JP2010249612A - Pure water analyzer and method for cleaning water collecting channel of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cleaning method which automatically determines a contamination state of a water collecting channel on the basis of a condition of the last measurement, and changes the number and the content of channel cleaning operations, in order to able to reduce the consumption of cleaning water and to totally shorten its measurement period. <P>SOLUTION: The cleaning method for the collecting channel containing a plurality of channels p<SB>5</SB>-p<SB>9</SB>passing through a channel switching means 9 and a sampling syringe 11 for sampling sample water, in a pure water analyzer which conducts a TOC measurement and a conductivity measurement while switching them by using the channel switching means 9, includes: the step (a) of reading a content of the measurement conducted previously by the pure water analyzer from a data memory means of a controller 100 employed in the pure water analyzer and automatically determining whether the previously conducted measurement is the TOC measurement or the conductivity measurement, by using a previous measurement determining means of the controller 100; and the step (b) of automatically changing the number and the content of the cleaning operations for the collecting channel in accordance with the determination result, by using a change control means and a cleaning number determining means of the controller 100. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention mainly relates to a pure water analyzer for evaluating the amount of impurities contained in high-purity sample water called pure water or ultrapure water, and a method for cleaning the sampling channel, and in particular, the TOC measurement and conductivity of one unit. The present invention relates to a cleaning method for cleaning a sampling water sampling channel of a pure water analyzer (TOC / conductivity measuring device) capable of performing measurement.

In a pure water analyzer that switches the flow path with flow path switching means such as an 8-port valve and performs TOC measurement and conductivity measurement with a single unit, if a gas aeration mechanism is connected to a sampling syringe that collects sample water, Aeration treatment for discharging inorganic carbon (IC) in water as CO ₂ from the sample water and sampling of the sample water can be performed with the same sampling syringe (see Patent Document 1).

In the pure water analyzer, the conductivity can be measured by injecting sample water from a sampling syringe into a flow type conductivity cell having a pair of platinum electrodes. On the other hand, the TOC is generated by sucking sample water and hydrochloric acid into the same sampling syringe and carrying out aeration treatment, discharging the sample water as CO ₂ from the sample water, and then guiding the sample water to the TC combustion tube. by measuring the CO _2, it can be calculated directly TOC amount.

  Since the conductivity of pure water increases greatly due to the slight amount of electrolyte, when the aeration treatment is performed in the water sampling flow path as in the case of the pure water analyzer, the residual acid (= electrolyte) used in the aeration treatment remains. Greatly affects the next conductivity measurement. In order to avoid this, it is necessary to clean the sampling channel using a sufficient number of cleanings and a sufficient amount of cleaning water.

  Therefore, in the conventional pure water analyzer, in measuring the conductivity of pure water, a measurement error occurs if the water sampling flow path including the flow path through the sampling syringe and the flow path switching means is not sufficiently cleaned. The water sampling channel is washed by flowing cleaning water (pure water) through the water sampling channel.

JP 2007-93209 A

  However, in the prior art, since the washing operation of the sampling channel is always performed regardless of the measurement conditions, as a result, the measurement time of the pure water analyzer as a whole becomes long, and the cleaning water used for cleaning the sampling channel is as a result. Consumption was also great.

  In view of the above-mentioned problems, the present invention is a pure water analyzer capable of performing TOC measurement and conductivity measurement with a single unit. Automatic determination of channel contamination status, switching the content and frequency of channel cleaning, thereby reducing the overall measurement time and reducing the consumption of cleaning water and cleaning the sampling channel It aims to provide a method.

  In order to achieve the above object, the first aspect of the present invention provides a plurality of pure water analyzers that switch between TOC measurement and conductivity measurement using the flow path switching means and that pass through the flow path switching means. This invention relates to a method for cleaning a water collection flow path including a flow path and a sampling syringe for collecting sample water. That is, the water sampling flow path cleaning method according to the first aspect of the present invention includes: (a) the previous measurement determination unit included in the control device included in the pure water analyzer has the measurement performed previously from the data storage unit of the control device; A step of automatically reading whether the measurement performed by the pure water analyzer is a TOC measurement or a conductivity measurement, and (b) a switching control means and a cleaning device included in the control device according to the determination result It is summarized that the frequency determination means includes a step of automatically changing the content and frequency of cleaning of the water sampling channel.

