Flow injection serially connected microelectrode electrochemical automatic method and device for simultaneous measurement of various electrolytes in blood sample

Abstract

The invention discloses a flow injection serially connected microelectrode electrochemical automatic method and device for simultaneous measurement of various electrolytes in a blood sample, and belongs to the field of clinical examination. A multifunctional valve is arranged in a 'sampling' position, carrier flow is converged with an acidity regulator under the power action of a pump, continuously flows through a mixing coil and an electrochemical flow-through detector, and generates base line electrode potential signals; a blood sample simultaneously enters a sampling quantification ring for automatic precision quantification; a valve is switched to the 'injection' position, a quantified 'blood sample plug' is injected into the carrier flow in a high repetition manner, is mixed with the acidity regulator and flows into the electrochemical flow-through detector, respective potential signals can be obtained, and blood sample results can be obtained through a computer. Meanwhile, the carrier flow follows the 'blood sample plug' to automatically and timely clean an electrode sensitive membrane surface and a system. The invention has the advantages of high automation degree, fast measuring speed, good repeatability and less consumption of samples, and eliminates the system plugging caused by blood samples and the cross contamination.

Description

Technical field [0001] The invention relates to a flow injection microelectrode series electrochemical automatic analysis method and a measuring device (FI-ME-ECA) for simultaneously measuring electrolyte, and belongs to the field of clinical electrolyte analysis. The invention is suitable for rapid, accurate and automatic determination of electrolyte concentration in human serum. Background technique [0002] Electrolytes play an important role in maintaining the acid-base balance of body fluids and maintaining osmotic pressure. When the human body undergoes pathological changes, such as diabetes, acidosis, kidney failure, severe vomiting, diarrhea, exudative pleurisy or peritonitis, etc., the electrolyte concentration will deviate from the normal range. Therefore, timely determination of the electrolytes in the patient's body fluid is of great significance for the treatment of diseases. [0003] At present, the methods for determining electrolyte concentration include flame pho...

AI Technical Summary

Problems solved by technology

[0005] This electrolyte analyzer has three disadvantages: first, the potential signal can be recorded and the sample concentration can be calculated after the electrode response reaches the equilibrium potential during static measurement, which not only increases the residence time of the blood sample in the flow-through electrode tube, but also leads to the formation of fibers in the blood sample. The coagulation of protein on the electrode film, the blockage of the pipeline, and the shortening of the life of the electrode increase the cost of instrument maintenance and the sampling time; second, when cleaning with air, the emptying of the sample in the flow cell inevitably makes the electrode sensitive membrane Periodically exposed to the air, alternating dry and wet changes the surface state of the membrane, affecting the sensitivity and stability of the electrode; moreover, the air bubbles in the system will cause electrode interference and cause measurement errors; third, the sample needle moves up and down in the reagent valve. Point movement, complex procedures, easy to cause cross-contamination of blood samples, high matching accuracy requirements between the sample needle and the cylindrical cavity in the reagent valve; fourth, there are many dead ends in the flow path of the instrument, for example, air bubbles are easy to remain in the four passage ports of the reagent valve, resulting in Electrode interference; Fifth, the bubbles released from the dissolved gas in the blood sample during the suction process will cause false response of the bubble sensor, and the use of the bubble sensor also increases the overall instrument cost

Sixth, during the sample measurement process, each step of the sample needle is executed by the operator and the instrument through interactive settings to obtain corresponding instructions, resulting in cumbersome operating procedures and a low degree of automation

[0007] figure 2 The core of the electrolyte analyzer patent shown (CN 2283853Y) is to use two single-channel solenoid valves (valve 1 and valve 2) and two single-channel peristaltic pumps (pump 1 and pump 2) set in the standard liquid flow path to control A, B standard solution and blood sample switch, enter the electrode detector through a three-way, the measurement principle is similar to the patent of Medica (UN 4705668), and the disadvantages caused by the measurement method still exist; on the other hand, it is similar to the above three patents. Compared, this patent (CN 2283853Y) splits the five-way switching valve into a three-way, two single-channel solenoid valves and two peristaltic pumps, which increases the number of components and control steps and brings more potential hidden dangers

When the blood sample is measured, the blood sample in the tee is always in contact with the B standard solution, and there is ion diffusion, which causes serious cross-contamination and increases the error of the measurement result; in addition, the designed groove-shaped liquid supply port makes the blood sample contact with the environment, which is easy to cause Contamination and oxidation of blood samples by the environment; this design is more dangerous to operators when measuring highly infectious blood samples

[0008] To sum up, the main problems existing in the existing electrolyte meter are: based on the static response balance of the electrode, the analysis speed is very slow; the blood sample stays in the system for a long time, resulting in blood sample cross-contamination; and clogging, which ultimately shorten the life of the flow-through electrode; air bubble cleaning causes dry-wet changes on the surface of the electrode sensitive membrane, resulting in changes in the sensitivity and stability of the electrode membrane; the injection volume cannot be precisely controlled, the detection steps are cumbersome, and the instrument cost is high , poor reliability, etc.

This remains a problem for automated electrolyte analysis devices

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