  Further, the outer pipe 12B has a structure in which a joint (IN) 12C for supplying and circulating constant temperature water and a joint (OUT) 12D are connected.

  Moreover, the air removal means 25 is provided in the tube 27 connected to 14 A of warm water pipes so that constant temperature water can be supplied and circulated smoothly.

  In one embodiment of the present invention, the flow path for circulating the constant temperature water in the outer pipe 12B is a hot water pipe 14A (FIG. 1) disposed inside as a constant temperature means of the preheating tank 14 (see FIG. 1). (Refer to FIG. 1). The reference pipe branches through the tube (IN) 26, the joint (IN) 12C, the outer pipe 12B, the joint (OUT) 12D, and the tube (OUT) 27, and is returned to the hot water pipe 14A (see FIG. 1). .

  That is, the inner tube nozzle 12A is heated by the heat transfer of constant temperature water circulated in the outer tube pipe 12B. In addition, in a state where the automatic analyzer is turned on and normally started up, the constant temperature water is always circulated in the outer pipe 12B, so that the inner pipe nozzle 12A is not easily radiated and kept warm. It is in.

  In the embodiment of the present invention, as shown in FIG. 4, the constant temperature water is circulated in the outer pipe 12B. However, in order to improve heat insulation, the inner pipe 12B has a double pipe structure. May be in a vacuum state.

  That is, the space region surrounded by the outer pipe 12B of the inner pipe nozzle 12A can be configured to be in a vacuum state.

  Moreover, the space | gap (space area | region) in the outer tube | pipe 12B of a double tube structure may be filled with the heat insulating material.

  Alternatively, the outer pipe 12 can be a triple pipe structure, the outermost pipe can be in a vacuum state, and the constant temperature water can be circulated through the next inner pipe.

  Thereby, accurate drift correction is possible by controlling the temperature of the aspirated measurement solution in the sample aspiration nozzle 12 to a constant temperature as in the case of the diluted solution, the internal standard solution, the dilution tank 5 and the electrolyte measuring unit 11. Thus, highly reliable analysis can be performed.

  In addition, by providing the temperature controlled sample suction nozzle 12, it becomes less susceptible to the influence of the ambient temperature, shortens the waiting time until the start of analysis, and reduces the consumption of useless internal standard solution not used for analysis. Is possible.

  The sample suction nozzle 12 may be made of metal such as stainless steel or resin.

  Furthermore, in the above-described embodiment, the example in which the electrolyte analyzer of the present invention is incorporated in the automatic analyzer and the constant temperature maintaining mechanism 201 and the microcomputer 140 are also used in the electrolyte analyzer is shown. It can also be configured as an electrolyte analyzer. In this case, the electrolyte analyzer is equipped with a constant temperature maintenance mechanism, a sample analysis, and a microcomputer for controlling the operation of the entire electrolyte analyzer.

  DESCRIPTION OF SYMBOLS 1 ... Sample container, 2 ... Reagent container for internal standard solutions, 3 ... Reagent container for dilution liquids, 4 ... Reagent container for reference electrode solutions, 5 ... Dilution tank, 6 ... Internal standard solution syringe, 7 ... Diluent syringe, 8 ... Sipper syringe, 9 ... Internal standard solution nozzle, 10 ... Diluent nozzle, 11 ... Electrolyte measuring unit, 11A ... Na Ion selection electrode, 11B ... K ion selection electrode, 11C ... Cl ion selection electrode, 11D ... Comparison electrode, 12 ... Sample suction nozzle, 12A ... Inner tube nozzle, 12B ... Outside Pipe, 12C ... Joint (IN), 12D ... Joint (OUT), 13 ... Vacuum discharge nozzle, 14 ... Preheat tank, 14A ... Hot water pipe, 14B ... Internal standard solution Pipe, 14C ... Diluent pipe, 15 ... Sample dispensing nozzle, 16 ... washing tank, 17 ... two-way solenoid valve for sucking diluent, 18 ... two-way solenoid valve for discharging diluent, 19 ... pinch valve, 20 ... shipper 2-way solenoid valve for syringe suction, 21 ... 2-way solenoid valve for reference electrode, 22 ... 2-way solenoid valve for suction of internal standard solution, 23 ... 2-way solenoid valve for discharge of internal standard solution, 24 .... Two-way solenoid valve for discharging waste liquid, 25 ... Air venting means, 26 ... Tube (IN), 27 ... Tube (OUT), 30 ... Reagent container disk, 140 ... Microcomputer 200 ... reaction vessel disk, 260 ... sample vessel disk

Claims (7)

A dilution tank for diluting and containing the sample;
A sample suction mechanism having a sample suction nozzle for sucking a diluted sample contained in the dilution tank;
An electrolyte measurement unit for measuring the electrolyte concentration of the sample sucked by the sample suction mechanism;
An outer tube surrounding the vicinity of the sample suction port of the sample suction nozzle;
A constant temperature water supply mechanism for circulating constant temperature water in the outer tube;
An electrolyte analyzer characterized by comprising: The electrolyte analyzer according to claim 1,
The constant temperature water circulation mechanism has a hot water pipe through which the constant temperature water is circulated, and the outer pipe branches from the hot water pipe. The electrolyte analyzer according to claim 2,
An internal standard solution supply pipe for supplying an internal standard solution to the dilution tank, a dilution liquid supply pipe for supplying the dilution liquid to the dilution tank, the dilution tank, the electrolyte measuring unit, the outer pipe, and the hot water pipe. An electrolyte analyzer characterized by being held and kept warm by the constant temperature water circulation mechanism. The electrolyte analyzer according to claim 3,
The electrolyte analyzer is characterized in that the sample suction nozzle and the outer tube are made of metal. A dilution tank for diluting and containing the sample;
A sample suction mechanism having a sample suction nozzle for sucking a diluted sample contained in the dilution tank;
An electrolyte measurement unit for measuring the electrolyte concentration of the sample sucked by the sample suction mechanism;
An outer tube surrounding the vicinity of the sample suction port of the sample suction nozzle;
And the space region surrounded by the outer tube of the sample suction nozzle is in a vacuum state. A dilution tank for diluting and containing the sample;
A sample suction mechanism having a sample suction nozzle for sucking a diluted sample contained in the dilution tank;
An electrolyte measurement unit for measuring the electrolyte concentration of the sample sucked by the sample suction mechanism;
An outer tube surrounding the vicinity of the sample suction port of the sample suction nozzle;
And the space region surrounded by the outer tube of the sample suction nozzle is filled with a heat insulating material. A sample container disk on which the sample container is placed; and
A reagent container disk on which the reagent container is disposed; and
A reaction vessel disk on which the reaction vessel is located; and
A sample dispensing mechanism for sucking a sample from the sample container and discharging it to the reaction container;
A reagent dispensing mechanism that aspirates the reagent from the reagent container and discharges the reagent into the reaction container;
An analysis unit for analyzing the sample stored in the reaction container;
A constant temperature maintenance mechanism for supplying constant temperature water to the reaction disk for bringing the reaction disk to a constant temperature state;
A dilution tank for diluting and storing the sample, a sample suction mechanism having a sample suction nozzle for sucking the diluted sample stored in the dilution tank, and an electrolyte for measuring the electrolyte concentration of the sample sucked by the sample suction mechanism An electrolyte analyzer having a measurement unit, an outer tube surrounding the vicinity of the sample suction port of the sample suction nozzle, and a constant temperature water supply mechanism for circulating constant temperature water from the constant temperature maintenance mechanism to the outer tube,
An automatic analyzer characterized in that it can be equipped with.

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