JPH0479417B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a combustion type water quality analyzer in a total carbon meter (TC) or total nitrogen meter (TN) that intermittently introduces a sample solution, and is capable of detecting an abnormality in the analysis system. This is an attempt to increase the accuracy of analysis.

In total carbon and total nitrogen meters, the time from sample solution injection to peak measurement is constant in a normal analytical system. However, if an abnormality occurs in the analyzer, such as clogging of the combustion catalyst, dust clogging of the filter, or leakage, the carrier gas flow rate becomes abnormal and true measurement data cannot be obtained.

This invention was made in view of these circumstances, and its specific configuration includes a combustion section for vaporizing a sample solution, a sample injection section connected to one end of the combustion section, and a pipe at the other end of the combustion section. In a combustion-type water quality analyzer that is equipped with a moisture condensing section and a detection section that are connected in sequence by a Detecting that the sample solution has been introduced into the combustion section based on changes in the temperature, pressure, or humidity of the gas, measuring the time from the detection of the introduction of the sample solution to the detection of the target component by the detection section, and measuring the time. This is a combustion type water quality analyzer equipped with a monitoring means that monitors the analyzer by comparing the time with normal values.

In other words, the present invention uses a specific monitoring means for monitoring the analysis system to measure the time from the detection of introduction of the sample solution to the detection of the target component by the detection unit, thereby determining abnormalities in the analysis system and determining whether the analysis system is normal or not. It allows analysis to be carried out.

Specifically, the monitoring means in this invention measures the time from the detection of the introduction of the sample solution by a detector installed in the flow path to the detection of the target component by the detection unit, and compares the measured value with a normal value. An abnormality in the analysis system is determined by whether the value becomes larger or smaller than the normal value.

As a detector for detecting the introduction of a sample solution, for example, in the case of temperature detection, a detector with high sensitivity and quick response is preferable, and preferred examples include a thermocouple, a platinum resistor, and a thermistor.

The present invention will be explained in detail below with reference to embodiments shown in the figures. Note that this invention is not limited to this.

First, in FIG. 1, a total organic carbon meter (TOC) 1 as a combustion type water quality analyzer has a combustion section 2 consisting of a combustion tube 3 and an electric furnace 4 circumscribing the combustion tube 3. The inlet of the combustion tube 3 is equipped with a sample injection part 5 and a microsyringe 6 to be inserted into the sample injection part 5. On the other hand, from the outlet of the combustion tube 3, a temperature detector 7, a moisture condenser 8, and a filter 9 are installed. and the CO ₂ detector 10, and the CO ₂ detector 1
0 and a display/recorder 22 to which a temperature detector 7 is connected. Note that 11 is a combustion catalyst, 12 is a carrier gas supply path, 13 is a sample solution, and 14 is a pipe line.

FIG. 2 shows a temperature detector (or temperature sensor) 7 as a detection means, and a C.A.
A thermocouple 15, two compensation conductors 16 connected to this C/A thermocouple 15, and these conductors 16 connected to a conduit 14.
This is a temperature sensor composed of a sealing material 17 that seals the temperature sensor.

As shown in FIG. 1, the analyzer 1 configured as described above includes a combustion tube 3 heated by an electric furnace 4.
The sample solution 13 is injected by pressing one end of the microsyringe (for example, about 900° C.). The injected sample solution 13 immediately vaporizes in the combustion tube 3 and becomes high-temperature steam (eg, 800 to 900° C.), which is directed to the moisture condensing section 8 by the carrier gas flow constantly supplied from the carrier gas supply path 12. When the high-temperature water vapor exits the combustion tube 3 and reaches the temperature sensor 7 before the moisture condensing section 8, this water vapor is found to be at a significantly higher temperature (e.g., 30-40°C) than the carrier gas flow (e.g., 30-40°C).
(150℃), the arrival of this water vapor can be detected quickly and easily. Further, when this water vapor passes, the carrier gas flows and the temperature returns to the temperature when the carrier gas is flowing, in preparation for the introduction of the next sample solution 13.