The second aspect of the present invention switches the TOC measurement unit that measures the TOC of the sample water, the conductivity measurement unit that measures the conductivity of the sample water, and the flow path leading to the TOC measurement unit and the conductivity measurement unit. A flow path switching means, a sampling syringe that collects the sample water before introducing the sample water into the TOC measurement unit, and performs an aeration process for discharging inorganic carbon in the sample water as CO ₂ from the sample water; The present invention relates to a pure water analyzer including a measurement unit, a conductivity measurement unit, a flow path switching unit, and a control device that controls the operation of a sampling syringe. That is, the control device of the pure water analyzer according to the second aspect of the present invention includes: (a) data storage means for recording the content of the measurement previously performed by the pure water analyzer; and (b) data storage means from the previous time. The previous measurement determination means for reading the content of the measurement and determining whether the previous measurement is a TOC measurement or a conductivity measurement, and (c) a plurality of flow paths via the flow path switching means according to the determination result And a switching control means for changing the washing content of the water sampling channel including the sampling syringe, and (d) a cleaning frequency determination unit for changing the frequency of cleaning of the water sampling channel according to the determination result.

  According to the present invention, in a pure water analyzer capable of performing TOC measurement and conductivity measurement with one unit, before analyzing the sample water every time, from the state of the previous measurement, the contamination state of the water sampling channel Is provided, and a pure water analyzer and a method for cleaning the water sampling flow path are provided that can reduce the measurement time and the consumption of cleaning water by switching the content and frequency of flow path cleaning. be able to.

1 is an external view showing a pure water analyzer (TOC / conductivity measuring device) according to an embodiment of the present invention together with an autosampler 1. FIG. It is a schematic diagram which shows the pure water analyzer which concerns on embodiment of this invention. It is a schematic diagram which shows the control apparatus which comprises the pure water analyzer which concerns on embodiment of this invention. It is a schematic flowchart explaining the whole washing | cleaning method of the water sampling flow path which concerns on embodiment of this invention. It is a flowchart which shows the detail of the procedure of step S31 among the washing | cleaning methods of the water sampling flow path which concerns on embodiment of this invention. It is a flowchart which shows the detail of the procedure of step S32 among the washing | cleaning methods of the water sampling flow path which concerns on embodiment of this invention. It is a flowchart which shows the detail of the procedure of step S41 among the washing methods of the water sampling flow path which concerns on embodiment of this invention.

  Next, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic, and the same reference numerals are given to the same parts. The following embodiments of the present invention exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is the material, shape, and structure of component parts. However, the arrangement and the like are not limited to the following. The technical idea of the present invention can be variously modified within the technical scope described in the claims.

(Pure water analyzer)
As shown in FIG. 1, an overview of a pure water analyzer (TOC / conductivity measuring device) according to an embodiment of the present invention includes a pure water analyzer 2 having a conductivity measuring function added to a TOC meter, and an autosampler. 1, a sampling needle 1 a for connecting the pure water analyzer 2 and the autosampler 1 is provided, and TOC measurement and conductivity measurement are performed by one unit.

As shown in FIG. 2, the details of the pure water analyzer 2 are the flow path switching means (multiport valve) 9 having first to eighth ports and one port (seventh port) of the flow path switching means 9. a TOC measuring unit 3 connected to the ports), carriers connecting the respective feed end to the common flow path p sampling syringe 11 connected ₉ via and TOC measurement unit 3 to the common port of the passage switching device 9 The gas supply unit 5, the conductivity measuring unit 7 connected to one port of the channel switching unit 9, the channel switching unit 9, the TOC measuring unit 3, the carrier gas supply unit 5, and the conductivity measuring unit 7, respectively. It is comprised from the connected control apparatus 100, and switches and measures TOC measurement and electrical conductivity measurement using the flow-path switching means 9. FIG. The sample water autosampler 1 (offline sample water 13 via the first flow path p ₁ is connected to the first port of the flow path switching means 9 and the second port is connected to the second port via the _second flow path p _2. The second flow path p ₂ corresponds to the sampling needle 1a of FIG. 1), and the third port is used when removing inorganic carbon components from the sample water via the _third flow path p _3. The diluted hydrochloric acid 15, the fourth port has the washing water 17 through the fourth flow path p ₄ , and the fifth port has the conductivity measurement section 7, the sixth through the _fifth flow path p ₅ . The port is connected to the IC reactor 19 via the sixth flow path p ₆ , the seventh port is connected to the sample water injection section 43 of the TOC measurement section 3 via the _seventh flow path p ₇ , and the eighth port. Are connected to the drains 21 for discharge via the eighth flow path p ₈ . The sampling syringe 11 having a capacity of 5 mL incorporates a plunger 18 driven by a plunger drive motor 80.

  The carrier gas supply unit 5 includes, in order from the upstream side, a carrier gas inlet 23, an electromagnetic valve 25, a pressure regulating valve 27 for adjusting pressure, a pressure gauge 29 for measuring the pressure, a mass flow controller 31 for adjusting the flow rate, a flow meter 33, and It is configured to be connected to the humidifier 35, and is connected to a sample water injection unit 43 provided at the upper part of the TC combustion pipe 41 a via a check valve 45 of the TOC measurement unit 3. The carrier gas supply unit 5 is branched between the pressure gauge 29 and the mass flow controller 31, and is connected to a ventilation gas inlet provided at the bottom of the barrel of the sampling syringe 11 via an electromagnetic valve 37.

