JP4673197B2 - Liquid sample monitoring method and liquid sample analyzer - Google Patents

Description

  The present invention relates to a monitoring technique for liquid samples, particularly water quality monitoring related to the environment such as rivers and groundwater, water quality monitoring related to engineering equipment such as chemical synthesis equipment, culture equipment, water purification equipment, nuclear power equipment, etc. The present invention relates to a liquid sample monitoring method and monitoring system.

  Monitoring for liquid samples is performed in various fields, for example, water quality monitoring for evaluating the environment such as rivers, lakes, dams, groundwater, engineering facilities such as chemical synthesis, culture, water purification, and nuclear power. Water quality monitoring is conducted for the purpose of reaction control and detection of water quality abnormalities.

  Conventionally, in such monitoring, a method of analyzing a liquid sample with a sensor in situ (see Patent Document 1), or a method of analyzing by collecting a part of the liquid sample and sending it to an analyzer (Patent Document 2) Reference) is used.

JP 2000-121629 A JP 2005-66531 A

  In the method of analyzing a liquid sample as described above with a sensor on the spot, it is possible to construct a monitoring system with a small size and low cost, but there are restrictions on the type of sensor, such as temperature, pH, ORP, conductivity, Only general water quality tests such as turbidity, dissolved oxygen, and ultraviolet absorbance are applicable, and there are problems such as restrictions on the measurable concentration range.

  On the other hand, in the method of analyzing by collecting a part of the liquid sample and sending it to the analyzer, it is possible to cope with the analysis of various components and the concentration range, but the apparatus becomes larger and differs depending on the monitoring system. Since an analyzer is required, there is a problem that the equipment cost increases.

  An object of the present invention is to provide a liquid sample monitoring method and a monitoring system that are compatible with various analysis items and concentration ranges, and are small and low cost.

  The above problem is that, for example, by injecting a part of the liquid sample to be monitored continuously into the one-dimensional channel at a constant flow rate or at regular intervals, the time change of the liquid sample property is injected into the channel. This is solved by analyzing the held liquid sample for each position of the flow path and reproducing the time change of the liquid sample properties from the analysis result.

  The present invention is based on the finding that a temporal change in water quality can be stored as position information in a one-dimensional channel.

  When a liquid sample is injected into a one-dimensional channel at a constant flow rate, the sample flows as a stable laminar flow in the channel, and mixing of water quality components due to turbulence or the like is suppressed. In addition, since the channel cross-sectional area is small, mixing due to diffusion with adjacent parts is also suppressed.

  Accordingly, it is possible to divide the monitoring of the liquid sample into sampling into a one-dimensional flow path and analysis for each flow path position. This makes it possible to use a small and low-cost device configuration for sampling a liquid sample, and for analysis, a one-dimensional flow path such as a tube containing a solution sample is used for various analytical instruments as required. It is possible to connect to and continuously analyze, and to share and use the same analytical instrument for multiple monitoring.

  In addition, if there is a record of the injection time, injection speed, etc. of the liquid sample, the analysis result for each position in the flow path can be easily converted into a time change.

  From the viewpoint of downsizing the apparatus, it is preferable to spatially increase the density of the one-dimensional channel, but the easiest way to achieve this is to wind up the channel such as a tube in a bobbin shape. Is achieved.

  In order to perform analysis in the sampled flow channel in a timely manner, it is effective to provide a mechanism that can be switched to the flow channel for injecting the liquid sample, and a detachable mechanism. It becomes possible to obtain an analysis result in a period.

  From the viewpoint of improving the accuracy and reliability of monitoring, the effect of suppressing the mixing of water quality components between adjacent parts in the flow path by adding marker substances etc. to the flow path for storing solution samples at regular intervals In addition, an effect of easily confirming visually that the liquid sample is appropriately injected by the pump can be expected. Furthermore, when this marker substance is a bubble, mixing of water quality components can be almost eliminated, and this is an extremely effective method for long-term monitoring and the like.

