JP3395407B2 - Analysis equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] The present invention relates to the total amount of nitrate ion and nitrite ion contained in factory drainage, land water / sea water / river water / lake water, soil solution, soil extract, plant / biological fluid. And a method for measuring each concentration.

[0002]

2. Description of the Related Art In chemical analysis, a method for obtaining the concentration for each chemical species is generally used, but components having similar chemical properties may be collectively quantified. Conventionally, in the case of collectively quantifying components having similar chemical properties and in the case of separately quantifying chemical species, two types of analyzers are used, or manual pretreatment suitable for each analysis is performed. Once done, the concentration had to be measured using an analyzer.

A method for determining nitric acid and nitrite ion in water will be described below. For the determination of nitrate ion in water, reduction distillation-ionized phenol blue absorptiometry, reduction distillation-
Neutralization titration method, copper / cadmium column reduction-naphthylethylenediamine absorption spectrophotometry, brucine absorption spectrophotometry, ion chromatography (above, JIS K0102-1993) are used. Of these methods, the Brucine absorption method is
The absorbance of the reaction product is measured when it reacts directly with nitrate ions to develop color. Since this method uses concentrated sulfuric acid, there is a safety problem. The reductive distillation / ionized phenol blue absorptiometry is a method in which nitrate ion and nitrite ion are reduced to ammonia for distillation, the distilled ammonia is absorbed by sulfuric acid, a coloring reagent is added, and the concentration is measured by an absorptiometry method. Is. In addition, the copper / cadmium column reduction-naphthylethylenediamine absorption spectrophotometric method is a method in which nitrate ion is reduced to nitrite ion, a coloring reagent is added, and the concentration is measured by the spectrophotometric method.

Although this method is carried out manually, it is subjected to a copper-cadmium column reduction-naphthylethylenediamine absorption spectrophotometric method (Analytica) using a flow injection analysis method.
Chimica Acta, 110 (1979) 123-128) is an automated device. The automatic analysis method has the following problems.

(1) Since the nitrate ion is reduced to the nitrite ion and then the concentration is measured, when the sample solution is a mixture of the nitrate ion and the nitrite ion, it can be quantified only as the total amount, and the respective concentrations are unknown. Absent.

(2) In the flow injection analysis method, since the sample solution is added to the place where the carrier solution and the color-developing reagent are continuously flowed in advance, a large amount of waste liquid is generated, and the burden of waste liquid treatment is large. , Running costs.

Therefore, the nitrate ion and the nitrite ion can be pretreated by one apparatus, and the total concentration can be quantified.
It would be advantageous to have a device that could select both quantification for each chemical species.

[0008]

SUMMARY OF THE INVENTION In the above-mentioned prior art, the nitrate ion is reduced to nitrite ion, and the total amount of nitrate ion and nitrite ion together with the nitrite ion already present in the sample is calculated. Although it is possible to quantify the concentration, it is not possible to quantify each concentration. Therefore, when performing such an analysis, it is necessary to construct an apparatus that takes the following measures.

(1) The analysis operation is simplified by simplifying the automatic operation without manually performing the analysis.

(2) It is possible to quantify the concentrations of both nitrate ion and nitrite ion.

(3) The consumption of the carrier solution and the coloring reagent is reduced to reduce the analysis cost.

It is an object of the present invention to provide a nitrate ion analyzer which can automatically measure both nitrate ion and nitrite ion, and can save labor of analysis operation and reduce analysis cost.

[0013]

In order to achieve the above object, a reduction column is attached to a flow path between a sample suction / exhaust pump and a movable sample suction / exhaust nozzle, and sample water reciprocates the reduction column once or more times. Chemical reaction during
It was possible to discharge the mixture into the mixing container through the nozzle. When the sample water goes back and forth through the reduction column, the sample water undergoes a chemical reaction such as reduction, and the total amount of the components having similar chemical properties can be obtained together with the reductant already existing in the sample water. On the other hand, when the sample water is sucked by the sample suction pump and the movable nozzle for sample suction and discharged, and is discharged without contacting the reduction column, only the chemical species that react with the coloring reagent already present in the sample water are quantified. You can also do it.
Thus, it becomes possible to automatically measure both nitrate ion and nitrite ion using one nozzle.