The TOC measurement unit 3 includes a sample water injection unit 43 connected to the seventh port of the channel switching unit 9 via the _seventh channel p ₇ and heats the sample water to generate CO ₂ . TC combustion pipe 41a, TC combustion furnace 41 for heating TC combustion pipe 41a, cooling pipe 47 having one end connected to the lower part of TC combustion pipe 41a, and one side at the other end of cooling pipe 47 A backflow prevention trap 49 connected to the end of the backflow, a lower part connected to the other end of the backflow prevention trap 49, an IC reactor 19 filled with an IC reaction solution 19 a inside, and an inlet to the top of the IC reactor 19 A dehumidifying electronic cooler 51, a halogen scrubber 61 having one end connected to the outlet of the dehumidifying electronic cooler 51, a membrane filter 63 connected to the other end of the halogen scrubber 61, and a membrane filter 63 Entrance at the other end of Connect a nondispersive infrared analysis method optics tandem cell 65 (NDIR) provided to face the light source 67 and detector 69 at both ends, connected to the outlet of the optical system tandem cell 65 CO ₂ absorber 71. Here, the upper portion of the IC reactor 19, to the sixth port of the passage switching device 9 are connected via a flow path p ₆ of the sixth, when measured separately IC is flow Sample water is directly injected into the IC reactor 19 from the sixth port of the path switching means 9. A pump 55 is connected to one place on the side wall of the IC reactor 19, and the IC reaction solution 19 a is supplied from the IC reaction solution reservoir 53. The TC combustion pipe 41 a is provided at the lower part of the sample water injection part 43, but a check valve 45 is provided at the carrier gas inlet to the sample water injection part 43. The outlet at the bottom of the TC combustion pipe 41 a is connected to a carrier gas inlet provided at the bottom of the IC reactor 19 through a cooling pipe 47 and a backflow prevention trap 49. The IC reactor 19 is provided with a drain electromagnetic valve 57, and a drain pot 59 is provided at the bottom of the dehumidifying electronic cooler 51.

The conductivity measuring unit 7 includes a conductivity measuring cell 72 composed of a quartz cylindrical chamber having an inner diameter of 2 mmφ for injecting sample water, and a flow including a pair of platinum electrodes 73 a and 73 b provided inside the conductivity measuring cell 72. Type cell. A voltmeter 74 for measuring a voltage when an alternating current is passed between the platinum electrodes 73a and 73b is connected to the platinum electrodes 73a and 73b. The conductivity measurement is performed by injecting the sample collected in the sampling syringe 11 into the conductivity measuring cell 72 via the _fifth flow path p ₅ .

In the TOC measurement, first, 100 μL of 1N dilute hydrochloric acid is added to the 2 mL of sample water collected in the sampling syringe 11 through the flow path switching unit 9, and the plunger drive motor 80 is further driven to be built in the sampling syringe 11. The plunger 18 is lowered to the aeration position, and the aeration gas is introduced into the sampling syringe 11 from the carrier gas supply unit 5 through the electromagnetic valve 37 at 100 mL / min, thereby aeration of the sample water for 90 seconds. Thus, 1000 μL of the sample water from which the IC has been removed is injected into the TC combustion pipe 41 a via the flow path switching means 9 to convert the TOC in the sample water into CO ₂ , and this is converted from the carrier gas supply unit 5 to the check valve 45. Is introduced into the optical system tandem cell 65 by the carrier gas introduced via, and its concentration is measured. The TOC concentration can be obtained by obtaining the relationship between the TOC concentration and the carbon dioxide gas concentration in advance by measuring a standard sample with a known concentration.

As shown in FIG. 3, the control device 100 shown in FIG. 2 controls the operations of the sampling syringe 11, the flow path switching unit 9, the carrier gas supply unit 5, the TOC measurement unit 3, and the conductivity measurement unit 7. And an arithmetic unit 110 for performing an operation for processing the measurement data of conductivity, and a type of measurement connected to the arithmetic unit 110, whether the previous measurement was a TOC measurement or a conductivity measurement, Data storage means 101 for storing the measurement end time, the signal of the voltage measured by the voltmeter 74 of the conductivity measuring unit 7, the data indicating the CO ₂ concentration measured by the detector 69 of the TOC measuring unit 3, and the like , A syringe operation program for operating the sampling syringe 11, a switching operation program for switching the port position of the flow path switching means 9, and a gas supply for operating the carrier gas supply unit 5 Stored programs for feeding water, washing the water sampling channel before measurement, program for operating the conductivity measuring unit 7, program for operating the TOC measuring unit 3, program for calculating conductivity, program for calculating the TOC value, etc. The program storage means 102, the input device 200, and the output device 300 are provided.

