JP2010008113A - Flow injection analyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flow injection analyzer using a general FIA (Flow Injection Analysis) method, capable of reducing cost even when measuring by using a plurality of samples. <P>SOLUTION: In the flow injection analyzer with a channel through which carrier liquid flows, and introduction selector valves for introducing a sample supplied to a sample loop into the carrier liquid, for reacting the sample introduced into the carrier liquid with a reaction reagent, and measuring reaction results, a plurality of introduction selector valves 8a, 8b, 8c, 8d are arranged in series on the channel through which the carrier liquid 1 flows. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a flow injection analyzer that includes an introduction switching valve that introduces a sample into a carrier liquid, causes the carrier liquid into which the sample has been introduced to be mixed and reacted with a reaction reagent, and measures the resulting change in chemical characteristics. .

  As a general flow injection analysis (FIA) method, JIS K0126 general description of flow injection analysis includes “general FIA method”, “inverse FIA method”, “double injection method”, “merging zone” "Method", "Sandwich injection method", "Flow injection titration method" and "Stopped flow method" are described.

  The FIA method includes the double injection method. This double injection method can create two calibration curves with different concentration ranges at the same time as described in JIS K0126 Flow Injection Analysis General Rules, enabling efficient measurement when the concentration range of analysis components is wide. It is. The purpose of the double injection method is to expand the dynamic range of the measured concentration by changing the volume of each of the two sample loops for a sample having a large concentration change.

JIS K0126 Flow Injection Analysis General Explanation

  However, in the double injection method, an apparatus is required for each sample, and the cost increases.

  An object of the present invention is to provide a flow injection analysis apparatus using a general FIA method, which can achieve cost reduction even when measuring using a plurality of samples.

  In order to solve the above problems, the flow injection analyzer of the present invention is characterized in that a sample introduction switching valve is arranged in series on a flow path through which a carrier liquid flows.

  Thereby, when measuring a some sample, it is not necessary to prepare a flow injection analyzer for every sample, and cost reduction can be aimed at.

  In the flow injection analyzer of the present invention, each of the introduction switching valves may simultaneously perform suction of a sample assigned to each introduction switching valve. According to the above configuration, the sample suction time can be shortened. In addition, since the measurement cycle time can be shortened, the consumption of the reaction reagent during measurement can be reduced.

  In the flow injection analyzer of the present invention, it is preferable that each introduction switching valve sequentially introduces a sample into the carrier liquid successively. According to the above configuration, since the sample is sequentially introduced into the carrier liquid successively through the introduction switching valve, the peak can be continuously detected, and the time of the measurement cycle can be shortened. Furthermore, since the measurement cycle time can be shortened, the consumption of the reaction reagent can be reduced.

  In the flow injection analyzer of the present invention, it is preferable to introduce the sample into the carrier liquid in order from the downstream introduction switching valve.

  In the flow injection analyzer of the present invention, it is preferable to stop the introduction of the sample into the other introduction switching valve while the sample is being introduced into any of the introduction switching valves. According to the above configuration, the sample flow path can be shortened because the introduction of the sample into the other introduction switching valve is stopped while the sample is being introduced into one of the introduction switching valves.

  In the flow injection analyzer of the present invention, it is preferable that the volume of the sample loop of each introduction switching valve can be changed according to the concentration of the supplied sample.

  In addition, the flow injection analyzer of the present invention includes a plurality of units, each including an introduction switching valve, a selection switching valve for selecting a sample and a standard solution, and a pump for sucking the sample and the standard solution into the sample loop. Preferably it is.

  According to the present invention, it is possible to provide a flow injection analyzer using a general FIA method, which can achieve cost reduction even when measuring using a plurality of samples.

(Description of configuration)
A flow injection analyzer (present apparatus) showing an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, this apparatus includes a plurality of sample introduction units A, B, C, and D, a carrier liquid pump 2, a reaction reagent pump 4, a thermostat 10, a detector 12, a data processing unit 13, and a control unit. 14 is provided.

  The carrier liquid pump 2 feeds the carrier liquid 1 and the reaction reagent pump 4 feeds the reaction reagent 3.

