JP3973190B2 - Online analyzer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to water quality measurement using a high performance liquid chromatograph, and more particularly to an on-line analyzer that improves reliability and measurement accuracy.
[0002]
[Prior art]
FIG. 2 is a block diagram showing a conventional example of an on-line analyzer. In the figure, a portion surrounded by a one-dot chain line A is a sample pretreatment unit, a gate valve 1 for introducing the sample, a sand filter 2 for filtering the sample, and a hollow fiber membrane for filtering the sample filtered by the sand filter 2 The filter 3 includes a pressure reducing valve 4 for introducing cleaning water, a hollow fiber membrane filter 3a for filtering the cleaning water, a gate valve 5, a first switching valve 6 for switching the flow direction of the sample and the cleaning water, and the like.
[0003]
The portion surrounded by the alternate long and short dash line B is an analysis unit, and the second switching valve 10 for switching the sample and the standard solution stored in the first tank 11, and the sample or the standard solution from the second switching valve 10 are the first and second. The first sample pump 14a to be sent to the sample valves 13 and 16 and the column cleaning liquid stored in the second tank 12 were stored in the third tank 15 and the cleaning pump 14b to be sent to the first and second sample valves 13 and 16, respectively. An eluent pump 14c for sending the eluent to the second sample valve 16 and a thermostatic chamber 21 surrounded by a one-dot chain line.
[0004]
The thermostatic chamber 21 contains a separation column 22, an analyzer 23, and the like. A drain pipe 30 discharges the sample, standard solution, washing water, column washing solution, and eluent discharged from points a to d. The operations of the gate valve 5, the switching valves 6, 10, and the first and second sample valves 13, 16 are controlled by a programmable controller (not shown).
[0005]
In the above configuration, the first switching valve 6 of the sample pretreatment unit A allows only the sample to pass to the analysis unit B side in the normal mode. And in the backwash mode performed every predetermined time progress, the gate valve 5 is opened and wash water is introduced through the hollow fiber membrane filter 3a, and the sand filter is passed through the first switching valve 6 and the hollow fiber membrane filter 3. allowed to flow back to the 2 side inversely washed solids stick to a hollow fiber membrane filter 3. At the same time, washing water is also introduced from the valve BV2 and the sand filter 2 is backwashed.
[0006]
The first sample valve 13 on the analysis unit B side is usually configured to pass the sample filtered by the sand filter 2 through the sample pump 14a (indicated by a dotted line). It is drained through 6 routes. Further, the column cleaning liquid is drained by the cleaning pump 14b through the first sample valve 13 through 3 → 4 → the measuring tube 13a → 1 → 2 and through the second sample valve 16 through 3 → 4 → concentration column 17 → 1 → 2. Yes.
[0007]
In the sample collection mode, the valve of the first sample valve 13 is switched (to the solid line side), and the sample is discharged via 5 → 4 → metering tube 13a → 1 → 6. During this time, the column cleaning liquid is discharged through 3 → 2 of the first and second sample valves. When the first and second sample valves are switched to the dotted passage after a predetermined time has elapsed, the sample is transferred to the column washing liquid, and the first sample valve 13 3 → 4 → metering tube 13 → 1 → 2 → second sample valve It is discharged through 3 → 4 → concentration column 17 → 1 → 2. During this time, the eluent stored in the third tank 15 is discharged through the analyzer 23 including the separation column 22 through the second sample valve 16 through 5 → 6 via the eluent pump.
[0008]
When the predetermined time further elapses, the second sample valve 16 is switched to the solid line side, and the eluent goes through the second sample valve 16 through the 5 → 4 → concentration column 17 → 1 → 6 and the analyzer 23 including the separation column 22 side. To be discharged. At this time, the eluent transports the measurement component accumulated in the concentration column 17 to the separation column 22 side and is analyzed by the analyzer 23.
In the calibration mode, the second switching valve 10 is made to flow a standard solution instead of a sample, and calibration is performed according to the above-described procedure.