  The arithmetic device 110 drives the multi-valve drive motor 90 via the data input means 111 for inputting the measurement data and the multi-valve drive motor drive circuit 133, and selects one of the ports of the flow path switching means 9. Means 115, sampling syringe control means 116 for controlling the operation of the plunger 18 of the sampling syringe 11 by driving the plunger drive motor 80 via the plunger drive circuit 131, and carrier gas supply via the carrier gas supply device drive circuit 136 A carrier gas supply control means 117 for driving the unit 5, a conductivity measurement control means 118 for controlling the conductivity measurement operation of the conductivity measurement unit 7 via the conductivity measurement device drive circuit 132, and a data input means 111. Conductivity calculation method to calculate conductivity based on conductivity measurement data input Comprising a 119, the TOC measurement controller 120 for controlling the TOC measurement operation of the TOC measurement unit 3 via the TOC measurement device drive circuit 135, the TOC value calculating means 121 for calculating the TOC value. The arithmetic device 110 accumulates the executed control operation data in the data storage means 101, and records the accumulated TOC measurement operation and conductivity measurement operation to select the washing condition of the water sampling channel to be performed before the next measurement. As a basis for judgment.

  The interface (I / F) 130 is a device that mediates the control device 100, the flow path switching unit 9, the carrier gas supply unit 5, the conductivity measurement unit 7, and the TOC measurement unit 3. Therefore, the interface (I / F) 130 includes the plunger drive circuit 131 that generates a signal for driving the plunger drive motor 80 that operates the plunger 18 of the sampling syringe 11 and the sampling syringe 11, and the flow path switching unit 9. The operation of the multi-valve drive motor drive circuit 133 that generates a signal for connection to any of the first to eighth ports, the solenoid valve 25, the pressure regulating valve 27, and the mass flow controller 31, and the sampling syringe 11 or A carrier gas supply device drive circuit 136 that generates a signal for sending a carrier gas into the TC combustion pipe 41a, and an electromagnetic valve drive that controls the operation of the electromagnetic valve 37 and generates a signal for sending the carrier gas into the sampling syringe 11. TC combustion in the circuit 134 and the TOC measurement unit 3 41, a signal for controlling the pump 55 and drain solenoid valve 57 of the IC reactor 19, and the operation of the cooling pipe 47, the dehumidifying electronic cooler 51, the halogen scrubber 61, and the membrane filter 63 are controlled. A TOC measurement device drive circuit 135 for generating a signal for controlling the operation of the light source 67, the optical system tandem cell 65, and the detector 69, and a signal for outputting measurement data by the detector 69; The rate measuring unit 7 outputs a signal for applying an alternating current between the platinum electrodes 73a and 73b, a signal for measuring the voltage between the platinum electrodes 73a and 73b with the voltmeter 74, and a voltage measured with the voltmeter 74. A conductivity measuring device driving circuit 132 for generating a signal for performing the operation is connected.

  The measurement data output from the conductivity measuring unit 7 and the TOC measuring unit 3 is stored in the data storage unit 101, and the conductivity and the TOC value are calculated by the conductivity calculating unit 119 and the TOC value calculating unit 121, respectively. The computing device 110 is connected to an input device 200 such as a keyboard and a mouse, and an output device 300 such as a printer and a display. The hardware configuration of the pure water analyzer shown in FIG. This is a hardware configuration of a Neumann computer that includes the storage unit 102, the arithmetic device 110, the input device 200, and the output device 300. As the data storage means 101 and the program storage means 102, a volatile DRAM of a main storage device of a Neumann computer, a magnetic disk such as a hard disk (HD) of an auxiliary storage device, a magnetic tape, an optical disk, a magneto-optical disk, a RAM disk USB flash memory can be used. In FIG. 3, data input means 111, switching control means 115, sampling syringe control means 116, carrier gas supply control means 117, conductivity measurement control means 118, conductivity calculation means 119, TOC measurement control means 120, TOC value Although the arithmetic means 121 is shown to be realized in the same arithmetic device 110, it is an example as a logical configuration, and is realized as a part of a hardware configuration by another arithmetic device (CPU) or a computer system. You can also.

(TOC measurement)
Before explaining the cleaning method of the water sampling channel according to the embodiment of the present invention, referring to FIG. 2, in the analyzer for measuring by switching the TOC measurement and the conductivity measurement using the channel switching means 9 The process of directly measuring the TOC with the TOC measuring unit 3 after injecting diluted hydrochloric acid 15 into the sampling syringe 11 having a capacity of 5 mL, performing aeration treatment, removing the IC, will be described.