  Samples 5a, 5b, 5c, 5d and standard solutions 6a, 6b, 6c, 6d can be fed to the sample introduction units A, B, C, D, respectively. The sample introduction unit A includes an introduction switching valve (sample introduction valve) 8a, a selection switching valve 9a for selecting the sample 5a and the standard solution 6a, and a sampling pump 7a. The sampling pump 7a sends the sample 5a or the standard solution 6a selected by the selection switching valve 9a to the introduction switching valve (sample introduction valve) 8a.

  The introduction switching valve 8a has a sample loop 80a. The introduction switching valve 8a is generally a sliding six-way valve, but is not limited to a six-way valve. For example, the introduction switching valve 8a may be a combination of non-sliding three-way solenoid valves. good. The sample loop 80a can adjust the sensitivity by changing the capacity according to the concentration of the sample. For example, for the low concentration sample, the volume of the sample loop 80a is set to 500 μl to minimize the influence of diffusion, and for the high concentration sample, the volume of the sample loop 80a is set to 50 μl to adjust the sensitivity by the dilution effect by diffusion. be able to.

  Here, as the selection switching valve 9a for the sample 5a and the standard solution 6a, a one-flow path six-way switching valve is used, but the switching direction is not limited to six, and the number of switching according to the application good.

  The sampling pump 7a supplies the sample 5a and the standard solution 6a to the sample loop 80a of the introduction switching valve 8a by suction. As this sampling pump 7a, for example, a peristaltic pump can be used.

  The other sample introduction units B, C, and D have the same configuration except that the volume of the sample loop is changed according to the concentration of the sample. As for the number of sample introduction units, one unit is used for one sample, and units can be arranged according to the number of samples. Further, it is possible to measure samples smaller than the number of installed sample introduction units by setting parameters of the control unit 14.

  The carrier liquid 1 is fed by the carrier liquid pump 2. As the carrier liquid pump 2, it is desirable to use a double plunger type pump so as to cope with a decrease in pulsating flow and an increase in discharge pressure due to an increase in the sample introduction unit.

  As the reaction reagent 3, a reaction reagent 3 that is less affected by coexisting substances is selected. The reaction reagent 3 is fed by a reaction reagent pump 4. The reaction reagent pump 4 is preferably a double plunger type pump so as to cope with a reduction in pulsating flow and an increase in discharge pressure. In particular, the material of the wetted part is a chemical resistance that does not react with the reaction reagent 3. Is desirable.

  If the reaction reagent 3 needs to be mixed immediately before measurement due to storage problems, it can be pumped with a pump with a low-pressure gradient function that is mixed on the suction side of the reaction reagent pump 4 The liquid can be fed in a state where a plurality of reagents are mixed.

  The thermostat 10 has a mixing coil 11 made of a thin tube, and promotes the reaction between the reaction reagent 3 and the sample (5a, 5b, 5c, 5d) by the mixing effect and heating due to diffusion and flow in the mixing coil 11. . As the set temperature in the thermostat 10, the temperature at which the reaction is completed is obtained experimentally.

  The detector 12 detects a peak due to the reaction between the sample and the reaction reagent 3. Generally, a flow cell type ultraviolet / visible spectrophotometer is used. The peak from the detector 12 is output as an intensity change of the electric signal according to the magnitude of the peak.

  The data processing unit 13 performs a quantitative calculation based on the change amount of the electric signal intensity from the detector 12. Since the signal from the detector 12 of this embodiment is output in the form of a chromatogram, a data processing device for chromatograph can be used as it is as the data processing unit 13 to be used.

  The control unit 14 controls the pumps 2 and 4 and the sample introduction units A, B, C, and D, the thermostatic chamber 10, the detector 12, and the data processing unit 13, and inputs parameters necessary for controlling the entire system. It can be performed. In FIG. 1, for the sake of easy understanding of the control target controlled by the control unit 14, a broken line is attached for convenience.

(Description of operation)
The operation of this apparatus will be described with reference to FIG.

  The carrier liquid pump 2 feeds the carrier liquid 1 and flows into the introduction switching valve 8a in the sample introduction unit A.

  The introduction switching valve 8a becomes a solid line in the initial state and sampling, and when the sample 5a or the standard solution 6a is introduced into the carrier liquid, the valve is switched to a broken line. The sample 5a to be supplied to the sample loop 80a and the standard solution 6a are switched by the selection switching valve 9a, and the selected one is supplied to the sample loop 80a by suction of the sampling pump 7a. These operations are performed under the control of the control unit 14.

