JPS621213B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid analysis method in which a sample liquid is quantitatively sampled from a sample liquid sampling port using a liquid metering pump and is sent to a liquid analyzer for analysis.

When it is desired to make the sample liquid acidic for measurement, a conventional method is to add an acid solution as a sample preparation liquid to the entire sample liquid near the sample liquid collection port. For this reason, a large amount of a highly concentrated acid solution must be added, resulting in corrosion and deterioration of the sample conduit, drainage channel, etc., and the PH adjustment setting value fluctuates due to changes in flow rate. In addition, since the acid solution is added before the sample solution is quantified, the sample solution cannot be quantified accurately, resulting in measurement errors, and most of the added acid solution is wasted. It was hot.

The present invention solves the above-mentioned drawbacks by devising the injection position of the liquid for sample preparation, and
The purpose is to use the calibration period when no analytical operation is being performed to clean the sample liquid collection port, where gel-like substances and the like tend to adhere, and to practice good analysis through these steps.

Next, embodiments of the present invention will be described based on the drawings. FIG. 1 shows one embodiment of the present invention, in which reference numeral 1 denotes a sample liquid collection port, which is equipped with, for example, a filter. 2 is a liquid metering pump, 3 is a liquid analyzer such as an oil content meter, and 4 is a liquid metering pump for sample preparation.
A liquid injection pump for adjustment injects the sample liquid into the sample liquid before being fed to the liquid analyzer 3 after passing through the liquid analyzer 3, and a cleaning liquid injection pump 5 that injects the cleaning liquid into the sample liquid conduit 6 between the metering pump 2 and the sample liquid collection port 1. It's Ponbu. A solenoid valve 7 is inserted between the pump 5 and the conduit 6 and is opened only during calibration.

When an oil meter using a solvent extraction method is used as the liquid analyzer 3, adjusting the pH of the sample liquid to 4 or less is extremely effective in improving oil extraction efficiency. Therefore, in this embodiment, dilute hydrochloric acid or a solution containing several salts is used as the sample preparation liquid. The pump 4 for injecting this liquid is operated continuously or intermittently depending on the characteristics of the liquid analyzer. However, it is configured to stop during calibration. On the other hand, the cleaning liquid is also used as a zero calibration liquid adjusted to PH4 or less, and when calibrating by opening the solenoid valve 7, this cleaning liquid is flowed into both the sample liquid sampling port 1 and the oil content meter 3, and the cleaning liquid is used to clean the sampling port 1 and remove oil. A total of three zero point calibrations can be performed simultaneously with the same liquid. For this reason, the metering pump 2 is operated even during calibration, and the flow rate q5 of the cleaning liquid injection pump 5 is made larger than the flow rate q2 of the metering pump 2, so that the zero calibration liquid is also required for cleaning in one direction of the sampling port. It is supplied at a suitable pressure or flow rate.

Therefore, according to this configuration, during analysis, the sample liquid that has passed through the metering pump 2 is injected with a liquid for sample adjustment, the pH of which is adjusted to 4 or less, and then sent to the oil meter 3. In this case, the sample adjustment liquid is injected into the sample liquid that has passed through the metering pump 2, so the pH can be adjusted without changing the absolute amount of oil contained in the sample liquid, thus achieving high accuracy. analysis becomes possible.

On the other hand, during calibration, the cleaning liquid injection pump 5 operates to supply zero calibration liquid that also serves as a cleaning liquid to both the oil content meter 3 and the sample liquid sampling port 1. At the same time, gel-like substances and suspended substances adhering to the filter vessel, etc., are removed. By cleaning the sampling port 1 during calibration in this manner, good analysis operation without clogging of the over-mechanical device is ensured during analysis after calibration.