  According to the present invention, it is possible to cope with various analysis items and concentration ranges in monitoring of a liquid sample. In addition, downsizing of the apparatus, improvement of data reliability, and reduction of monitoring costs can be achieved.

  Before describing embodiments of the present invention, the basic principle leading to the present invention will be described. The present invention is based on the finding of the inventor that a temporal change in water quality can be stored as position information in a one-dimensional channel. Below, the concept of storing the temporal change in water quality as position information in the present invention will be described with reference to FIG.

The inventors collect a part of the liquid sample whose water quality component concentration is known in advance with a pump, and have a flow rate cross-sectional area of 0.1 cm ² at a flow rate of 10 cm ³ / h. It inject | poured continuously into the tube which is a flow path. After that, as a result of analyzing the liquid sample for each tube position, the graph of the water quality change in position is symmetrical with respect to the time change of the water quality and the Y axis. We found that the temporal change in water quality can be reproduced.

  This is because the liquid sample was injected into the one-dimensional channel at a constant flow rate, so that the sample flowed as a stable laminar flow in the channel, and the mixing of water quality components due to turbulent flow was suppressed. It is done. In addition, since the cross-sectional area of the flow path is small, it is considered that there is an effect of suppressing mixing due to diffusion with adjacent parts.

  By continuously injecting and collecting a liquid sample into a tube that is a one-dimensional flow path, the liquid sample monitoring process can be divided into a sampling process into a one-dimensional flow path and an analysis process for each flow path position. It becomes possible to divide. As a result, the apparatus used for the sampling process of the liquid sample can be configured to be small and low-cost, and for the analysis process, a one-dimensional flow path such as a tube containing the solution sample is provided as necessary. It is possible to increase the degree of freedom by connecting to various analytical instruments for continuous analysis and sharing the same analytical instrument for use in multiple monitoring.

  The one-dimensional flow path is a flow path that can be estimated to be a sufficiently laminar flow without taking the turbulent flow in consideration of the flow velocity of the liquid and the cross-sectional area of the flow path. The Reynolds number Re is represented by the following equation.

  Re = (U × L) / ν

Here, U is a representative speed, L is a representative length, and ν is a kinematic viscosity coefficient. For example, in Example 2 below, assuming that the liquid is water, U is 10 cm ³ / h, the diameter of the flow path is 1 cm, and L is 3.5 m. It is sufficiently smaller than 2000 which is the Reynolds number Re. Therefore, it is estimated that the liquid is a laminar flow and is a one-dimensional flow path. The same applies to the other embodiments.

  Hereinafter, a liquid sample monitoring technique according to an embodiment of the present invention will be described with reference to the drawings.

  A liquid sample monitoring technique according to Embodiment 1 of the present invention will be described with reference to FIG. The liquid sample monitoring technique according to this embodiment will be described based on an example of monitoring the water quality of a river or the like. The liquid sample monitoring technique according to the present embodiment includes a process of collecting a liquid sample and a process of analyzing the liquid sample.

  As shown in FIG. 1, the liquid sample monitoring system according to this embodiment includes, in order from the liquid sample 1 side, a filter unit 3, a pump 2, a valve 4, a sample storage channel 5, a valve 6, have.

In the sampling process of the liquid sample 1 (upper figure), the liquid sample 1 is sucked by the pump 2 and passed through the filter unit 3 to exclude fine particles, and then forms a one-dimensional flow path through the valve 4. Inject into the storage channel 5. At this time, the valve 4 and the valve 6 are opened. The pump 2 continuously sent the liquid sample 1 to the sample storage channel 5 at a flow rate of 1 cm ³ / h for about one week. For the sample storage channel 5, a tube wound in a plurality of times in a wound form having a diameter of 6 mm and a length of 6 m was used.

