What Instrument Is Used To Measure Electrolytes?

Introduction

The fully automatic electrolyte analyzer is an instrument used to detect potassium ions, sodium ions, chloride ions, and ionized calcium (PH) from samples. The samples can be whole blood, serum, plasma, urine, dialysate, and hydration fluid. The fully automatic electrolyte analyzer is indispensable in clinical testing. In clinical practice, it mainly tests and maintains human blood.

Purpose

The fully automatic electrolyte analyzer is an automatic analytical instrument based on ion selective electrode method and pressure method, using a microprocessor to realize analysis. The instrument can quickly and accurately analyze the content of potassium, sodium, chloride, and calcium ions in serum, as well as pH value and TCO2 size, calculate the anion gap (AG), and the measurement results are directly displayed on the LCD and printed on the built-in printer. The instrument has high precision and accuracy, and the results measured for any sample are accurate, reliable, fast, and simple to operate. Therefore, ion detection is a necessary general equipment for hospitals at all levels.

Working Principle

The fully automatic electrolyte analyzer uses ion selective electrode measurement to achieve accurate detection. There are six electrodes on the instrument: sodium, potassium, chloride, ionized calcium, lithium and reference electrode. Each electrode has an ion selective membrane that reacts with the corresponding ions in the sample being tested. The membrane is an ion exchanger that reacts with the ion charge and changes the membrane potential, which can detect the potential between the liquid, sample and membrane. The two potential differences detected on both sides of the membrane will generate current. The sample, reference electrode, and reference electrode liquid form one side of the "loop", and the membrane, internal electrode liquid, and internal electrode are the other side.

The ion concentration difference between the internal electrode liquid and the sample will generate an electrochemical voltage on both sides of the membrane of the working electrode. The voltage passes through the highly conductive internal The electrode is connected to the amplifier, and the reference electrode is also connected to the location of the amplifier. The calibration curve is obtained by detecting a standard solution with a precise known ion concentration, so as to detect the ion concentration in the sample.

When the measured ions in the solution contact the electrode, ion migration occurs in the aquifer of the ion selective electrode matrix. The charge change of the migrated ions has an electric potential, which changes the potential between the membrane surfaces and generates a potential difference between the measuring electrode and the reference electrode.

Operation method

1. The instrument is turned on to enter the system self-test to detect whether the functions of the main components are normal, such as: instrument mainboard, printer, liquid circuit detection (completed by liquid detector), distribution valve and valve detector, etc., which can intelligently identify and judge faults and automatically prompt.

2. Enter the activation electrode program, which has the electrode activation timing function, accurately grasp the activation time, so as to increase the service life of the electrode and ensure the stability of the electrode. The time is a 30-minute countdown, and the NO key can be pressed to directly exit the activation electrode program.

3. Enter the main menu, first perform system calibration, and automatically select the base point and slope calibration (you can also choose to exit without calibration, which is convenient for maintenance, but you cannot directly measure serum samples)

4. Select quality control analysis. After more than 5 quality control tests, the quality control report can be automatically generated and printed, and the average value, standard deviation, and coefficient of variation of the quality control times can be calculated.

5. Intelligent liquid detection program to ensure accurate injection and measurement, automatic prompts during the measurement process, your convenient guide, 24-hour standby, automatic maintenance in standby state, automatic forward and reverse flushing function, short liquid path, unique forward and reverse flushing automatic calibration and flushing pipeline system, to prevent cross contamination and pipeline blockage.

6. 30-hole automatic injection system, with quality control M hole and waste liquid W hole. 30 specimens can be tested at a time.

7. Automatic printing and manual printing are optional to save printing paper. Report sheet: patient comprehensive information report, you can set the normal range value of the human body and print it.

8. Test samples: whole blood, serum, plasma, urine, body fluids, cerebrospinal fluid, urine, animal serum, etc.

9. Measurement method: ion selective electrode (ISE) direct method.

10. Test items: K+, Na+, Cl-, Ca++, PH, CO2

Fault handling

1. How to solve the problem when the detector fails

① The plug of the detector is loose with the main board seat;

② The detector itself is broken;

③ The fixing screws on the valve core and the motor shaft are not tightened in place;

④ The valve core itself is too tight to rotate. The order of inspection is ③-①-④-②.

2. Causes and treatment methods for poor sample aspiration:

① Check whether the connecting tubes of each interface of the pipeline (including the connecting tubes between electrodes, between electrodes and valves, and between electrodes and pump tubes) are leaking. This phenomenon is manifested as no sample aspiration;

② Check whether the pump tube is sticky or too fatigued. At this time, a new pump tube should be replaced. The phenomenon is manifested as abnormal sound from the pump tube;

③ There is protein precipitation in each pipeline, especially at each joint. This phenomenon is manifested as unstable positioning of the liquid flow velocity process, even if a new pump tube is replaced. The solution is to remove each joint and clean it with water.

④ There is a problem with the valve itself, so check it carefully.

3. Causes and treatment of electrode drift and loss of control

① The most common cause of electrode drift is that the ground wire is not connected properly, so check the ground wire; check whether the drifting electrode silver rod is not inserted into the signal socket or has poor contact;

② The voltage is unstable, so it is best to connect to a UPS uninterruptible power supply or a high-quality stabilized power supply (a poor-quality stabilized power supply will cause electrode drift);

③ Avoid electromagnetic interference, and equipment with high power should be kept away from this instrument as much as possible, and set up an independent power supply;

④ Check whether the standard solution and cleaning solution have been used up; check whether the reference filling solution in the circulation pool is too little, and fill it up in time;

⑤ When the Na and pH electrodes drift, they should be cleaned with glass electrode cleaning solution. Then rinse repeatedly with distilled water;

⑥ If all electrodes drift, check whether the reference electrode has expired;

⑦ The positioning is not good, resulting in the solution not completely immersing the electrode, and the positioning operation should be re-performed;

⑧ If there are bubbles above the reference electrode, tap the circulation pool to move the bubbles above the Na electrode;

⑨ The reagent is expired or contaminated, check whether there is flocculent precipitation in the A, B standard solution and cleaning solution bottles.

4. How to deal with the decrease in electrode slope:

① Too much protein adsorbed on the electrode membrane;

② The air humidity is too high;

③ The temperature is too low;

④ The life is coming to an end.

In the fourth case, the user needs to replace the electrode. The first one can be treated with protein removal solution. Na and pH electrodes have special cleaning solutions. The other electrodes can be treated with protein cleaning solution prepared by dissolving a piece of protease in 30ml 0.1M hydrochloric acid. Use the first cleaning function of the service program to repeatedly clean and remove the protein, and then rinse with PVC cleaning solution several times. After calibration and stability, measure the sample.

The second and third situations mainly affect the Na and pH electrodes. If the air humidity is too high, a dehumidifier should be used for dehumidification; if the temperature is too low, the room temperature can be raised. If these two conditions are not met, the Na electrode, pH electrode, and signal board can be heated and dehumidified with a hair dryer before measurement.

5. Causes and solutions for abnormal values in blood sample testing

① Are there high-power electrical appliances turned on or leaking electricity (such as centrifuges and refrigerators) nearby, causing voltage fluctuations;

② Inhalation of coagulated blood during testing;

③ If the solution is not in place, check whether the positioning is good. If the solution is not in place, the repositioning program in the service program can be used to reposition it;

④ Check whether the container containing the blood sample is contaminated and whether there are residual substances such as disinfectants;

⑤ Check whether the correction factor is correct. If there is an abnormality, the correction factor can be cleared;

⑥ If it has not been calibrated for a long time, it can be recalibrated before testing.