   (A) First, the switching control means 115 of the control device 100 drives the multi-valve drive motor 90 to align the flow path switching means 9 with the position of the second port of the autosampler 1, and the sampling syringe control means 119 The plunger drive motor 80 is driven, and 2 mL of sample water is collected from the autosampler 1 through the sampling needle 1a into the sampling syringe 11 by the suction force of the sampling syringe 11.

(B) Next, the switching control means 115 switches the flow path switching means 9 to the position of the third port for supplying the diluted hydrochloric acid 15 to the sampling syringe 11, and 100 μL corresponding to 1 standard with respect to 2 mL of sample water. Dilute hydrochloric acid 15 is sucked into the sampling syringe 11. Next, the sampling syringe control means 116 lowers the plunger 18 of the sampling syringe 11 to the ventilation position at the bottom of the barrel, the switching control means 115 connects the flow path switching means 9 to the eighth port for the discharge drain 21, The electromagnetic valve 37 is opened, high-purity air is introduced as a ventilation gas into the sampling syringe 11 at a flow rate of 100 mL / min, and the sample water in the sampling syringe 11 is aerated for 90 seconds. At this time, IC dissolved in the sample water is discharged from the sample water with the vent gas as CO _2.

(C) Next, the switching control means 115 switches the flow path switching means 9 to the position of the seventh port where the sampling syringe 11 is connected to the TC combustion pipe 41a, and the sampling syringe control means 116 changes the plunger 18 of the sampling syringe 11. Then, 1000 μL of sample water is sent to the sample water injection unit 43, and at the same time, the carrier gas supply control means 117 uses the high purity air as the carrier gas from the carrier gas supply unit 5 via the check valve 45 and the sample water injection unit 43. Send to. The carrier gas is always supplied to the TOC measuring unit 3 at a constant flow rate (for example, 150 mL / min) while the apparatus is in operation. As a result, a baseline of NDIR output is obtained, and when the sample is injected, a signal due to CO ₂ generated from the sample is observed in a peak shape. A mixture of sample water and air is introduced into the TC combustion tube 41a. Here, the TOC measurement control means 120 preheats the TC combustion tube 41a to 680 ° C. by the TC combustion furnace 41, oxidizes the carbon component of the sample water introduced into the TC combustion tube 41a, and causes the TC combustion catalyst 41b. It converted to CO _2.

(D) Next, the carrier gas supply control means 117 discharges the sample water introduced into the TC combustion pipe 41a from the lower part of the TC combustion pipe 41a. The gas (CO ₂ and water vapor) generated in the TC combustion pipe 41a is cooled by the cooling pipe 47, passes through the IC reactor 19 via the backflow prevention trap 49, and water is further removed by the dehumidifying electronic cooler 51. The halogen component is removed by the halogen scrubber 61, filtered by the membrane filter 63, and introduced into the optical system tandem cell 65.

(E) The TOC measurement control means 120 irradiates the optical system tandem cell 65 with infrared light from the light source 67, and is proportional to the CO ₂ concentration in the gas introduced into the optical system tandem cell 65. The obtained signal is obtained from the detector 69, and the TC of the sample water is obtained.

(Washing channel cleaning method)
As described above, in the pure water analyzer capable of performing the TOC measurement and the conductivity measurement with one unit using the flow path switching means 9, in the TOC measurement, dilute hydrochloric acid 15 is injected into the sampling syringe 11 for sampling. When IC is directly removed from the sample water in the syringe 11 and the TOC measurement unit 3 directly measures the TOC, the sample water from which the IC has been removed is fed into the sample water injection unit 43 and diluted hydrochloric acid is contained in the sampling syringe 11. 15 remains.

Therefore, in the water sampling channel cleaning method according to the embodiment of the present invention, prior to the TOC measurement or the conductivity measurement, the control device 100 shown in FIG. 2 and FIG. Automatically determine whether or not to wash the sampling channel based on the determination result, that is, automatically determine the procedure of cleaning the sampling channel, that is, cleaning with the cleaning water and co-washing with the sample water. It is something to execute. Here, the “water sampling flow path” includes a plurality of flow paths that pass through the flow path switching means 9 and a sampling syringe 11 that collects sample water. Specifically, the “collection flow path” means the inside of the sampling syringe 11, the common flow path p ₉ connecting the sampling syringe 11 and the common port of the flow path switching means 9, the inside of the flow path switching means 9, the flow path The fifth channel p ₅ connecting the fifth port of the switching means 9 and the conductivity measuring cell 72, the inside of the conductivity measuring cell 72, the path for discharging the sample water from the conductivity measuring cell 72, and the like.

With reference to the flowcharts of FIG. 4 to FIG. 7, a water sampling channel cleaning method according to the embodiment of the present invention will be described. The water sampling channel cleaning method described below is an example, and various other water sampling channel cleaning methods including this modification are included as long as they are within the scope of the claims. Of course, it is feasible:
(A) First, in step S1 of FIG. 4, the previous measurement determination means 112 of the control device 100 shown in FIGS. 2 and 3 reads the data stored in the data storage means 101, and the previous measurement is the conductivity measurement. It is determined whether or not there was. If it is determined in step S1 that the previous measurement was conductivity measurement, the process proceeds to step S2.

