Cleaning method of chromatographic injection probe and how t

Although the chromatographic injection needle is small, it is indispensable. The injection needle is the way to connect the sample and the analyzer. With the injection needle, the sample can enter the chromatographic column, and the continuous spectrum can be analyzed by the detector. Therefore, the maintenance and cleaning of the injection probe is the focus of the daily needs of the analyzers, otherwise, it will not only affect the operation efficiency, but also damage the instrument.
1、 Cleaning of injection probe
1. Be able to clean the inner wall of the injection probe with organic solvent. When cleaning, please check whether the injection probe push rod can move smoothly;
2. If the push rod of the injection probe does not move smoothly, it can be taken out. It is recommended to clean it with a soft cloth dipped in organic solvent;
3. Repeat the use of organic solvent for suction. If the resistance to the injection needle push rod increases rapidly after several times of suction, it is clarified that there are still some small dirt, and the cleaning process should be repeated after this situation occurs.
4. If the injection needle push rod can move smoothly, check whether the needle is blocked. Wash the needle repeatedly with organic solvent, and check the shape of the sample being pushed out of the needle.
5. If the injection probe is normal, the sample will flow out in a straight line. If the needle is blocked, the sample will be ejected from a direction or an angle in the form of fine mist. Even if the solvent flows out in a straight line, be careful to check that the outflow condition is better than the normal condition (compare the outflow condition with a new non blocked injection probe).
6. Clogging in the needle will damage the reproducibility of the analysis. For this reason, maintenance of the needle is necessary. Remove the obstruction from the needle with something such as wire. The needle can only be used if the sample is flowing normally. The use of aspirator or syringe cleaner can also effectively remove the pollutants in the needle tube.
2、 How to avoid unsmooth injection needle
Many novices doing chromatographic analysis often bend the needle and needle rod of the syringe
1. The injection port is too tight, and it is too tight at room temperature. When the temperature of the vaporizer rises, the silicone gasket will be more tight, and it is difficult for the syringe to enter.
2. The needle is stuck in the metal part of the injection port.
3. The needle bar bending is that the injection force is too strong during injection. The imported chromatographic column is equipped with an injector rack, and the syringe rod will not be bent by using the injector rack for injection.
4. Because the inner wall of the syringe is polluted, the needle rod is bent during injection. When the syringe is used for a period of time, it will be found that there is a small black part in the needle tube close to the top. At this time, it is difficult to inject the sample. The cleaning method is to pull out the needle rod, inject a little water, insert the needle rod into the contaminated position, push and pull repeatedly, if not, inject water again until the pollutants are removed. At this time, you will see that the water in the syringe becomes turbid. Pull out the needle rod, wipe it with filter paper, and then wash it with alcohol several times. When the sample to be analyzed is a solid sample dissolved by solvent, the syringe should be washed with solvent after injection.
5. Be careful when you inject the sample. You will bend the syringe as soon as you are skilled in injection.
For more related technologies, please consult MS technologies technicians