FIG. 4 shows the relationship between the timing of the sample solution injector automatically recorded on the display/recorder 22, the notification signal (temperature) 20 of the introduction of the sample solution 13, and the measurement peak 21.

The time t 1 from the injection of the sample solution 13 to the notification signal ₂₀ and the time t ₂ to the measurement peak are such that t ₁ is constant due to the detection means of the present invention and t ₂ is constant due to the carrier gas flow. Since it is always constant, t ₂ −t ₁ is also always constant under normal measurement conditions.

By configuring this analyzer 1 in this way, the time from when the notification signal 20 is detected to when the measurement component is detected in the detection unit 10 is
By measuring t ₂ −t ₁ and comparing this time with a normal time, it is possible to determine whether the combustion catalyst 11 is clogged, the filter 9 is clogged with dust, or the carrier gas is leaking.
Furthermore, if the carrier gas flow rate fluctuates due to causes such as cracks occurring in the combustion tube 3, t ₂ -
t ₁ increases, and as a result, it is also possible to determine an abnormality in the carrier gas flow rate. Thus, it can be suitably used for automatic analysis such as a total organic carbon meter.

In addition, FIG. 3 shows another example of the detection means 2, and 7
a is a platinum resistance wire 18 wrapped around the outer periphery of the pipe 14a
This is a temperature sensor composed of a heat insulating material 19a covering the outer surface of the resistance wire.

Furthermore, in the analyzer 1, by using a pressure detector instead of a temperature detector, introduction of a sample solution can be detected in almost the same way.

This is because the pressure rises as the injected sample solution evaporates (eg 0.01Kg/cm ² :10cm water column).

Of course, a rise in temperature (or moisture concentration) also occurs, so it is also possible to employ a humidity detector.

In the field of chromatographic analysis, for example, an indirect detection method that electrically detects that a microsyringe, which is one of the sample solution injectors, is inserted into the sample solution injection part, is used. Even in the case of blank injection, where the sample solution is injected due to a work error without the sample solution being injected, carbon or nitrogen in the injected air will be detected, which may be confused with the detection results for the sample solution. In the case of a sample solution with a content close to that of air, there was a problem in that true measurement data could not be obtained.

In addition, since the microsyringe is injected by pressing one end with a human hand like a syringe, the timing at which the microsyringe actually starts injecting the sample solution after inserting it into the sample solution injection port varies depending on the operator, and It is no longer possible to accurately capture the time from solution injection to the detection peak of the sample solution, and therefore, although this time is normally kept constant by the action of a constant flow of carrier gas flowing through the analyzer, the flow path It becomes impossible to accurately detect changes in carrier gas flow rate due to clogging, leakage, etc.

[Brief explanation of the drawing]

Fig. 1 is a functional explanatory diagram of a total organic carbon meter using a temperature sensor as a detection means of a combustion type water quality analyzer according to the present invention, Fig. 2 is a sectional view illustrating the installation of the temperature sensor, and Fig. 3 2 is a diagram corresponding to FIG. 2 showing another example, and FIG. 4 is an explanatory diagram showing the relationship between the notification signal of sample solution introduction and the measurement peak. 1... Combustion type water quality analyzer, 2... Combustion part, 5...
...Sample solution injection part, 7...Temperature detector, 8...Moisture condensation part, 13...Sample solution.

Claims (1)

[Claims] 1. A combustion section that vaporizes a sample solution, a sample injection section connected to one end of the combustion section, a moisture condensation section connected in order to the other end of the combustion section by a pipe, and In a combustion type water quality analyzer that is equipped with a detection section and intermittently introduces a sample solution, a flow path between the combustion section and the moisture condensation section is provided with a sensor that responds to changes in the temperature, pressure, or humidity of the gas in the flow path. By detecting that the sample solution has been introduced into the combustion section based on the detection unit, measuring the time from the detection of the introduction of the sample solution to the detection of the target component by the detection unit, and comparing the measured time with the normal value. A combustion type water quality analyzer equipped with a monitoring means to monitor the analysis system.