[0014]

[Function] When a reduction column is attached to the flow path between the sample suction / exhaust pump and the movable sample suction / exhaust nozzle, and the sample water is brought into contact with the reduction column, the total concentration of components having similar chemical properties can be quantified. When the sample water is sucked and discharged without being brought into contact with the reducing column, only the chemical species that react with the color forming reagent already present in the sample water can be quantified. That is, in the flow injection analysis method, the reaction solution or the sample solution is added while the sample solution or the reaction solution is continuously flowing in advance, whereas in the present invention, the sample solution and the reaction solution are sucked and discharged. This is a method, and a plurality of analyzes can be performed by bringing the reduction column and the sample solution into contact with each other during the suction and discharge. By this,
The sample solution and reaction solution will be used only in an amount necessary for analysis.

Further, by providing a control means for controlling the suction amount / discharge amount / aspiration / discharge speed of the sample solution and the coloring reagent, the number of times the sample solution is reciprocated in the reduction column, and the detection conditions.
It becomes possible to build an automatic analyzer.

[0016]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram of one embodiment of the present invention. This analyzer is roughly divided into a detection unit A, a sample supply unit B, and a control unit C.

In FIG. 1, 1: detector, 2: flow cell, 3: needle washing port, 4: sample injection port,
5: needle, 6: sample solution container, 7: reaction solution container,
8: sample rack, 9: flow path switching valve, 10: three-way valve, 11: reduction column, 12: syringe, 13: washing liquid. The needle 5 can move up and down at the needle washing port 3, the sample injection port 4, the sample solution container 6, and the reaction liquid container 7, and can move up and down at those positions. The following operation program shows a case where the flow path of the flow path switching valve 9 is set to the reaction column 11 side and the sample solution is reduced by the reduction column 11. The program for the following operation is created by the control unit C.

(1) A sample solution, a standard solution, and a reaction solution are set on the sample rack 8, the analysis conditions stored in advance are called to correct the changed portions, and then the analysis start key is pressed.

(2) The flow path of the flow path switching valve 9 is set to the reduction column 11 side, the flow path of the three-way valve 10a is set to the needle 5 side, and the needle 5 is put into the sample solution in the sample solution container 6a, and a fixed amount is set. Suction.

(3) The aspirated sample solution is added to the reduction column 11
Pass through. At this time, the sample solution is reciprocated in the reduction column 11 once or more until it is sufficiently reduced by the reduction column 11.

(4) The needle 5 is put in the sample solution container 6b, and the reduced sample solution is discharged. (5) Move the needle 5 to the needle washing port 3 to wash the outside of the needle 5.

(6) The needle 5 is put into the reaction solution in the reaction solution container 7 and a certain amount is sucked. At this time, the reaction liquid is not put into the reduction column 11.

(7) The needle 5 is placed in the sample solution container 6b, the reaction solution is discharged, and reacted with the reduced sample solution.

(8) Needle 5 is replaced with needle washing port 3
To wash the outside of the needle 5.

(9) The needle 5 is put into the sample solution container 6b, and the reaction product is sucked.

(10) Connect the needle 5 into the sample injection port 4.

(11) The suctioned reaction product is discharged to the flow cell 2 of the detector 1.

(12) The signal intensity of the detector 1 when the reaction product passes through the flow cell 2 is read.

(13) The concentration is calculated and the analysis result is output.

(14) Clean the flow path of the three-way valve 10a with the cleaning liquid 1
Switching to the 3 side, the cleaning liquid is sucked into the syringe 12a.