Next, other embodiments of the present invention are shown in FIGS. 2 to 5, respectively. In the embodiment shown in FIG. 2, pressurized air is intermittently pumped together with a cleaning liquid to the sample liquid collection port 1 during calibration to enhance the cleaning effect, and 8 in the figure is an air pump. Figure 3A
In the embodiment shown in FIG. 1, a liquid exclusively for cleaning is used in addition to the zero calibration liquid, and is supplied to the sampling port 1 through a solenoid valve 7 by a pump 5.
In the figure, 9 indicates 3, which switches the flow path between analysis and calibration.
The sample liquid conduit 6 connected to the electromagnetic valve 9 has a bulge 6a as shown in FIG.
0' is inserted so that the cleaning liquid can be injected. The reason for this configuration is that the sample liquid inlet side of the three-way solenoid valve 9 is also cleaned by the cleaning liquid. In this example, the flow rate _qz of the zero calibration liquid or span calibration liquid is determined by the metering pump 2.
is the same as the flow rate q2.

The embodiment shown in FIG. 4 has two sample liquid sampling ports 1, 1, which are used alternately by switching the solenoid valve 10, and pressurized air is supplied to the sampling port 1 that is not in use. It is designed to clean by pumping water. Therefore, the sampling ports 1, 1 are cleaned not only during calibration but also when not in use, which is extremely effective when continuously measuring sample liquids containing a large amount of suspended solids. In addition, 11 in the figure is a solenoid valve for pressurized air switching.

In addition to the embodiment shown in FIG. 4, the embodiment shown in FIG. This is designed to further enhance the cleaning effect of the sampling port 1 due to the presence of dust. In the figure, 12 is a water tank for storing the sample liquid after passing through the analyzer 3, and 13 is a water tank for collecting the sample liquid in the water tank 12. The pump 14 that supplies to the port 1 side is a supply path switching solenoid valve.

As explained above, the present invention provides a liquid analysis method in which a sample liquid quantitatively collected by a liquid metering pump from a sample liquid sampling port is sent to a liquid analyzer for analysis.
During analysis, a sample conditioning liquid is injected into the sample liquid after passing through the liquid metering pump and before being fed to the liquid analyzer, while during calibration, a cleaning liquid is injected between the metering pump and the sample liquid inlet. Since it is designed to clean the sample liquid sampling port, it has the following advantages.

During analysis, the liquid for sample adjustment is injected into the sample liquid after passing through the liquid metering pump, so the liquid is used effectively and does not affect the quantitative determination of the sample liquid. As long as the amount of liquid injected is maintained at an appropriate level, adjustment settings such as pH remain constant, and highly accurate analysis becomes possible.

During calibration when no analysis is being performed, the cleaning liquid is added to the sample liquid sampling port in the opposite direction to the flow direction of the sample liquid, so that gel-like substances, suspended substances, etc. adhering to the sampling port are removed. Therefore,
At the time of analysis, good analysis operation is achieved by combining the advantages mentioned above.

Note that the cleaning technique disclosed in the present invention can also be employed, for example, in a chemical oxygen demand COD measuring device. FIG. 6 shows its configuration, in which 61 is a sample liquid collection port, 62 is a sample liquid conduit, and 63
64 is a cleaning liquid injection pump, 64 is a measuring section, 65 is a pump for evacuation to introduce a sample liquid into the measuring section 64, 66 and 67 are electromagnetic valves, and 68 is an analysis section.
In this configuration, the amount of cleaning liquid injected by the pump 63 is greater than the amount of sample liquid introduced by the pump 65. Therefore, both the measuring section 64 and the sample liquid sampling port 61 can be cleaned with the cleaning liquid.

[Brief explanation of the drawing]

FIG. 1 is a piping configuration diagram showing one embodiment of the liquid analysis method according to the present invention, and FIGS. 2 to 5 are piping configuration diagrams showing other embodiments of the present invention. FIG. 6 is a diagram showing the configuration for cleaning the COD measuring device. 1...Sample liquid collection port, 2...Liquid metering pump,
3...Liquid analyzer.

Claims (1)

[Claims] 1 In a liquid analysis method in which a sample liquid is quantitatively sampled by a liquid metering pump from a sample liquid sampling port and is sent to a liquid analyzer for analysis, during analysis, the sample is collected after passing through the liquid metering pump and before being sent to the liquid analyzer. Liquid analysis characterized in that, while a liquid for sample preparation is injected into the liquid, during calibration, a cleaning liquid is injected between the metering pump and the sample liquid sampling port to clean the sample liquid sampling port. Method.