[0009]
[Problems to be solved by the invention]
By the way, when measuring a river water etc. in an on-line analyzer, if a sample is directly introduced into the analyzer 23, a column etc. will be obstruct | occluded by a suspended matter. Therefore, conventionally, pretreatment (filtration) is performed using a sand filter 2 and a hollow fiber membrane filter 3 as shown in FIG. However, when measuring an extremely low concentration anionic surfactant contained in river water, if the hollow fiber membrane 3 is used as a filter, the measurement component is adsorbed by the hollow fiber membrane filter 3 and there is a problem in responsiveness and measurement accuracy. is there.
[0010]
Further, in order to confirm that the sample water has flowed out to the analyzer 23 side, conventionally, a liquid breakage detection means comprising a liquid breakage detection tank 27 and a throttle 28 is provided downstream of the sand filter 2. In the figure, while a predetermined amount of sample is being supplied from the sand filter 2, the sample is restricted by the throttle 28 and flows toward the liquid shortage detection tank. The sample overflows from a predetermined position provided in the liquid shortage detection tank 27 and is discharged to the discharge pipe side.
[0011]
Here, when the sample is reduced due to clogging of the sand filter 2 or the like, the sample is not supplied to the liquid draining tank 27 side, so the water level is lowered. This drop in water level can be monitored to take measures against sample shortage.
However, parts such as a pipe, a pump, and a sample valve are interposed from the preprocessing unit to the analyzer, and there is a possibility that the sample may not be sufficiently sent to the analyzer 23 due to a problem. That is, there is a possibility that it may be judged that the concentration is low even though the sample is substantially insufficient, and there is a possibility that a problem in measurement accuracy may occur.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an on-line measurement apparatus that improves the reliability of measurement accuracy.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides, in claim 1,
A concentration tube provided in the first sample valve and a concentration column disposed in the latter stage of the first sample valve and provided in the middle of the pipe connecting the connection ports of the second sample valve to the sample measured by the measurement tube An on-line analyzer comprising a detector for capturing and concentrating, injecting the analyte to be captured and concentrated with an eluent into a separation column, and detecting the separated analyte, wherein the sample is the first in the normal mode. The sample is discharged without passing through the metering tube of the sample valve, and in the sample collecting mode, the sample measured by the metering tube of the first sample valve is sent to the analyzer side through the concentration column of the second sample valve. In the on-line analyzer, the monitoring means for monitoring the presence or absence of the sample flowing through the measuring pipe and the pipe connecting the connection ports of the second sample valve are arranged in front of each other. Rutotomoni provided an in-line filter less adsorption upstream of the concentration column for anionic surfactants, the monitoring means provided downstream of said metering tube, diaphragm, is composed of a pressure sensor and the damper tube, a predetermined An alarm transmission function is provided when the pressure drops below the pressure .
[0014]
In the present invention, the hollow fiber membrane filter 3 provided between the sand filter 2 and the first switching valve 6 is removed in the middle of the pipe connecting the connection port 4 of the second sample valve 16 and the concentration column 17 instead. Install the inline filter 26.
[0015]
That is, the sample captured in the measuring tube 13 in the sample measurement mode is transported by the column cleaning liquid and discharged through the connection port 4 → 5 → inline filter 26 → concentration column 17 of the second sample valve 16, but the measurement component ( Here, the anionic surfactant) does not pass through the hollow fiber membrane, and therefore is concentrated in the concentration column 17 without being attenuated.
Next, the concentrated component is conveyed by the eluent through the path switched to the solid line side, sent to the separation column 22 side, and analyzed for each separated component by the analyzer.
[0016]
Next, claim 2 of the present invention will be described.
In the present invention, a throttling 25, a pressure sensor 24, and a damper tube 27 are provided on the downstream side of the measuring tube 13a as a liquid breakage detecting means. The damper tube 27 serves to suppress pulsation and make it easy to read instructions. In addition, a pressure sensor shall have an alarm transmission function, when it falls below a predetermined pressure.
