JP4099379B2 - Droplet weighing and collecting device - Google Patents

Description

【００２５】
表１より、本発明によれば、液滴の滴下条件によって変化する液滴の液量を、実際の送液量に基づいて正確に決定できることがわかる。この場合、滴下時間間隔が安定しているときの液滴とは、その液滴が滴下するまでの滴下時間間隔が滴下時間間隔の平均値に近い液滴をいう。
【００２６】
また、特定の液滴の液量を演算により補正した例を次に示す。すなわち、表１において、その特定の液滴が滴下するまでの滴下時間間隔が長い場合は液滴の液量が大きく、その特定の液滴が滴下するまでの滴下時間間隔が短い場合は液滴の液量が小さいとみなし、時間配分による比例演算の考え方により、下記式を用いて滴下番号Ｎ＋ｎの液滴の液量を演算補正した。
滴下番号Ｎ＋ｎの液滴の液量＝液滴の液量の平均値×
｛（滴下番号Ｎ＋ｎの液滴の滴下時間間隔）／滴下時間間隔の平均値）｝
【００２７】
例えば、撥水性素材Ｂからなるノズルを用いた場合における滴下番号Ｎ＋７の液滴の液量の補正演算は、滴下番号Ｎ＋６とＮ＋７の間の滴下時間間隔が５．５３秒であるから、下記のようになる。
滴下番号Ｎ＋７の液滴の液量
＝９．２１１μＬ×（５．５３秒／５．５２７秒）＝９．２１６μＬ
【００２８】
【発明の効果】
以上のように、本発明の液滴計量採集装置によれば、液滴の滴下条件によって変化する液滴の液量を実際の送液量に基づいて正確に決定することができるとともに、液量が安定した液滴のみを採集することができる。
【図面の簡単な説明】
【図１】本発明に係る液滴計量採集装置の一例を示す概略図である。
【図２】従来の液滴計量採集装置の一例を示す概略図である。
【符号の説明】
１２ シリンジポンプ
１４ シリンジ
１６ ピストン
２０ パルスモータ
２２ 液滴下ノズル
２４ 採集管
２６ 採集シャッタ
２８ ソレノイド
３０ 試料液流通管
４８ 制御および演算ユニット
６０ 液滴センサ
６２ 発光部
６４ 受光部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a droplet measuring and collecting apparatus that collects a droplet by making a sample liquid drop into a small droplet from the tip of a nozzle. The droplet measuring and collecting apparatus according to the present invention is used, for example, in an analyzer for measuring a component in a gas obtained by dropping a droplet of a sample liquid into a combustion section and dropping and burning the droplet in the combustion section. The
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is known an analyzer that measures a component in a gas obtained by making a sample liquid into a minute droplet and dropping it into a combustion part, and burning the droplet while dropping in the combustion part. Examples of such analyzers include a combustion TOC meter and a combustion total nitrogen meter.
[0003]
In this case, as a droplet measuring and collecting apparatus for dropping a sample liquid into droplets, there is a conventional one shown in FIG. 2 (see, for example, Patent Document 1). In the liquid drop collection device of FIG. 2, 12 indicates a syringe pump. The syringe pump 12 includes a syringe 14, a piston 16, a temperature adjustment mechanism (for example, a heater) 18, and a pulse motor 20 that drives the piston 16 to reciprocate. In the figure, reference numeral 22 denotes a lower droplet nozzle connected to the syringe pump 12, 24 denotes a collection tube disposed below the lower droplet nozzle 22, 26 denotes a collection shutter for opening and closing the upper opening of the collection tube 24, and 28 denotes The solenoid which reciprocates the collection shutter 26 is shown.
[0004]
Further, in the figure, 30 is a sample liquid flow pipe, 32 is a filter provided in the sample liquid flow pipe 30, 34 is a pipe provided between the filter 32 installation portion of the sample liquid flow pipe 30 and the syringe pump 12, 36 Is a solenoid valve interposed in the pipe 34, 38 is a pipe between the syringe pump 12 and the droplet lowering nozzle 22, 40 is a solenoid valve interposed in the pipe 38, 42 is a cleaning liquid tank, and 44 is a cleaning liquid tank 42. A pipe provided between the syringe pump 12, 46 is an electromagnetic valve interposed in the pipe 44, and 48 is a control and arithmetic unit. The control and arithmetic unit 48 is electrically connected to and controls the temperature adjusting mechanism 18, the pulse motor 20, the solenoid 28, and the electromagnetic valves 36, 40, and 46 described above.
[0005]
The droplet measuring and collecting apparatus in FIG. 2 collects sample liquid droplets as follows.