(B) In step S2, the elapsed time determination means 113 reads the data stored in the data storage means 101, calculates the elapsed time from the previous conductivity measurement end date and time, and the elapsed time has passed a predetermined threshold value. Judge whether or not there is. If it is determined in step S2 that the elapsed time is within the threshold, the process proceeds to step S31 in FIG.

 (C) As shown in FIG. 5, the details of step S31 is a step of washing the sampling channel with sample water n times in conductivity measurement (n is an integer of 2 or more, but usually n = 3 or so). The value can be adopted.) In step S311 of FIG. 5, the switching control means 115 shown in FIG. 3 drives the multi-valve drive motor drive circuit 133 in accordance with the switching operation program stored in the program storage means 102 to drive the multi-valve drive motor 90. Then, the flow path switching means 9 is adjusted to the position of the second port of the autosampler 1, and the process proceeds to step S312. In step S312, the sampling syringe control unit 116 drives the plunger drive motor 80 via the plunger drive circuit 131 in accordance with the syringe operation program stored in the program storage unit 102, and the sample of the autosampler 1 is placed in the sampling syringe 11. Water is inhaled and the process proceeds to step S313. In step S313, the sampling syringe control means 116 lowers the plunger 18 in the sampling syringe 11 to the ventilation position according to the syringe operation program, and proceeds to step S314. In step S314, the switching control means 115 drives the multi-valve drive motor 90 via the multi-valve drive motor drive circuit 133 according to the switching operation program, and the flow path switching means 9 is connected to the eighth port of the discharge drain 21. The process proceeds to step S315 according to the position. In step S315, the sample water in the sampling syringe 11 is discharged to the discharge drain 21 by moving the plunger to the upper end of the syringe with the flow path switching unit 9 directed to the eighth port. In step S316, the cleaning number determination unit 114 determines whether or not the cleaning operations in steps S311 to S315 have been performed n times. If it is not the n-th time, the process returns to step S311. If it is the nth time, step S31 is ended, and the process proceeds to the conductivity measurement in step S5 of FIG.

 (D) If it is determined in step S2 of FIG. 4 that the elapsed time exceeds the threshold, the process proceeds to step S32 of FIG. Details of step S32 are shown in FIG. Step S32 is a step of washing the sampling channel with sample water m times in the conductivity measurement (m is an integer larger than n, and can be set to m = 2n, for example). The procedure of steps S321 to S325 in step S32 is the same as the procedure of steps S311 to S315 in FIG. In step S326, the cleaning number determination means 114 determines whether or not the cleaning operations in steps S321 to S325 have been performed m times. If it is not the m-th time, the process returns to step S321. If it is the m-th time, step S32 is ended, and the process proceeds to the conductivity measurement in step S5 of FIG.

 (E) If it is determined in step S1 of FIG. 5 that the previous measurement was not conductivity measurement, the process proceeds to step S41 of FIG. 4 to wash the water sampling channel used in the TOC measurement. Details of step S41 are shown in FIG. 7. Steps S411 to S414 in FIG. 7 are substantially the same as steps S311 to S315 in FIG. 5, but the operation of lowering the plunger 18 in the sampling syringe 11 in step S313 to the ventilation position. Do not do. In step S415, it is determined whether or not the cleaning number determination means 114 has performed the cleaning operations in steps S411 to S414 a times (a is an integer equal to or greater than 2, but for example, a value of about a = 4 can be adopted. .) If it is not the a-th time, the process returns to step S411. If it has been performed a times, the cleaning with the cleaning water is terminated, and the process proceeds to step 421 in order to perform the aeration cleaning with the cleaning water.

 (F) Steps S421 to S423 are the same as steps S311 to S313 in FIG. In step S424, the carrier gas supply control means 117 drives the carrier gas supply device drive circuit 136 according to the gas supply program stored in the program storage means 102, and vents the cleaning water in the sampling syringe 11 for several seconds. The process proceeds to step S425. In step S425, the switching control means 115 drives the multi-valve drive motor 90 via the multi-valve drive motor drive circuit 133 according to the switching operation program, and the flow path switching means 9 is connected to the eighth port of the discharge drain 21. In step S426, the process proceeds to step S426. In step S426, the sample water in the sampling syringe 11 is discharged to the discharge drain 21 by moving the plunger to the upper end of the syringe with the flow path switching unit 9 directed to the eighth port. In step S427, it is determined whether or not the cleaning number determination means 114 has performed the cleaning operations in steps S421 to S426 b times (b is an integer equal to or greater than 2, but for example, a value of about b = 3 can be adopted. .) If it is not the b-th time, the process returns to step S421. If it has been performed b times, the aeration cleaning with the cleaning water is terminated, and the process proceeds to step S431 in order to perform the cleaning with the sample water.