[0017]
In the figure, a throttle 25 is provided. This throttle can be adjusted by adjusting the inner diameter and length of the pipe from the pressure sensor 24 to the drain, and the thickness and length of the throttle 25 Determined by the properties of
[0018]
According to the above-described configuration, since it is possible to monitor that the sample has truly passed through the measuring tube, it is possible to ensure the complete measurement and to prevent the generation of inaccurate measurement values.
[0019]
The foregoing description of the present invention has only shown certain preferred embodiments for purposes of illustration and illustration. It will be apparent to those skilled in the art that the present invention can be modified and modified in many ways without departing from the essence thereof.
The scope of the present invention defined by the description in the appended claims is intended to include modifications and variations within the scope.
[0020]
【The invention's effect】
According to the invention of claim 1 as specifically described above with reference to the embodiments, the measuring pipe provided in the first sample valve and the sample measured by the measuring pipe are arranged at the subsequent stage of the first sample valve. Capturing and concentrating with a concentration column provided in the middle of the pipe connecting the connection ports of the second sample valve, injecting the captured and concentrated analyte with the eluent into the separation column, and detecting the separated analyte An on-line analyzer comprising a detector, wherein the sample is discharged without passing through the metering tube of the first sample valve in the normal mode, and the sample measured by the metering tube of the first sample valve is sampled in the sample collection mode. Monitoring means for monitoring the presence or absence of a sample flowing through the measuring tube in an on-line analyzer configured to be sent to the analyzer side via the concentration column of the second sample valve; The second sample valve connection port between a middle of the pipe connecting provided an in-line filter less adsorption to the anionic surfactant in front of the concentration column Rutotomoni, said monitoring means downstream of the metering tube It is equipped with a throttle, a pressure sensor and a damper tube, and has an alarm transmission function when it falls below a predetermined pressure, so that it is possible to make a perfect measurement and prevent the generation of inaccurate measurement values It is possible to realize an on-line analyzer that can do this. Further, when measuring an extremely low concentration anionic surfactant contained in river water, the measurement component can be concentrated in the concentration column 17 without attenuation. As a result, online analysis with high responsiveness and high measurement accuracy is possible.
[Brief description of the drawings]
FIG. 1 is a configuration explanatory diagram showing an example of an embodiment of an on-line analyzer of the present invention.
FIG. 2 is a configuration explanatory view showing an example of a conventional online analysis device.
[Explanation of symbols]
A Sample pretreatment part B Analysis part 1, 4, 5 Gate valve 2 Sand filter 3, 3a Hollow fiber membrane filter 6 1st switching valve 10 2nd switching valve 11 1st tank 12 2nd tank 13 1st sample valve 13a Metering tube 14a Sample pump 14b Wash pump 14c Eluent pump 15 Third tank 16 Second sample valve 17 Concentration column 21 Thermostatic chamber 22 Separation column 23 Analyzer 24 Pressure sensor 25 Restriction 26 In-line filter 27 Damper tube 30 Drain tube
.

Claims (1)

A concentration tube provided in the first sample valve and a concentration column disposed in the latter stage of the first sample valve and provided in the middle of the pipe connecting the connection ports of the second sample valve to the sample measured by the measurement tube An on-line analyzer comprising a detector for capturing and concentrating, injecting the analyte to be captured and concentrated with an eluent into a separation column, and detecting the separated analyte, wherein the sample is the first in the normal mode. The sample is discharged without passing through the metering tube of the sample valve, and in the sample collecting mode, the sample measured by the metering tube of the first sample valve is sent to the analyzer side through the concentration column of the second sample valve. In the on-line analyzer, the monitoring means for monitoring the presence or absence of the sample flowing through the measuring pipe and the pipe connecting the connection ports of the second sample valve are arranged in front of each other. Rutotomoni provided an in-line filter less adsorption upstream of the concentration column for anionic surfactants, the monitoring means provided downstream of said metering tube, diaphragm, is composed of a pressure sensor and the damper tube, a predetermined An on-line analyzer characterized by having an alarm transmission function when the pressure drops below the pressure .

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