  The operations of the sample introduction units B, C, and D are performed in the same manner as the sample introduction unit A, and each sample introduced into the carrier liquid merges with the reaction reagent 3, and the mixing coil (reaction in the thermostat 10). Coil) 11 mixes and reacts and is detected by detector 12.

  The operation of each introduction switching valve will be described with reference to the relationship diagram of measurement time by the general FIA method shown in FIG.

  FIG. 2 shows a peak detected by switching the introduction switching valve 8d of the sample 5d. The time T1 is the time until the sample 5d passes through the mixing coil 11, and this time T1 can be calculated by dividing the total flow rate of the carrier liquid 1 and the reaction reagent 3 with respect to the capacity of the mixing coil 11. . Time T2 is the time for the sample 5d to flow out of the sample loop 80d. The time T2 can be calculated by dividing the flow rate of the carrier liquid 1 with respect to the capacity of the sample loop 80d.

  In this apparatus, since a plurality of sample introduction valves are arranged in series in the flow path of the carrier liquid 1, detection is performed if the next sample is introduced after time T2 (that is, if the introduction of samples is performed sequentially and sequentially). Measurement can be performed without overlapping peaks with the instrument 12. The relationship between the time when four samples are introduced will be described with reference to the relationship between the measurement time and the valve operation according to the present embodiment shown in FIG.

  FIG. 3A is a schematic diagram virtually showing the relationship between time and sample introduction when this apparatus is used. In the figure, TS is the time for each sample introduction unit A, B, C, D to suck the samples 5a, 5b, 5c, 5d simultaneously. T25d is the time for the sample introduction unit D to introduce the sample 5d into the carrier liquid 1. Similarly, T25c, T25b, and T25a are times when the sample introduction units C, B, and A introduce the samples 5c, 5b, and 5a into the carrier liquid 1.

  FIG. 3B is a time chart (figure) showing the relationship between the operation of the introduction switching valve and time. For example, 8d in FIG. 3B indicates the operation of the introduction switching valve 8d, and among these, “L (Load)” indicates the initial state and the direction of the valve during sample suction. "Injection" "indicates the direction of the valve when the sample is introduced into the carrier liquid, and the same applies to the other introduction switching valves 8a, 8b, and 8c.

  In these operations, for example, the sample 5d is supplied to the introduction switching valve 8d during the sampling time TS, and after the time TS has elapsed, the direction of the introduction switching valve 8d is switched to “I” and the sample 5d is transferred to the carrier liquid 1. When T25d, which is the introduction time of the sample 5d, has elapsed, the direction of the introduction switching valve 8d is set to “L”. Next, the direction of the introduction switching valve 8d is changed to “L”, and simultaneously, the direction of the introduction switching valve 8c is changed from “L” to “I” to introduce the sample 5c into the carrier liquid 1, and time T25c. After the elapse of time, the direction of the introduction switching valve 8c is set to “L”, and at the same time, the direction of the introduction switching valve 8b is set to “I”. Thereafter, the direction of the valves is similarly switched for the introduction switching valves 8b and 8a.

  In the valve switching operation described above, the reason why the direction of the introduction switching valve 8d is changed from “I” to “L” at the time T25d has elapsed is that the introduction switching valve 8c to be introduced next is switched and the sample 5c to be introduced is The purpose of this is to prevent the unnecessary diffusion accompanying the decrease in sensitivity from occurring because the flow path becomes longer because it passes through the sample loop 80d of the introduction switching valve 8d. Therefore, in the operation of this apparatus, as shown in FIG. 3B, the direction of the valve is set to “I” only for the valves other than the introduction switching valve for introducing the sample, and the direction of the valve is set to “ L ".

  In the above valve switching operation, the introduction switching valve is switched from the downstream side of the carrier liquid 1 in the same manner, but the same result can be obtained even if it is performed in an arbitrary order.

  Moreover, in this apparatus, sample suction to each introduction switching valve can be performed simultaneously in time TS regardless of the number of samples. This shortens the measurement cycle time as compared with other methods in which sampling is performed for each specimen, and can contribute to a reduction in the consumption of the reaction reagent.