(1) With the electromagnetic valve 36 open and 40 and 46 closed, the piston 16 is retracted by the operation of the pulse motor 20, and the sample liquid flowing through the sample liquid flow pipe 30 is introduced into the syringe 14 through the pipe 34. .
[0006]
(2) With the electromagnetic valve 40 open and 36 and 46 closed, the piston 16 is advanced by the operation of the pulse motor 20, and the sample liquid in the syringe 14 is sent to the liquid drop nozzle 22 through the pipe 38. A sample liquid droplet is dropped from the tip of the nozzle 22.
[0007]
(3) The operation of the solenoid 28 retracts the collection shutter 26 to open the upper opening of the collection tube 24, and the necessary droplet 50 out of the droplets dripped from the tip of the lower droplet nozzle 22 is contained in the collection tube 24. Let fall. This droplet is further dropped into the combustion section of the analyzer. Further, unnecessary droplets 525 are prevented from entering the collection tube 24 by advancing the collection shutter 26 by the operation of the solenoid 28 to close the upper opening of the collection tube 24.
[0008]
(4) If necessary, with the solenoid valve 46 open and 36, 40 closed, the piston 16 is retracted by the operation of the pulse motor 20, and the cleaning liquid in the cleaning liquid tank 42 is introduced into the syringe 14 through the pipe 44. After that, with the solenoid valve 40 opened and 36 and 46 closed, the piston 16 is advanced by the operation of the pulse motor 20, and the cleaning liquid in the syringe 14 is sent to the sub-droplet nozzle 22 through the pipe 38. The flow path is washed by discharging from the tip of 22.
[0009]
In the conventional droplet measuring and collecting apparatus shown in FIG. 2, the amount of droplet liquid (the amount of sample liquid per droplet) is determined by the advance amount of the piston 16. Specifically, the relationship between the number of feed pulses of the pulse motor 20 and the amount of liquid droplets generated and dropped from the tip of the lower droplet nozzle 22 by the sample liquid sent at the number of feed pulses is examined in advance. The liquid volume of the droplet is determined according to the relationship.
[0010]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-73467
[Problems to be solved by the invention]
In the conventional droplet measuring and collecting apparatus shown in FIG. 2, as described above, the liquid amount of the droplet is determined by the advance amount of the piston of the syringe pump. Therefore, the amount of liquid droplets is not actually measured. However, in practice, the droplet dropping conditions vary depending on the adhesion of dirt in the tip of the nozzle below the droplet, the degree of contamination of the sample liquid, the type of sample liquid, temperature change, the material of the nozzle below the droplet, etc. Even if the advance amount is the same, the liquid amount of the droplet may change.
[0012]
Nonetheless, the conventional liquid drop collection device does not actually measure the liquid volume of the liquid droplets, and assumes that the liquid volume of the liquid droplets is the same if the advance amount of the piston is the same. However, the actual liquid volume of the liquid droplets may differ from the liquid volume of the liquid droplets determined by the liquid droplet collection and collection device. In such a case, there is a problem that the sample liquid cannot be accurately analyzed. It was.
[0013]
An object of the present invention is to provide a droplet measuring and collecting apparatus that can accurately determine the liquid amount of a droplet and collect only a droplet with a stable liquid amount.
[0014]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention provides a sample liquid metering pump, a droplet lower nozzle connected to the metering pump, and for dropping droplets of the sample solution fed from the metering pump; A droplet collecting mechanism for collecting a desired droplet out of the droplets dropped from the nozzle below the droplet, and a droplet sensor for measuring the number of droplets dropped from the nozzle below the droplet and a dropping time interval In addition, of the droplets dropped from the nozzle below the droplet, the droplet when the dropping time interval is stable is collected by the droplet collecting mechanism, and is sent from the quantitative liquid feeding pump to the nozzle below the droplet within a predetermined time. An average value of the liquid volume of the liquid droplet is calculated from the amount of the sample liquid that has been liquidated and the number of liquid droplets dropped from the nozzle below the liquid droplet within the predetermined time, and the average value of the liquid volume of the liquid droplet is calculated as the liquid volume. Droplet measuring and collecting device characterized by the amount of liquid collected by the drop collecting mechanism To provide.