  Next, in the analysis process of the liquid sample (below), after collecting the liquid sample 1, the sample storage flow path 5 was transferred to a place for analysis with the valve 4 and the valve 6 closed. Thereafter, the water quality analyzer 7 was connected via the valve 6. Thereafter, the valve 4 and the valve 6 are opened, and the pure water 8 is fed from the filter unit 3 side to the sample storage channel 5 using the pump 2, and the liquid sample stored in the sample storage channel 5 is transferred to a predetermined sample. Each quantity corresponding to the length of the storage channel was transferred to the water quality analyzer 7 for water quality analysis.

FIG. 3 shows the results of water quality analysis for each sample storage channel length of 8.49 cm (liquid amount 2.4 cm ³ ). In the upper diagram, the vertical axis represents the water quality component concentration, and the horizontal axis represents the position in the one-dimensional flow path.The lower graph represents the water quality component concentration on the vertical axis and the elapsed time since the liquid sample was inhaled on the horizontal axis. I'm taking it. From this result, according to the present example, it can be seen that the time change of the water quality of the liquid sample is stored as the position change in the sample storage channel 5. In other words, the water quality sampling time at each position in the sample storage channel 5 shown in the above figure can be obtained from the water quality sampling time = flow velocity / channel cross-sectional area. Therefore, the graph obtained by converting the graph obtained as the position change of the water quality into the time change of the water quality is shown below. From this result, the liquid sample could be monitored.

  The system according to this embodiment has a simple apparatus and can be miniaturized. In particular, when the pump can be installed at a remote location, monitoring is possible if only the flow path space for collecting the liquid sample can be secured. Therefore, it is usually difficult to monitor narrow spaces, high temperatures, high pressures, radiation. It is also easy to use in extreme environments such as Noh.

  In addition, since it is possible to separate the collection and analysis of the liquid sample, it is possible to share a plurality of collected samples, for example, in a single analyzer when performing a plurality of monitoring, etc. There is an advantage that the equipment cost can be reduced. Further, the analysis process has an advantage that it can cope with the analysis of various components and the concentration range by connecting the collected sample to the most appropriate analyzer as necessary.

  In addition, it is preferable to use the pump which can control micro flow volume, such as a plunger pump, a syringe pump, and a tube pump, as a pump. Analytical devices include ion chromatography, liquid chromatography, gas chromatography, ICP emission analyzer, atomic absorption analyzer, total organic carbon concentration meter, mass spectrometer, etc. Is suitable.

  Next, a liquid sample sampling technique according to the second embodiment of the present invention will be described with reference to FIG. As shown in FIG. 4, this example is an example when water quality is monitored in a reaction tank in which chemical synthesis is performed. In this embodiment, a part of the liquid sample in the reaction tank 9 is collected by the sample collection device 10 and injected into the sample storage device 11. The sample collection device 10 includes a filter 12, a pump 13, a valve 14, and a recording device S therein. The sample storage device 11 includes a sample storage flow path 16 and valves 17 and 18 provided before and after the sample storage flow path 16. A well-known attachment / detachment mechanism 15 capable of connecting / separating a pipe is provided at a connection portion between the sample collection device 10 and the sample storage device 11. As for the operation of the pump 13, the recording device S controls the injection time and the injection speed of the liquid sample into the flow path, whereby position information that can be converted into time information is recorded in the sample storage flow path 16. It is a mechanism. The recording device S records the injection time and injection speed of the liquid sample into the flow path.

A part of the liquid sample is sucked by the pump 13 through the filter 12 and injected into the sample storage channel 16 at a constant flow rate. At this time, the valve 14, the valve 17 and the valve 18 are opened, and the liquid sample injection start time and injection speed can be recorded in the recording device S. The pump 13 continuously sent the liquid sample into the sample storage channel 16 at a flow rate of 10 cm ³ / h for 24 hours. For the sample storage channel 16, a tube having a diameter of 1 cm and a length of 3.5 m was used.

