What Is a Filter Paper Used For?

Filter paper is a versatile and commonly used laboratory material with the primary purpose of separating solids from liquids or gases. It is made from cellulose fibers and is available in various grades, each tailored to specific applications. Here are some common uses of filter paper:

  1. Filtration of Suspended Solids:
    • The most common use of filter paper is to separate suspended solids from liquids through a process called gravity filtration. The liquid passes through the filter paper, leaving behind the solid particles.
  2. Qualitative Analysis:
    • Filter paper is often used in qualitative analysis techniques to separate and identify substances in a sample. This can include separating precipitates from a solution for further analysis.
  3. Quantitative Analysis:
    • In quantitative analysis, filter paper can be used for gravimetric analysis, where the mass of the retained solid is measured to determine the concentration of a particular substance in a sample.
  4. Air and Gas Filtration:
    • Filter paper can be used for filtering particulate matter from air or gases. This is commonly done in air pollution monitoring, microbiological air sampling, or in processes where clean air is required.
  5. Sample Preparation:
    • Filter paper is often used in sample preparation for analytical techniques such as chromatography or spectrophotometry. It helps remove impurities or particulate matter from the sample.
  6. Microbiological Analysis:
    • In microbiology, filter paper is used for techniques such as membrane filtration to separate bacteria or other microorganisms from liquids. This is common in water quality testing.
  7. Laboratory Experiments:
    • Filter paper is a staple in many laboratory experiments where the separation of solids from liquids is required. It is particularly useful in chemistry, biology, and environmental science labs.
  8. Oil and Grease Analysis:
    • Filter paper can be used in methods for determining the concentration of oil and grease in water samples. The filter paper captures the lipids, which can then be measured.
  9. Chromatography:
    • Filter paper is used as a stationary phase in paper chromatography. It helps separate and analyze different components of a mixture based on their solubility and migration rates.
  10. Drying Samples:
    • After filtration, filter paper is often used to facilitate the drying of collected samples. The paper absorbs excess liquid, allowing the solid residue to dry more quickly.
  11. Absorption of Liquids:
    • Filter paper is sometimes used to absorb excess liquid from samples. This is particularly useful in blotting techniques, such as Western blotting in molecular biology.
  12. Laboratory Cleaning:
    • Filter paper can be used for cleaning laboratory glassware. It is often employed to wipe or blot surfaces to remove residues or contaminants.
  13. Demonstration and Teaching:
    • Filter paper is frequently used in educational settings for teaching basic principles of filtration and separation techniques.
  14. Coffee Filtration:
    • In non-laboratory settings, filter paper is commonly used in coffee makers to separate coffee grounds from the brewed coffee.
  15. Liquid Transfer:
    • Filter paper can be used as a convenient medium for transferring liquids, especially in small quantities, during various laboratory procedures.

Filter paper comes in different pore sizes, thicknesses, and materials, allowing it to be selected based on the specific needs of the application. The choice of filter paper depends on factors such as the size of particles to be filtered, the nature of the sample, and the intended analysis or separation technique.

Filter paper is a kind of paper that is used in many industries now. And this kind of paper also plays a role in filtering. As we know the filter paper can be divided into qualitative filter paper and quantitative filter paper. Qualitative filter paper is a filter paper commonly used in laboratories to filter mat beakers for qualitative analysis. Quantitative filter paper is also called ashless filter paper. High-quality quantitative filter paper can replace non-phosphorus filter paper.

hawach-filter-papers-bio-42

Qualitative BIO-1 filter paper
·Particle retention – 11um
·Flow rate – medium speed
·Specifications – 10mm to 500mm diameter discs and 460*570mm rectangles

Application

a. Liquid Filtration
b. Qualitative separation
c. Soil Analysis and Seed Testing
d. Separation of solid food from liquid
e. Air pollution monitoring
f. Test gas after soaking with reagent

Qualitative BIO-2 filter paper
·Particle retention – 8um
·Flow rate – medium speed

Application

a. Monitoring of specific substances in the air
b. Soil test
c. Preserving soil nutrients in plant cultivation experiments
d. Determination of vitamin C in food, histidine in canned fish, full-fat content in meat collection, and monitoring of chromic acid mist around the spray bath
e. Textile dye quality inspection

lab grade filter paper

Qualitative BIO-3 filter paper: high load capacity and high wet strength
·Particle retention – 6um
·Flow rate – medium speed

Application

a. Buchner funnel filtration
b. The carrier of the sample, such as the collection of blood samples before separation
c. Macromolecular radioanalysis by scintillation counting
d. Determination of metal and organic wastes in water flows (from rivers, lakes, sewers, polycyclic hydrocarbons in air)

Qualitative BIO-4 filter paper: coarse particle retention and gel filtration
·Particle retention – 20-25um
·Flow rate – fast

Application

a. Monitoring air pollution with reagent immersion
b. Rapid routine purification filtration of biological fluids or organic extracts – such as fats
c. Determination of volatile acids in oils and fats, maltose in flour, sodium citrate in pharmaceuticals

filter paper priceQualitative Filter Paper BIO-5: Qualitative Filtration of the Finest Particles
·Retention -2.5um
·Flow rate – slow

Application

a. Clarify turbid suspensions and water
b. Soil analysis

Wet Strengthened BIO-91 filter paper: wrinkled side
·Particle retention -> 10um
·Flow rate – medium speed
·Application: Sugar Analysis in Glycan

Wet Strengthened Filter Paper BIO-113: Wrinkled Surface
·Particle retention – 30um
·Flow rate – fast

Application

a. Coarse particle or gel precipitation filtration
b. Vacuum filtration of viscous liquids

Quantitative BIO-40 filter paper: medium particle retention
·Particle retention: 8um
·Flow rate: medium speed

Application

a. Specific gravity analysis of cement, clay/iron, and steel product components
b. Solids are separated from the aqueous extract during routine soil analysis
c. Specific gravity analysis of milk deposits
d. Clarification filtration of solution before atomic spectroscopy detection
e. Collection of trace elements and radionuclides from the atmosphere

Quantitative BIO-41 filter paper:
·Particle retention: 20-25um
·Flow rate: fast

Application

a. Filtration of coarse particles and gel precipitates
b. Rapid determination of gas compounds by soaking paper strips during specific gravity analysis of air pollution

Quantitative BIO-42 filter paper: fine particle retention
·Particle retention: 2.5um
·Flow rate: slow

Application

– Specific gravity analysis of precipitates such as barium sulfate, stannic acid, and finely precipitated calcium carbonate

Quantitative BIO-43 filter paper
·Particle retention: 16um
·Flow rate: medium speed

Application

a. Food Analysis
b. Soil analysis
c. Particle collection in air pollution monitoring in preparation for subsequent X-ray fluorescence detection
d. Inorganic analysis for construction, mining, and steel industries

Quantitative BIO-44 filter paper
·Particle retention: 3um
·Flow rate: slow
·Application: Retention of very fine particles