 (G) The procedure of steps S431 to S435 is the same as the procedure of steps S311 to S315 in FIG. In step S436, it is determined whether or not the cleaning number determination means 114 has performed the cleaning operations in steps S431 to S435 c times (c is an integer equal to or greater than 2, but for example, a value of about c = 3 can be adopted. .) If it is not the c-th time, the process returns to step S431. If it has been performed c times, the process of step S41 is completed, and the process proceeds to the conductivity measurement of step S5 in FIG. 4 to measure the conductivity.

   As already explained, when the previous measurement is the TOC measurement, dilute hydrochloric acid 15 remains in the sampling syringe 11. For this reason, according to the water sampling channel cleaning method according to the embodiment of the present invention, when the TOC measurement is completed, the control device 100 automatically determines that the previous measurement was the TOC measurement (next time). Perform a careful water sampling channel cleaning process, including cleaning with cleaning water and aeration cleaning with cleaning water before the next measurement to determine whether residual dilute hydrochloric acid (regardless of whether the measurement is TOC measurement or conductivity measurement). Can be completely removed from the sampling channel. On the other hand, if the previous measurement was a conductivity measurement, the control device 100 automatically determines that the previous measurement was a conductivity measurement. In the case of the conductivity measurement, an acid or the like is added to the sampling syringe 11. Since no chemicals are used, a simple sampling channel cleaning process using only sample water can be applied without using cleaning water. The consumption can be reduced.

   In order to simplify the program, in the flowchart shown in FIG. 4, the procedure for determining whether or not the elapsed time from the previous conductivity measurement end date and time in step S2 has not exceeded a predetermined threshold is omitted. It doesn't matter. That is, in step S1 of FIG. 4, the previous measurement determination unit 112 of the control device 100 shown in FIGS. 2 and 3 reads the data stored in the data storage unit 101, and whether or not the previous measurement was a conductivity measurement. Determine. If it is determined in step S1 that the previous measurement was a conductivity measurement, the process proceeds directly to step S31, and the sampling channel may be washed n times with sample water.

  Hereinafter, in the case where the cleaning water 17 made of pure water is filled in a 2 L capacity poly tank and connected to the fourth port of the flow path switching means 9, the water sampling flow path according to the embodiment of the present invention is cleaned. An example of the method will be described (in the following example, the determination procedure in step S2 in the flowchart shown in FIG. 4 is omitted).

Example 1
When the previous measurement was conductivity measurement, the conductivity measurement was performed with 1 mL of sample water sucked into the syringe of step S312 in FIG. 5 and n of step 316 being 3.

(Example 2)
If the previous measurement was a TOC measurement, 1 mL of washing water to be sucked into the syringe of step S412 in FIG. 7, a = 4 of step S415, 4 mL of washing water to be sucked into the syringe of step 422, step Conductivity measurement was performed with the ventilation time of 424 as 1 second, b = 3 in step S427, 1 mL of washing water sucked into the syringe in step S432, and c = 3 in step S436.

  In the case of Example 1, the measurement time was shortened by about 4 minutes compared to Example 2, and the consumption of washing water could be reduced by 16 mL.

(Other embodiments)
Although the present invention has been described according to the above-described embodiments, the description and the drawings that constitute a part of this disclosure do not limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art. Therefore, it is needless to say that the present invention includes various embodiments and examples which are not described herein. Accordingly, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

  The present invention can be used in the field of pure water analyzers such as pharmaceutical pure water and semiconductor manufacturing pure water.