  When the sample storage channel 16 is very long, handling may be difficult. In such a case, a sample storage channel in which a tube T as shown in FIG. 5 is wound in a bobbin shape can also be used. Thereby, the volume occupied by the sample storage channel 16 can be significantly reduced, and the monitoring device can be further downsized. Further, it also has a function of maintaining the shape of the sample storage channel 16.

  After the liquid sample was collected over 24 hours, the storage capacity of the sample storage device 11 became full. Therefore, the liquid supply from the pump 13 was stopped once, the valve 14, the valve 17, and the valve 18 were closed. In part, the sample storage device 11 was removed from the sample collection device 10, and another new sample storage device (11) was mounted. Thereafter, the closed valves 14, 17 and 18 were opened again, and the operation of the pump 13 was started again.

  On the other hand, as shown in the lower diagram of FIG. 4, the collected sample storage device 11 sends pure water 20 by another pump 19, and the liquid sample stored in the sample storage channel 16 is the fraction collector 21. Thus, fractionation was performed by an amount corresponding to a predetermined sample storage channel length. Thereby, a measurement sample is produced and it can analyze for every sample.

  The analysis results obtained in this way are the results of water quality analysis for each position of the sample storage channel 16, and these are the injection time and injection rate of the liquid sample recorded in the recording device S. From the data, convert to the time change of the original liquid sample. Thereby, monitoring of a liquid sample can be implemented.

  In the liquid sample sampling technique according to this embodiment, the sample collection device 10 and the sample storage device 11 can be divided by the attachment / detachment mechanism 15. Since the sample storage device 11 can be attached and detached, it is characterized in that long-term monitoring can be performed while replacing the sample storage device 11 with a new one.

  Further, when monitoring a plurality of reaction tanks, for example, one analyzer can be shared and used. In addition, since the sample to be analyzed is fractionated for each position of the sample storage flow path 16 by the fraction collector 21, it can be applied to an analysis method that cannot be directly connected to an analytical instrument, and a wider range of analysis methods There is an advantage that an appropriate method can be selected from among the methods.

  Next, a liquid sample monitoring technique according to Embodiment 3 of the present invention will be described with reference to FIG. The present embodiment is an example when water quality is monitored in the piping of nuclear facilities.

  The liquid sample monitoring system according to the present embodiment has a configuration in which a part of the liquid sample in the pipe 22 is collected by the sample collection device 23 and injected into the sample storage channel 50-1. The sample collection device 23 includes a filter 24, a first pump 25, a flow path switching mechanism 26, a second pump 27, and a marker substance tank 28 from the piping 22 side. The first pump 25, the flow path switching mechanism 26, and the second pump 27 are mechanisms whose operation is controlled by the control device 29. The flow path switching mechanism 26 can use a known mechanism such as a rotary input-output switching mechanism so that a plurality of output positions correspond by rotating with respect to one input position.

  The control device 29 operates the first pump 25 at a predetermined time, collects a part of the liquid sample via the filter 24, and injects it into the sample storage channel 50 at a constant flow rate. At the same time, the control device 29 controls the second pump 27 to add the marker substance into the flow path at regular time intervals.

  After collecting the sample for a certain period of time, the first pump 25 and the second pump 27 are stopped by the controller 29, and the collection of the sample and the addition of the marker substance are interrupted. Thereafter, the first pump 25 and the second pump 27 were operated again by the control device 29 at a predetermined time, and the sample was collected and the marker substance was added. At this time, a colored solution was used for the marker substance so as to be visible.

  As described above, after the continuous operation of repeating the sampling and interruption of the sample is performed, the flow switching mechanism (valve) 26 is operated by the control device 29, and the sample storage flow channel 50-1 is separated before the storage capacity is exceeded. Switch to the sample storage channel 50-2 or 50-3 of the system.