[0015]
The droplet weighing and collecting apparatus of the present invention measures the droplet dropping time interval by the droplet sensor and collects the droplet when the dropping time interval is stable by the droplet collecting mechanism, so that the liquid amount is stable. Only collected droplets can be collected. In addition, because the average value of the liquid volume of the liquid droplet is calculated from the amount of the sample liquid fed from the constant volume liquid feed pump to the nozzle below the liquid droplet within a predetermined time and the number of liquid droplets dropped from the nozzle below the liquid droplet, The liquid volume of the droplet can be calculated based on the actual liquid feed volume, so that the liquid volume of the droplet can be accurately determined.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic view showing an example of a droplet measuring and collecting apparatus according to the present invention. The droplet measuring and collecting apparatus of this example is obtained by adding a droplet sensor 60 to the conventional apparatus shown in FIG. 2, and the other points are the same as the apparatus shown in FIG. Parts having the same configuration are denoted by the same reference numerals, and description thereof is omitted.
[0017]
The droplet sensor 60 of the apparatus of this example is disposed below the lower droplet nozzle 22 and measures the number of droplets dropped from the lower droplet nozzle 22 and the dropping time interval. Specifically, the droplet sensor 60 is an optical sensor including a light emitting unit 62 and a light receiving unit 64, and drops of liquid droplets that fall from the droplet lower nozzle 22 and pass between the light emitting unit 62 and the light receiving unit 64. Measure the number and drop time interval. The droplet sensor 60 is electrically connected to the control and arithmetic unit 48.
[0018]
The droplet measuring and collecting apparatus of this example collects a sample liquid droplet as follows.
(1) With the electromagnetic valve 36 open and 40 and 46 closed, the piston 16 is retracted by the operation of the pulse motor 20, and the sample liquid flowing through the sample liquid flow pipe 30 is introduced into the syringe 14 through the pipe 34. .
[0019]
(2) With the electromagnetic valve 40 open and 36 and 46 closed, the piston 16 is advanced by the operation of the pulse motor 20, and the sample liquid in the syringe 14 is sent to the liquid drop nozzle 22 through the pipe 38. A sample liquid droplet is dropped from the tip of the nozzle 22.
[0020]
(3) The droplet dropping time interval is measured by the droplet sensor 60, and the collection shutter 26 is moved backward by the operation of the solenoid 28 to open the upper opening of the collection tube 24, and the droplet is dropped from the tip of the nozzle 22 below the droplet. Among the droplets, the droplet 66 when the dropping time interval is stable is dropped into the collection tube 24. This droplet is further dropped into the combustion section of the analyzer. In this case, the number of droplets dropped from the lower droplet nozzle 22 by the droplet sensor 60 is measured, and in the control and calculation unit 48, the sample sent from the syringe pump 12 to the lower droplet nozzle 22 within a predetermined time. An average value of the liquid amount of the liquid droplet is calculated from the amount of the liquid and the number of liquid droplets dropped from the sub-droplet nozzle 22 within the predetermined time, and the average value of the liquid amount of the liquid droplet is calculated in the collecting tube 24. The amount of liquid droplets dropped on the liquid. Further, the unnecessary droplet 68 prevents the liquid droplet 68 from entering the collection tube 24 by moving the collection shutter 26 forward by the operation of the solenoid 28 and closing the upper opening of the collection tube 24.
[0021]
(4) If necessary, with the solenoid valve 46 open and 36, 40 closed, the piston 16 is retracted by the operation of the pulse motor 20, and the cleaning liquid in the cleaning liquid tank 42 is introduced into the syringe 14 through the pipe 44. After that, with the solenoid valve 40 opened and 36 and 46 closed, the piston 16 is advanced by the operation of the pulse motor 20, and the cleaning liquid in the syringe 14 is sent to the sub-droplet nozzle 22 through the pipe 38. The flow path is washed by discharging from the tip of 22.
[0022]
In addition, the syringe pump 12 used in this example is an example of a quantitative liquid feeding pump, and an arbitrary configuration can be used as the quantitative liquid feeding pump. Further, in this example, the droplet collection mechanism is configured by the collection tube 24, the collection shutter 26, and the solenoid 28. However, the droplet collection mechanism may be configured arbitrarily. Furthermore, other structures may be used as the liquid drop nozzle and the liquid drop sensor.
[0023]
【Example】
Examples are shown below, but these examples do not limit the scope of the present invention. Droplets were generated and collected using the droplet weighing and collecting apparatus shown in FIG. In this case, the amount of the sample liquid fed from the syringe pump 12 to the lower droplet nozzle 22 was 100 μL / min. Further, as the liquid drop nozzle 22, a nozzle made of a hydrophilic material (cellulose), a nozzle made of a water repellent material A (PEEK: polyetheretherketone), and a nozzle made of a water repellent material B (PTFE: polytetrafluoroethylene) Three kinds of were used. As the sample liquid, two kinds of pure water and an impurity solution were used in the case of a nozzle made of a hydrophilic material, and only pure water was used in the case of a nozzle made of a water repellent material A or B. Table 1 shows the results obtained by measuring the drop time interval (seconds) of the droplets having the droplet numbers N to N + 10 by the droplet sensor 60 and the calculation result of the average value (μL / min) of the liquid volume of the droplets. Here, the average value of the liquid volume of the droplets was calculated by the following formula.
