Laboratory Vacuum Filtration Type, Use and Construction

Laboratory vacuum filtration equipment( such as Glass Single Vacuum Filtration Assembly) is used by many universities, research institutes, biopharmaceuticals, industrial enterprises, environmental monitoring and other units. The laboratory vacuum filtration device is used as a basic tool. The main function is to fix the microporous membrane (filter paper, filter cloth or filter), and then remove the solids, particulate matter or microorganisms in the liquid through the membrane. On the membrane, to achieve the purpose of separation.

Types of Laboratory Vacuum Filtration

  1. Büchner Funnel Filtration:
    • Use: Used for routine filtration of solids from liquids. Common in organic chemistry labs.
    • Construction: Consists of a Büchner funnel (porcelain or glass) connected to a sidearm flask. A filter paper is placed in the funnel to trap solids.
  2. Filter Flask Filtration:
    • Use: Suitable for routine filtration in microbiology and general laboratory applications.
    • Construction: Involves a filter flask connected to a vacuum source, with a filter assembly (filter flask or adapter) and a membrane or filter paper.
  3. Vacuum Filtration Manifold:
    • Use: Enables multiple filtrations simultaneously, increasing efficiency.
    • Construction: Consists of a manifold with multiple ports, each connected to a filter flask. Ideal for high-throughput applications.
  4. Centrifugal Vacuum Filtration:
    • Use: Used for rapid filtration of small volumes, suitable for biological and protein samples.
    • Construction: Involves a centrifuge tube with a membrane or filter paper, placed in a rotor for centrifugation. Vacuum is applied to draw liquid through the filter.

Construction of Laboratory Vacuum Filtration

For separation purposes, a complete laboratory vacuum pumping unit should include a filter bottle set, an air pump, and a pump tube that connects them. The filter bottle set is generally divided into a filter cup, a filter placement base and a liquid collection bottle. The lack of any part will not start filtering properly. It contains the following components: one vacuum pump, one vacuum filter (300ml filter cup, sand core glass filter holder, 1000ml liquid collection bottle, aluminum fixture), connecting hose with water blocking filter One, these components are an integral part of the suction filter, and each component functions as follows:

1) Oil-free vacuum suction pump ( such as Standard Vacuum Filtration Pump, Anti-Corrosion Diaphragm Vacuum Pump): used to draw the bottom of the filter bottle into a negative pressure state, thus forming a pressure difference with the outside of the filter bottle. In general, the amount of the suction pump accounts for the majority of the filtration device. Some customers will ask if they can save the funds at the time of purchase. If the filter is small, the pore size of the filter will be greatly resistant to the liquid. Therefore, if there is no main force of the pump, the liquid permeation filter can hardly be filtered normally. Therefore, the suction pump is an essential part of the filter unit.

2) Filter cup: The filter cup is generally located at the upper part of the filter membrane and contains the filtrate to be filtered.

3) Sand core glass membrane base: This part is of great significance for the whole set of equipment. It is used to place the filter membrane. Whether the filter base design is flat, whether the surface is smooth and flat, and the aperture is uniform, it will affect the filtration end filter. The quality of the membrane, whether it leaks during filtration, also affects the filtration rate at the time of filtration. The quality of this section is very important.

4) Aluminum fixture: The fixture is used to fix the filter bowl and the filter base. Sometimes it may come into contact with the liquid. If the material is not good, it may be corroded. At present, the upper and lower positioning products will surface the fixture. Improve corrosion resistance, while ordinary products use iron fixtures.

The blue cap reagent bottle is used as the filter device of the receiving bottle to facilitate the preservation of the filtered filtrate.

5) Liquid collection bottle: The liquid collection bottle collects the filtered filtrate. This part of the customer generally selects the capacity according to the amount of filtration. However, some special filtration experiments, such as medium sterilization filtration, liquid phase mobile phase solvent filtration or other reagent sterilization and impurity filtration, because the filtrate needs to be collected and stored for later use. Designed with laboratory reagent bottles, so that the filtrate does not need to be poured out after filtration, just need to unscrew the funnel, you can save directly.

6) Hose: It is used to connect the suction filter bottle and the pump. Generally, a professional vacuum pump tube with thick wall thickness is used. If the wall thickness is too thin, it will fall off and cannot work normally. St. Stephen’s suction filter is also specially designed for hoses. A water-blocking filter is placed in the middle of the hose to prevent the problem of filtrate suction.

Common Uses

  1. Sample Preparation: Separation of solids from liquid samples for further analysis.
  2. Microbiological Filtration: Filtration of microbial cultures and particulate matter.
  3. Chemical Synthesis: Isolation of reaction products or removal of impurities.
  4. Protein and Nucleic Acid Purification: Filtration in molecular biology applications.
  5. Quality Control: Filtration for quality testing of pharmaceuticals, food, and beverages.

Laboratory vacuum filtration is a versatile technique with widespread applications across various scientific disciplines. The choice of setup depends on the specific requirements of the filtration task and the nature of the sample being processed. Proper assembly, maintenance, and adherence to safety protocols are essential for successful vacuum filtration in the laboratory.