  The sample storage channel 50-1 storing the sample is disconnected from the sample collection device 23 after the valve 30-1 and the valve 31-1 are closed, and transferred to the analysis chamber. Thereafter, as shown in the figure below, the sample storage channel 50-1 is extended, and the radioactivity at each position can be measured by the radiation detector 34 through the measurement hole 33 provided in the shielding plate 32. The measurement result is converted into the time change of the original liquid sample from the operation record of the control device 29 and the number and position of the marker substances. Thereby, the liquid sample could be monitored.

  By using the liquid sample monitoring technology according to the present embodiment, automatic operation by the control device is possible, and furthermore, by collecting the liquid sample at regular time intervals, the measurement time is longer than when collecting the liquid sample continuously. Can be shortened. Further, by providing a flow path switching mechanism, it is possible to obtain an analysis result in an arbitrary period while continuing monitoring.

  In addition, from the viewpoint of improving the accuracy and reliability of monitoring, mixing of water quality components between adjacent parts in the flow path is suppressed by adding a marker substance every time in the flow path for storing the solution sample. In addition, the confirmation of the injection position of the liquid sample can be simplified by visual observation or the like. As the marker substance, various substances that can be easily analyzed, such as a solution containing a fluorescent substance and a colored solution, can be used. For example, a fluorescent substance may be used as the marker substance, and this may be detected by a fluorescence detector. Alternatively, a material having a refractive index that is significantly different from that of the solution sample may be used as the marker material, and the solution sample and the marker material may be distinguished from each other by a combination of a light source and a light amount sensor. Alternatively, a gas such as an inert gas may be used as the marker substance. By using such a marker substance, the analysis time can be arbitrarily divided, so that the work can be easily automated.

  Further, according to the present embodiment, even if sampling is not always performed, for example, a liquid sample is sampled at a certain time using a timer or the like, then a marker substance is injected, and sampling is interrupted for a certain time, and then again. It is also possible to carry out the step of starting sampling.

  A liquid sample monitoring technique according to Embodiment 4 of the present invention will be described with reference to FIG. The liquid sample monitoring technique according to the present embodiment is an example of water quality monitoring in the geological borehole.

  In the liquid sample monitoring technique according to the present embodiment, a part of the liquid sample in the formation 35 is collected by the sample collection device 36 and injected into the sample storage channel 37. These devices are inserted into a boring hole having a diameter of about 10 cm, for example. The sample collection device 36 has a groundwater collection mechanism 38, a filter 39, a first pump 40, a gas cylinder 41, and a second pump 42 in that order from the formation 35 side. A control device 43 for controlling the first pump 40 and the second pump 42 is provided, and the operation is controlled by this.

  The control device 43 operates the first pump 40 at a predetermined time, collects a part of the liquid sample via the filter 39, and injects it into the sample storage channel 37 at a constant flow rate, for example. At the same time, the second pump 42 is controlled by the control device 43 so as to add, for example, bubbles made of an inert gas into the flow path at regular time intervals. After continuous operation for a predetermined time, the operation of the first pump 40 and the second pump 42 is stopped by the control device 43, and the liquid sample recovery step and the bubble addition step are terminated.

  Thereafter, as shown in the figure below, the sample storage channel 37 is recovered from the borehole to the ground and connected to the water quality analyzer 46 via the valve 45. Next, the valve 44 and the valve 45 are opened, the pure water 48 is sent to the sample storage channel 37 using a new pump 47, and the liquid sample stored in the sample storage channel 37 is transferred to a predetermined sample storage channel. Each quantity corresponding to the length is transferred to the water quality analyzer 46 to perform water quality analysis.

  The analysis result obtained here is a water quality analysis result for each position of the sample storage channel 37. The liquid sample can be monitored by converting these into the time change of the original liquid sample based on the data of the injection time and the injection speed of the liquid sample set by the control device 43.