[0031] (15) switches the flow path of the three-way valve 10a to the needle 5 side, discharging a portion of the cleaning liquid in the syringe 12a into the flow cell 2, the cleaning of the flow cell.

(16) Replace the needle 5 with the needle washing port 3
Then, the washing liquid in the syringe 12a is discharged to wash the inner and outer walls of the needle 5.

(17) The standard solution is analyzed by the operations of (1) to (16) to prepare a calibration curve in advance, and the concentration in the sample solution is determined from the calibration curve.

On the other hand, the flow path of the switching valve 9 is set to the side where the reduction column 11 is not attached, and the analysis is performed without bringing the sample solution into contact with the reduction column. The operation in this method is the same as in the case of using the reducing column except the operation shown in (3) among the series of operations shown in (1) to (16).

According to the present embodiment, the sample solution is reduced by the reduction column and the total amount of the components having similar chemical properties is quantified at once, and the concentration of the reductant already contained in the sample solution. The method for quantifying only the amount can be performed by using only one needle, and there is an effect that labor saving of the analysis and simplification of the analysis system can be performed.

(Example 2) An example in which nitrate ions and nitrite ions are analyzed using the analysis system of Example 1 will be shown.
Table 1 shows the analysis conditions at that time.

[0037]

[Table 1]

In the embodiment shown in FIG. 1, a sample solution container 6a was charged with a nitrate ion solution of known concentration, a reaction solution container 7a was treated with a sulfanilamide solution, and a reaction solution container 7b was treated with N 2.
Analysis was performed by adding a-(1-naphthyl) ethylenediamine solution. First, put the needle 5 into the sample solution container 6a,
Aspirate 3000 μl of sample solution. Next, the needle is pulled up, 1700 μl of air is sucked, and at the same time, the sample solution is reciprocated once or more in the reduction column 11, and then the needle 5
To the needle washing port 3 and the sample solution 1500μ
l, the needle 5 is put into the sample solution container 6b,
Dispense 1000 μl of sample solution. The needle 5 is moved to the needle washing port 3, the outside of the needle 5 is washed, the needle 5 is moved to the reaction solution container 7a, 100 μl of the sulfanilamide solution is sucked, the needle 5 is moved to the needle washing port 3, The outer side of 5 is washed, then the needle 5 is moved to the reaction solution container 7b to suck 100 μl of the N- (1-naphthyl) ethylenediamine solution, and the needle 5 is further moved to the sample solution container 6b, and each is discharged. . The reaction product in the sample solution container 6b was sucked by the needle 5, inserted into the sample injection port 4, and the reaction product was discharged to read the signal intensity of the analyzer.

FIG. 2 shows the relationship between the number of reciprocations of the sample solution in the reduction column 11 and the signal intensity. The signal strength was the same for three round trips and four round trips and was the maximum. Therefore, the number of round trips was set to three in order to shorten the analysis time.

FIG. 3 is a calibration curve showing the relationship between concentration and signal intensity when nitrate ions having different concentrations are analyzed. A good correlation was obtained between the concentration and the peak height, indicating that it can be sufficiently used for practical analysis.

(Third Embodiment) FIG. 4 shows that the switching valve 9 is not used in the system of FIG.
A small capacity suction / discharge pump 12c and two large capacity suction / discharge pumps 12d are provided on the path of the needle 5 and the reduction column 11. In this system, when the sample solution and the reaction solution are sucked and discharged by using the small-capacity suction / discharge pump 12c, when the sample solution shown in the operation (3) of Example 1 is reciprocated in the reduction column 11, the reduction reaction is performed. This is performed using the large-capacity suction / discharge pump 12d.

According to the present embodiment, there is an effect that the nitrate ion of Embodiment 2 can be reduced to nitrite ion and the concentration can be quantified without using the switching valve for switching the flow path.