  FIG. 3C shows a peak state recorded in the data processing unit 13 by a solid line. FIG. 3C shows the relationship between each sample number shown in FIG. 1 and the passage time of the mixing coil 11. For example, the passage time T1 of the sample 5d through the mixing coil 11 is time T15d, and the time T2 until the sample 5d flows out of the sample loop 80d is time T25d. Furthermore, by continuously introducing the sample into the carrier liquid as shown in FIG. 3 (B) above, the peaks can be continued as shown in FIG. 3 (C). For example, when 4 samples are measured, The time T1 for three samples can be shortened, and the reaction reagent can be saved by stopping the reaction reagent pump 4 upon completion of the measurement.

  In this way, the explanation for the reason that the time T1 for three samples can be saved will be supplemented. The reason for this is that, as shown in FIGS. 3 (A) and 3 (B), the samples are introduced sequentially (that is, the valve direction of each introduction switching valve is sequentially switched to “L”). This is because the times T15d, T15c, T15b, and T15a overlap as shown in FIG. By superimposing T15d, T15c, T15b, and T15a in this way, as shown in FIG. 3C, a continuous structure in which peak overlap is prevented can be achieved.

  In addition, according to the present embodiment, a plurality of samples can be measured with a single flow injection analyzer, and it is not necessary to prepare a flow injection analyzer for each sample, thereby reducing costs. it can.

  In this embodiment, the sample introduction timing is performed with a time difference. However, even if each sample introduction valve is switched at the same time by connecting thin tubes having a capacity corresponding to the time difference between the sample introduction valves, Overlap can be prevented. However, in this case, as shown in the example in which the time difference operation of the valve in FIG. 4 is not performed, the flow path of the sample flowing out later becomes longer and the influence of diffusion increases, so the sensitivity gradually decreases, The analysis time is longer because the range is wider. From this, it can be understood that the switching of the introduction switching valve is more effective in ensuring sensitivity and shortening the measurement time if it is controlled by the time difference. Further, the fact that the carrier liquid piping between the sample introduction units can be connected in the shortest time is to minimize the influence of this diffusion.

(Other embodiments)
As another embodiment, an example applied to a process having a plurality of measurement items will be described with reference to FIG. A process that requires water quality monitoring generally requires a plurality of measurement items. The flow injection analyzer shown in FIG. 5 is provided with a selection switching valve 9 on the upstream side of the reaction reagent pump 4, and the selection switching valve 9 can be used by changing a plurality of reaction reagents. Other configurations are the same as those of the flow injection analyzer shown in FIG.

  The measurement item can be changed by changing the conditions of the reaction reagents 3 and 3 ′, the detector 12, and the data processing unit 13 flowing into the reaction reagent pump 4. The reaction reagents 3 and 3 ′ can be changed by connecting a selection switching valve 9 such as a one-flow path six-way valve on the suction side of the reaction reagent pump 4. Since this method requires time for replacing the reaction reagents 3 and 3 'by the reaction reagent pump 4, it is not suitable for a process that requires a short measurement cycle. This makes it possible to measure a plurality of items and a plurality of samples, thereby contributing to a reduction in facility introduction costs.

  The purpose of the present invention is to measure a plurality of samples by the conventional method, while the total time of sample replacement and measurement time is the sum of the number of samples resulting in an increase in measurement cycle time. An object of the present invention is to provide a flow injection analyzer capable of shortening a measurement cycle by simultaneously measuring a sample.

  Another object of the present invention is that the conventional method requires a number of devices corresponding to the number of samples, which causes problems in terms of device introduction cost and device maintenance cost. It is an object of the present invention to provide a flow injection analyzer that is easy to manufacture and can reduce manufacturing costs.

  Furthermore, another object of the present invention is that a conventional FIA is advantageous in terms of ensuring sensitivity and maintaining accuracy, while the conventional method has problems of long measurement time, stability of sensitivity and accuracy, and reagent consumption. An object of the present invention is to provide a flow injection analyzer that reduces the amount of reaction reagent consumed by shortening the measurement time.

  The flow injection analyzer according to the present embodiment is provided with an introduction switching valve corresponding to the number of samples for a carrier liquid pump, a reaction liquid pump, a thermostatic bath, a detector, and data processing by a general FIA method. It can be said that a control unit for controlling the entire system is provided by connecting the selection switching valve and the sampling pump to each introduction switching valve.