  According to the present embodiment, since the sample collection process and the analysis process can be performed separately, the apparatus can be easily downsized and can be applied to monitoring in a narrow boring hole. In addition, by adding bubbles, the bubbles in the flow path suppress the mixing of the liquid sample, so even when the sample storage solution is stored for a long period of time, changes in water quality are accurately stored at each position in the flow path. Has the advantage of. Furthermore, it can be confirmed from the number of bubbles whether the sample has been properly collected. It should be noted that various gases such as air and inert gas can be used as the gas for generating the bubbles.

  As described above, according to the liquid sample sampling technique according to the present embodiment, it is possible to realize a liquid sample monitoring method and monitoring system that can handle various analysis items and concentration ranges, downsizing the apparatus, and data There is an advantage that reliability of the system can be improved and monitoring costs can be reduced.

  The present invention is applicable to a liquid sample sampling system.

It is a figure explaining the monitoring system used for the Example of this invention. It is a figure explaining the concept which stores the time change of the water quality used for explanation of an operation of the present invention as position information. It is a figure explaining the monitoring method used for the Example of this invention. It is a figure explaining the monitoring system used for another Example of this invention. It is a figure explaining the sample storage flow path used for another Example of this invention. It is a figure explaining the monitoring system used for another Example of this invention. It is a figure explaining the monitoring system used for another Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Liquid sample, 2 ... Pump, 3 ... Filter unit, 4 ... Valve, 5 ... Sample storage flow path, 6 ... Valve, 7 ... Water quality analyzer, 8 ... Pure water, 9 ... Reactor, 10 ... Sampling device 11 ... Sample storage device, 12 ... Filter, 13 ... Pump, 14 ... Valve, 15 ... Removal mechanism, 16 ... Sample storage channel, S ... Recording device, 17 ... Valve, 18 ... Valve, 19 ... Pump, 20 ... Pure water, 21 ... fraction collector, 22 ... piping, 23 ... sample collection device, 50 ... sample storage channel, 24 ... filter, 25 ... pump, 26 ... channel switching mechanism, 27 ... pump, 28 ... marker substance tank, DESCRIPTION OF SYMBOLS 29 ... Control apparatus, 30 ... Valve | bulb, 31 ... Valve | bulb, 32 ... Shielding board, 33 ... Measurement hole, 34 ... Radiation detector, 35 ... Formation, 36 ... Sample collection device, 37 ... Sample storage channel, 38 ... Groundwater collection Mechanism 3 ... Filter, 40 ... pump, 41 ... gas cylinder, 42 ... pumps, 43 ... controller, 44 ... valve, 45 ... valve, 46 ... water analysis apparatus, 47 ... pumps, 48 ... purified water.

Claims (3)

A liquid storage channel that forms a one-dimensional channel; a first valve that opens and closes one opening of the liquid storage channel; and a second valve that opens and closes the other opening of the liquid storage channel. A step of reading from the recording device the flow rate and the injection start time recorded in the recording device when the liquid sample is injected into the liquid storage channel through the sample collection device detachably attached to the sample storage device;
Analyzing the liquid sample held in the sample storage device detachably attached to the analysis device after being removed from the sample collection device for each position of the liquid storage channel;
And a step of reproducing the analysis result into a time change of the liquid sample property based on the flow rate and the injection start time. A liquid storage channel that forms a one-dimensional channel; a first valve that opens and closes one opening of the liquid storage channel; and a second valve that opens and closes the other opening of the liquid storage channel. Means for reading from the recording device the flow rate and the injection start time recorded in the recording device when the liquid sample is injected into the liquid storage channel through the sample collection device detachably attached to the sample storage device;
Means for analyzing the liquid sample held in the sample storage device detachably attached to the analysis device after being removed from the sample collection device for each position of the liquid storage channel;
A liquid sample analyzer comprising: means for reproducing an analysis result into a time change of liquid sample properties based on the flow rate and the injection start time. The liquid sample analyzer according to claim 2, wherein the shape of the one-dimensional flow path is a shape obtained by winding a tube.

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