JPS6013254A - Detection of contamination for flow through type analyzer - Google Patents

Abstract

PURPOSE:To enable the detection of the degree of contamination in a passage and of a sensor electrode accurately by a simple method by quantitatively measuring the degree of contamination according to differentiated value of a sensor output generated which two kinds of standard solutions are switched. CONSTITUTION:Prior to the analyzing work, an electrode cell 1 is made to communicate with a standard solution A with a low concentration by a changeover valve 14 and as a pump 2 is operated to pour the standard solution A into the electrode cell 1, an electrode 5 outputs a signal of a level L1 proportional to the concentration of the standard solution. Then, with the changeover valve 14 turned to the standard solution B high in the concentration, the potential difference output of the electrode 5 increases in a sharp slope when the degree of the contamination is low while in a gentle slope when it is high. The change in the potential difference output is differentiated with a differentiation circuit 6 and indicated on a display 8 while it is compared with the reference signal by a comparator circuit 10, which actuates an alarm 11 when it is lower than the reference signal. Thus, the degree of contamination can be detected accurately by a simple method.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a method for detecting contamination in a flow path of a flow-through type analyzer.

Conventional technology Analyzers using flow-through type electrodes immerse the sensor electrode in a cell that is connected to a sample suction pump at one end and a sampling nozzle at the other end via a pipe, and the sample sucked from the sampling nozzle is passed through the cell to waste liquid. During the process of transporting to the tank, the pH and ion concentration are continuously measured using sensor electrodes.

When performing analysis between ffllll using such an analyzer, samples may adhere to the inner surfaces of flow path components such as nozzles, pipes, electromagnetic tubes, and electrode tanks, and the surfaces of sensor electrodes, resulting in contamination and detection errors. This has the disadvantage of causing

Conventionally, in order to eliminate such inconveniences, a cleaning solution was flowed into the channel to wash away the dirt after continuous analysis for a certain period of time.

However, according to such a method, washing is performed even when the contamination is slight, so that the electrodes of the sensor 7 are exposed to a strongly acidic or strongly alkaline cleaning solution.

There was a problem of shortening its lifespan.

C1 Purpose of the Invention In view of the above-mentioned problems, an object of the present invention is to propose a contamination detection method that can accurately detect the degree of contamination in a flow path and a sensor electrode using a simple method. 6 2. Structure of the Invention: 1. The feature of the present invention is that the degree of contamination is quantitatively detected by the potential difference response of the sensor core during calibration with a standard solution performed prior to the start of analysis work. That's the point.

E. EXAMPLES The details of the present invention will now be explained based on examples.

FIG. 1 is a configuration diagram showing an example of a flow-through type analyzer to which the present invention is applied, and reference numeral 1 in the figure indicates that one end is connected to a waste liquid tank 3 via a sample suction pump 2, and the other end is connected to a sampling nozzle. It is constructed by immersing a sensor electrode 5 according to the object to be analyzed in an electrode tank communicating with the electrode tank 4. 6 is a differential circuit that detects the potential difference response speed of the electrode 5 during one calibration operation, and the output from this is inputted to the contamination indicator 8 via the differential output measurement circuit 7 to quantitatively display the degree of contamination, and at the same time A cleaning level setting signal from the reference signal generator 9 is input to a manually operated comparison circuit 10, and contamination progresses. In addition, the code 1 in the figure
2.13 are standard solutions Δ and B having two different concentrations, each communicating with the sampling nozzle via the switching valve 14.
Reference numeral 15 indicates an electromagnetic valve C for taking in air which forms an air layer for the work vJ.

The operation of the apparatus constructed in this way will be explained based on the waveform diagram shown in FIG.

Prior to analysis work, the electrode tank 1 is connected to the standard solution A with a low concentration by the switching valve 14, and when the pump 2 is activated and the standard solution A is injected into the electrode tank 1, the electrode 5 is proportional to the concentration of the standard ill. Outputs a signal at level Ll. When this reaches a steady value, the first point is calibrated. When this first point calibration is completed, open the electromagnetic JP15 for a short time to form an air layer in the pipe, and at the same time switch the switch go f14 to the standard solution B with a higher concentration. The concentration changes stepwise. As a result, the potential difference output of the electrode 5 is increased on the head side according to the degree of contamination in the flow path, that is, by a steep head image 1 when the degree of contamination is low, and by a gentle slope when the degree of contamination is high. This increasing change in the potential difference II force is differentiated by a differentiating circuit 6 and displayed on a display 8. At the same time, it is compared with a reference signal by a comparator circuit 10, and when it is lower than the reference signal, an alarm 11 is activated.
is activated to promote cleaning of the flow path of the analyzer.

[Example] Immediately after cleaning the sample pipe system with a cleaning solution, 4 mEq/u
of potassium! Inject 6 m as the first standard solution, then 6 m
When a potassium solution of Eq/m was injected as the second standard solution, the electrode output when switching between the two standard solutions rose almost vertically (Fig. 3). Next, after analyzing 100 heparin action samples using this analyzer, we alternately switched the two types of standard LFK mentioned above and examined the output from the electrode.The slope became a little gentler, and the differential output was 82% of the differential output immediately after cleaning (II
). Furthermore, after analyzing 100 of the above samples,
When we investigated the differential output when switching the standard solution, it was 63%.
(III). From this, it was possible to quantitatively measure the degree of contamination in the road system by being inversely proportional to the differential output.

In this example, the standard fi liquid was switched from a low concentration to a high concentration, but it is clear that the same effect can be obtained even if the standard fi liquid is switched from a high concentration to a low concentration.

As described above, according to the present invention, the degree of contamination is determined quantitatively by the differential value of the sensor output generated when switching between two types of standard solutions, so that the tube containing the electrode The tract system can be cleaned at an appropriate time, and a highly reliable analytical device can be realized by preventing shortening of electrode life and occurrence of analysis errors due to excessive cleaning.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an example of a device to which the method of the present invention is applied, FIG. 2 is a waveform diagram showing the operation of the same device, and FIG. 3 is a flow path system. FIG. 2 is an explanatory diagram showing the relationship between contamination and the output of the upper electrode potential difference. 1... Electrode tank 2... Pump 3... Waste liquid tank 4... Sampling nozzle 5.
...Sensor electrode 12.13...Standard liquid tank Applicant Shimadzu Corporation Agent J1゛Physician Kei Nishikawa Time Katsuhiko Kimura/Ko agon ■C $3 times

Claims (1)

[Claims] Standard solutions with different concentrations are alternately injected into a flow-through type analyzer, which consists of a sensor electrode immersed in an electrode tank in which a sample flow path is formed from one end to the other. (g) A method for detecting contamination of a flow-through type analyzer, in which the differential value of the output signal from the electrode generated when switching to a quasi-liquid is calculated, and the P1 degree of contamination of the analyzer is determined based on this value.