DESCRIPTION OF SYMBOLS 1 ... Autosampler 1a ... Sampling needle 2 ... Pure water analyzer 3 ... Measuring part 3 ... TOC measuring part 5 ... Carrier gas supply part 7 ... Conductivity measuring part 9 ... Channel switching means 11 ... Sampling syringe 13 ... Offline sample water DESCRIPTION OF SYMBOLS 15 ... Dilute hydrochloric acid 17 ... Washing water 18 ... Plunger 19 ... Reactor 19 ... IC reactor 19a ... IC reaction liquid 21 ... Drain for discharge 23 ... Carrier gas inlet 25, 37 ... Solenoid valve 27 ... Pressure regulating valve 29 ... Pressure gauge 31 ... Mass flow controller 33 ... Flow meter 35 ... Humidifier 41 ... TC combustion furnace 41a ... TC combustion tube 41b ... TC combustion catalyst 43 ... Sample water injection part 45 ... Check valve 47 ... Cooling tube 49 ... Backflow prevention trap 51 ... Dehumidification electron Cooler 53 ... IC reaction liquid reservoir 55 ... Pump 57 ... Drain solenoid valve 59 ... Drain pot 61 ... Halogen Kuraba 63 ... Membrane filter 65 ... optical system tandem cell 67 ... light source 69 ... detector 71 ... CO ₂ absorber 72 ... conductivity measuring cell 73a, 73b ... platinum electrode 74 ... voltmeter 80 ... plunger drive motor 90 ... multi-valve drive Motor 100 ... Control device 101 ... Data storage means 102 ... Program storage means 110 ... Calculation device 111 ... Data input means 112 ... Previous measurement determination means 113 ... Elapsed time determination means 114 ... Washing frequency determination means 115 ... Switch control means 116 ... Sampling Syringe control means 117 ... carrier gas supply control means 118 ... conductivity measurement control means 119 ... sampling syringe control means 119 ... conductivity calculation means 120 ... TOC measurement control means 121 ... TOC value calculation means 130 ... interface (I / F)
131 ... Plunger drive circuit 132 ... Conductivity measuring device drive circuit 133 ... Multi-valve drive motor drive circuit 134 ... Solenoid valve drive circuit 135 ... TOC measurement device drive circuit 136 ... Carrier gas supply device drive circuit 200 ... Input device 300 ... Output device p ₁ ... 1st flow path p ₂ ... 2nd flow path p ₃ ... 3rd flow path p ₄ ... 4th flow path p ₅ ... 5th flow path p ₆ ... 6th flow path p ₇ ... 7th flow path p ₈ ... 8th flow path p ₉ ... Common flow path

Claims (6)

A sampling channel including a plurality of channels passing through the channel switching unit and a sampling syringe for collecting sample water of a pure water analyzer that switches between TOC measurement and conductivity measurement using a channel switching unit Cleaning method,
Whether the previous measurement determination unit included in the control device included in the pure water analyzer reads the content of the previous measurement performed from the data storage unit of the control device, and whether the previous measurement performed by the pure water analysis device is a TOC measurement. Automatically determining whether it is a conductivity measurement;
In accordance with the determination result, the switching control means and the cleaning frequency determination means of the control device automatically change the cleaning content and the cleaning frequency of the water sampling flow path,
A cleaning method comprising: When it is determined that the previous measurement is a conductivity measurement, the elapsed time determination unit of the control device reads the end date and time of the previous conductivity measurement from the data storage unit, and the elapsed time from the end date and time to the present Calculating a time;
The elapsed time determining means determining whether the elapsed time is within a threshold; and
When the elapsed time exceeds the threshold, the cleaning frequency determination means increases the cleaning frequency compared to when the elapsed time is within the threshold;
The cleaning method according to claim 1, further comprising:   When it is determined that the previous measurement is a TOC measurement, the switching control unit and the cleaning frequency determination unit perform cleaning of the sampling channel, cleaning with cleaning water a plurality of times, and aeration cleaning with the cleaning water a plurality of times. The cleaning method according to claim 1, wherein the cleaning with the sample water is sequentially performed a plurality of times. A TOC measuring unit for measuring the TOC of the sample water, a conductivity measuring unit for measuring the conductivity of the sample water, a flow path switching means for switching a flow path to the TOC measuring unit and the conductivity measuring unit, Before introducing the sample water into the TOC measurement unit, the sampling water is collected, and a sampling syringe for performing an aeration process for discharging inorganic carbon in the sample water as CO ₂ from the sample water, and the TOC A pure water analyzer comprising a measurement unit, the conductivity measurement unit, the flow path switching means, and a control device for controlling the operation of the sampling syringe, wherein the control device is
Data storage means for recording the content of the previous measurement performed by the pure water analyzer;
Previous measurement determination means for reading the content of the previous measurement from the data storage means and determining whether the previous measurement is a TOC measurement or a conductivity measurement;
In accordance with the determination result, a switching control means for changing the washing contents of the water sampling flow path including the plurality of flow paths and the sampling syringe via the flow path switching means,
A pure water analyzer, comprising: a cleaning frequency determination unit that changes the frequency of cleaning the sampling channel according to the determination result. The control device reads an end date / time of the previous conductivity measurement from the data storage means, calculates an elapsed time from the end date / time to the present, and determines whether the elapsed time is within a threshold value A determination unit;
The said washing | cleaning frequency determination means increases the said frequency | count of washing | cleaning compared with the case where the said elapsed time is less than the said threshold value when the said elapsed time exceeds the said threshold value. Pure water analyzer.   When it is determined that the previous measurement is a TOC measurement, the switching control unit and the cleaning frequency determination unit perform cleaning of the sampling channel, cleaning with cleaning water a plurality of times, and aeration cleaning with the cleaning water a plurality of times. 5. The pure water analyzer according to claim 4, wherein the cleaning with the sample water is sequentially performed a plurality of times.

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