HPLC pretreatment - filtering particulate source
At present, HPLC has become an indispensable analytical instrument. In order to improve the reliability of the data and extend the life of the HPLC, filtration is quite necessary. The following three main sources of particulate matter during liquid phase pretreatment filtration are described below.
I. The necessity of filtration Any particulate matter enters the HPLC system and is blocked by the sieve plate at the inlet end of the column. The final result is that the column is clogged, which is characterized by an increase in system pressure and deformation of the chromatographic peak. Therefore, various precautions, including operating procedures and the instrument's own filtration design, are required to minimize particulate matter entering the HPLC system, thereby extending instrument and column life and increasing data reliability.
Second, the main source of particulate matter There are three main sources of particulate matter: mobile phase, the sample to be tested and the wear of the instrument system components.
1. Mobile phase If the mobile phase consists of high performance liquid chromatography grade solvents, the mobile phase does not need to be filtered. This is because high performance liquid chromatography grade organic solvents, such as acetonitrile, methanol, etc., have been filtered through a 0.2 μm microporous membrane during the manufacturing process. Similarly, whether you are buying HPLC grade water or water used in an ultrapure water purification system in the laboratory, the final step is through a 0.2 μm microporous membrane.
2. Sample to be tested The second source of particulate matter in the liquid phase system is the sample to be tested. Some laboratories prior to placing their samples on the autosampler tray (or manual injection), all samples were first filtered through a 0.45 μm syringe filter. This is a method to effectively remove particulate matter from the sample being tested. However, there is a problem in this process: the use of a syringe filter, the sample to be tested through the filter, there will always be more or less loss. Mainly from such aspects: adsorption of the filter membrane, adsorption on the particles filtered by the filter, leakage of the filter between the syringe filter and the syringe. In the actual analysis, generally, each group of samples will be tested with an external standard. Therefore, as long as the signal-to-noise ratio obtained at the final detection can meet the detection limit, this step can be regarded as a systematic error and ignored.
3. Abrasives of instrument system components Another major source of particulate matter in the HPLC system is the wear of the infusion pump seal and the injection valve rotary shaft. Of course, the seal of the infusion pump and the seal of the rotating shaft will increase the amount of abrasive in the mobile phase, accelerating damage to these components. Regardless of the source of the particles, they should be removed during the experiment.
I. The necessity of filtration Any particulate matter enters the HPLC system and is blocked by the sieve plate at the inlet end of the column. The final result is that the column is clogged, which is characterized by an increase in system pressure and deformation of the chromatographic peak. Therefore, various precautions, including operating procedures and the instrument's own filtration design, are required to minimize particulate matter entering the HPLC system, thereby extending instrument and column life and increasing data reliability.
Second, the main source of particulate matter There are three main sources of particulate matter: mobile phase, the sample to be tested and the wear of the instrument system components.
1. Mobile phase If the mobile phase consists of high performance liquid chromatography grade solvents, the mobile phase does not need to be filtered. This is because high performance liquid chromatography grade organic solvents, such as acetonitrile, methanol, etc., have been filtered through a 0.2 μm microporous membrane during the manufacturing process. Similarly, whether you are buying HPLC grade water or water used in an ultrapure water purification system in the laboratory, the final step is through a 0.2 μm microporous membrane.
2. Sample to be tested The second source of particulate matter in the liquid phase system is the sample to be tested. Some laboratories prior to placing their samples on the autosampler tray (or manual injection), all samples were first filtered through a 0.45 μm syringe filter. This is a method to effectively remove particulate matter from the sample being tested. However, there is a problem in this process: the use of a syringe filter, the sample to be tested through the filter, there will always be more or less loss. Mainly from such aspects: adsorption of the filter membrane, adsorption on the particles filtered by the filter, leakage of the filter between the syringe filter and the syringe. In the actual analysis, generally, each group of samples will be tested with an external standard. Therefore, as long as the signal-to-noise ratio obtained at the final detection can meet the detection limit, this step can be regarded as a systematic error and ignored.
3. Abrasives of instrument system components Another major source of particulate matter in the HPLC system is the wear of the infusion pump seal and the injection valve rotary shaft. Of course, the seal of the infusion pump and the seal of the rotating shaft will increase the amount of abrasive in the mobile phase, accelerating damage to these components. Regardless of the source of the particles, they should be removed during the experiment.
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