Average value of liquid volume of droplets =
(Liquid feed amount of sample liquid × total dropping time interval) / (number of droplets × 60)
Sample liquid feed rate: 100 μL / min Drop time interval total: Σ (NT) in Table 1
Number of droplets: 10 [0024]
[Table 1]

[0025]
From Table 1, it can be seen that according to the present invention, the amount of liquid droplets that varies depending on the droplet dropping conditions can be accurately determined based on the actual liquid supply amount. In this case, the droplet when the dropping time interval is stable refers to a droplet whose dropping time interval until the dropping of the droplet is close to the average value of the dropping time interval.
[0026]
An example in which the liquid amount of a specific droplet is corrected by calculation will be described below. That is, in Table 1, when the drop time interval until the specific droplet is dropped is long, the liquid volume of the droplet is large, and when the drop time interval until the specific droplet is dropped is short, the droplet is dropped. The liquid amount of the droplet of the droplet number N + n was calculated and corrected using the following formula based on the concept of proportional calculation based on time distribution.
Droplet number N + n droplet volume = average droplet volume ×
{(Drop time interval of the droplet of the drop number N + n) / Average value of the drop time interval)}
[0027]
For example, when the nozzle made of the water-repellent material B is used, the correction calculation of the liquid amount of the droplet with the droplet number N + 7 has a dropping time interval between the droplet numbers N + 6 and N + 7 of 5.53 seconds. It becomes like this.
Liquid volume of droplet No. N + 7 = 9.211 μL × (5.53 seconds / 5.527 seconds) = 9.216 μL
[0028]
【The invention's effect】
As described above, according to the droplet measuring and collecting apparatus of the present invention, it is possible to accurately determine the liquid amount of the droplet that changes depending on the droplet dropping condition based on the actual liquid feeding amount, However, only stable droplets can be collected.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a droplet measuring and collecting apparatus according to the present invention.
FIG. 2 is a schematic view showing an example of a conventional droplet measuring and collecting apparatus.
[Explanation of symbols]
12 Syringe pump 14 Syringe 16 Piston 20 Pulse motor 22 Droplet lower nozzle 24 Collection tube 26 Collection shutter 28 Solenoid 30 Sample solution flow tube 48 Control and arithmetic unit 60 Droplet sensor 62 Light emitting unit 64 Light receiving unit

Claims (4)

A sample liquid feed pump, a liquid drop nozzle connected to the liquid feed pump for dropping liquid droplets of the sample liquid sent from the liquid feed pump, and a liquid drop dropped from the liquid drop nozzle A droplet collecting mechanism that collects a desired droplet in the inside, and a droplet sensor that measures the number of droplets dropped from the nozzle below the droplet and a dropping time interval, and the droplet dropped from the nozzle below the droplet In addition, the droplets when the dropping time interval is stable are collected by the droplet collecting mechanism, and the amount of the sample liquid fed from the quantitative liquid feeding pump to the nozzle below the droplets within the predetermined time, and the predetermined amount The average value of the liquid volume of the liquid droplet is calculated from the number of liquid droplets dropped from the nozzle below the liquid droplet within the time, and the liquid volume of the liquid droplet collected by the liquid droplet collecting mechanism is calculated from the average value of the liquid volume of the liquid droplet A droplet weighing and collecting apparatus characterized by comprising: 2. The droplet measuring and collecting apparatus according to claim 1, wherein an average value of the liquid amount of the droplets is calculated by the following formula.
Average value of liquid volume of droplet (μL) =
(Liquid feed rate of sample liquid (μL / min) × drop time total) / (number of droplets × 60) The liquid amount of the specific droplet is corrected by calculation from the average value of the liquid amount of the droplet, the average value of the dropping time interval, and the dropping time interval until the specific droplet is dropped. The liquid drop collection device according to claim 1 or 2. 4. The droplet measuring and collecting apparatus according to claim 3, wherein the liquid amount of the specific droplet is corrected by calculation using the following equation.
Liquid volume of a specific droplet = average value of liquid volume of droplets x
{(Drop time interval until specific drop is dropped / Average value of drop time interval)}

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