[0043]

EFFECTS OF THE INVENTION According to the present invention, a method of reducing nitrate ions in a mixed solution of nitrate ions and nitrite ions in a sample solution to nitrite ions in a reducing column and then quantifying the nitrite ions, and a sample The method for quantifying only the nitrite ion in the solution can be measured by using one needle, which can save labor of analysis and simplify the analysis system. Further, since it is not necessary to continuously flow the carrier solution and the coloring reagent, running cost is reduced.

[Brief description of drawings]

FIG. 1 is a system diagram of a nitrate ion analyzer.

FIG. 2 is a characteristic diagram of the relationship between the number of round trips in the reduction column and the signal intensity.

FIG. 3 is a characteristic diagram of a calibration curve during nitrate ion analysis.

FIG. 4 is a systematic diagram of a nitrate ion analyzer in which two syringes are provided on the flow path of a reduction column.

[Explanation of symbols]

A ... Detection part, B ... Sample supply part, C ... Control part, 1 ... Detector, 2 ... Flow cell, 3 ... Needle washing port, 4 ... Sample injection port, 5 ... Needle, 6 ... Sample solution container, 7 ...
Reaction liquid container, 8 ... Sample rack, 9 ... Flow path switching valve, 10 ... Three-way valve, 11 ... Reduction column, 12 ... Syringe, 13 ... Washing liquid.

Front page continuation (72) Inventor Chiaki Maeya 882 Ichimo, Katsuta City, Ibaraki Prefecture Hitachi Ltd., Measuring Instruments Division, Hitachi, Ltd. (56) Reference JP-A-63-243870 (JP, A) (58) Survey Areas (Int.Cl. ⁷ , DB name) G01N 35/08 G01N 21/77 G01N 31/00

Claims (4)

(57) [Claims] 1. A a needle for sucking-discharging specimen solution and / or the reaction liquid, and the flow channel switching valve in communication with the needle, communicates with the flow path switching valve, and a sample solution reduction
The reducing column and the solution is discharged through the reducing column.
A first flow path provided with a first syringe for ejecting / sucking, is connected to the flow path switching valve, and discharges / sucks a solution.
An analyzer equipped with a second flow path having a second syringe for drawing, a sample injection port into which a sample to be measured is introduced, and a detector for measuring the solution introduced into the sample injection port. Therefore, the flow path switching valve uses the reduction column.
When analyzing, connect the needle and the first flow path
However, when performing an analysis that does not use the reducing column,
The analyzer is characterized in that it connects the idler and the second flow path . 2. The reducing capacitor according to claim 1, between the first syringe and the reducing column.
The flow path connecting the ram and the first syringe and the cleaning liquid
First for switching the flow path introduced into the first syringe
And a three-way valve between the second syringe and the flow path switching valve.
Flow path connecting the flow path switching valve and the second syringe
And cut off the flow path for introducing the cleaning liquid into the second syringe.
An analysis device having a second three-way valve for replacement . 3. The washing port for washing the outside of the needle according to claim 1 ,
A number of sample containers and reaction solution containers containing reaction solutions are stored.
A sample rack, and the needle is connected to the sample injection port and the washing port.
Move to each position of each container on the sample rack
An analyzer characterized by being capable . 4. A reduction column for reducing the sample solution, a flow path for introducing a washing liquid into the reduction column, a needle for communicating with the reduction column and sucking and discharging the sample solution and / or the reaction liquid, A sample injection port into which a sample to be measured is introduced, and an analyzer equipped with a detector for measuring a solution introduced into the injection port, wherein the solution sucked from the needle is reduced in the flow path. A first syringe having a capacity capable of moving to the column and a second syringe having a capacity not allowing the solution sucked from the needle to move to the reduction column are provided, and the sample solution is passed through the reduction column. After that, the analysis that is introduced into the injection port and the analysis that the sample solution is introduced into the injection port without passing through the reduction column are selectively performed. And to analyze the device.