  The flow injection analyzer of the present embodiment is a sample introduction unit having a shape that can minimize the distance between each introduction switching valve, the configuration of the sample introduction switching valve, the sample and standard solution selection switching valve, and the sampling pump. It can be said that the sample introduction units corresponding to the number of samples are arranged and the pipes are connected in series with respect to the flow of the carrier liquid.

  The flow injection analyzer according to the present embodiment shortens the measurement time by switching the sample introduction by the introduction switching valve to the control unit of the flow injection analyzer according to claim 1 with a time difference, and sends the carrier liquid and the reaction liquid pump. It can be said that a program capable of operating only when measuring the liquid is provided.

  The flow injection analyzer according to the present invention has a plurality of sample introduction units arranged in series in a carrier liquid flow path, and measures a plurality of samples simultaneously in a short time by switching the valves according to the time difference of the introduction changeover valves. It can be said that.

  According to the present invention, when measuring a plurality of samples by the conventional method, the total time of the sample replacement time and the measurement time is an integration of the number of samples, which causes an increase in the time of the measurement cycle. It is possible to provide a flow injection analyzer capable of shortening a measurement cycle by measuring a sample at the same time.

  In the present invention, for a carrier liquid pump, a reaction liquid pump, a thermostatic bath, a detector, and data processing by a general FIA system, an introduction switching valve corresponding to the number of samples is connected in series to the carrier liquid flow path, A flow path selection valve and a sampling pump are connected to each introduction switching valve, and a control unit for controlling them is provided.

  The flow injection analyzer of the present invention can be used for water quality inspections such as water purification plants.

1 is a schematic configuration diagram showing a flow injection analyzer according to an embodiment of the present invention. It is a figure which shows the relationship (peak) of the measurement time by general FIA method, and signal strength. (A) is a schematic diagram virtually showing a relationship between time and sample introduction when the flow injection analyzer of the embodiment of the present invention is used, and (B) shows an introduction switching valve, introduction time, and (C) is a diagram showing a relationship (peak) between time and signal intensity when operated as in (A) and (B). It is a figure which shows the peak in case this embodiment does not utilize the time difference of a valve. It is a schematic block diagram which shows the flow injection analyzer of another embodiment of this invention.

Explanation of symbols

A, B, C, D Sample introduction unit (unit)
DESCRIPTION OF SYMBOLS 1 Carrier liquid 2 Carrier liquid pump 3 Reaction reagent 4 Reaction reagent pump 5a, 5b, 5c, 5d Sample 6a, 6b, 6c, 6d Standard solution 7a, 7b, 7c, 7d Sampling pump (pump)
8a, 8b, 8c, 8d Introduction switching valve 9a, 9b, 9c, 9d Selection switching valve 10 Constant temperature bath 11 Mixing coil 12 Detector 13 Data processing unit 14 Control unit 80a, 80b, 80c, 80d Sample loop

Claims (7)

A flow path through which the carrier liquid flows, and an introduction switching valve that introduces the sample supplied to the sample loop into the carrier liquid, and reacts the sample introduced into the carrier liquid with the reaction reagent, and results of the reaction In a flow injection analyzer for measuring
A plurality of the introduction switching valves are arranged in series on a flow path through which the carrier liquid flows. In the flow injection analyzer according to claim 1,
Each of the introduction switching valves simultaneously performs suction of a sample assigned to each introduction switching valve. In the flow injection analyzer according to claim 2,
Each of the introduction switching valves introduces a sample sequentially and sequentially into the carrier liquid, and is a flow injection analyzer. In the flow injection analyzer according to claim 3,
A flow injection analyzer characterized by introducing a sample into a carrier liquid in order from a downstream introduction switching valve. In the flow injection analyzer according to claim 3,
A flow injection analyzer characterized by stopping the introduction of a sample into another introduction switching valve while the sample is being introduced into one of the introduction switching valves. In the flow injection analyzer according to claim 1,
The flow injection analyzer according to claim 1, wherein the volume of the sample loop of each introduction switching valve can be changed according to the concentration of the supplied sample. In the flow injection analyzer according to claim 1,
A flow injection analyzer comprising a plurality of units, wherein an introduction switching valve, a selection switching valve for selecting a sample and a standard solution, and a pump for sucking the sample and the standard solution into a sample loop are provided as one unit. .

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