Comparison of Quantitative and Qualitative Filter Paper

Hawach qualitative filter paper is generally gravity-filtered, and solid-liquid separation is carried out using filter paper to retain solid phase particles.

The filter paper is usually used in a single layer or a plurality of layers. Filter paper has natural mechanical strength and certain toughness. If you need to speed up the filtration speed, you can fold the filter paper multiple times. For example, stacking two layers of filter paper into a fan shape or a tie pattern can significantly increase the filtration speed. When filtering the air pump, 2-3 layers of filter paper can be stacked in the funnel according to the pumping force, or a dense filter cloth should be placed first, and the filter paper is filtered on top. Highly corrosive concentrated nitric acid and concentrated sulfuric acid solutions should not be filtered by ordinary filter paper.

Similarity

Both the quantitative filter paper and the qualitative filter paper are cellulose filter papers and are not suitable for other types of filter paper, such as glass microfiber filter paper.

Nitrocellulose membrane filter

Difference between qualitative and quantitative filter paper

CategoryQuantitative Filter PaperQualitative Filter Paper
PurposeUsed for quantitative analysis and gravimetric analysis.Used for general qualitative analysis and filtration of precipitates.
CompositionMade of high-quality alpha-cellulose fibers.Made of a mixture of cellulose and lignin fibers.
Ash ContentVery low (≤ 0.0009%); almost ash-free.Higher (≤ 0.13%) compared to the quantitative paper.
Pore Size and Particle RetentionVery fine; retains particles < 2 microns.Larger pores; retains particles > 8 microns.
ApplicationsAir pollution monitoring, wastewater, and soil analysis.Food and beverage analysis, blood analysis, pharmaceutical analysis, laboratory cleaning, and wiping.
Filtration Speed CategoriesTypically uniform and fine filtration.Divided into fast, medium, and slow (based on particle size and filtration speed).
ExamplesAshless filter paper.BIO-4, Grade 113 (fast); Grade 1, BIO-2, Grade 91 (medium); BIO-5, BIO-6 (slow).
Post-Ashing ResidueFixed, negligible residue; crucial for accurate weighing.Residue relatively higher; not suitable for precise gravimetric analysis.
Special TreatmentPulp treated to remove most impurities (e.g., with hydrochloric and hydrofluoric acid).Less extensive impurity removal compared to quantitative papers.

Qualitative filter papers, on the other hand, are designed for general qualitative analysis and are used to separate precipitates from liquids. They are made of a mixture of cellulose and lignin fibers, which gives them a higher ash content than quantitative filter papers. They have a relatively larger pore size than quantitative filter papers, allowing them to retain larger particles, with a diameter greater than 8 microns. Qualitative filter papers are commonly used in applications such as food and beverage analysis, blood analysis, and pharmaceutical analysis. Qualitative filter paper is also commonly used to clean the test bench and various equipment tools in the cleaning and wiping laboratory.

Qualitative filter paper is divided into three speeds: fast, medium, and slow. Fast moisture breakage ≥120, the separation performance of iron hydroxide, high loading, suitable for filtration of coarse particles, medium, and gelatinous precipitates. The medium-speed moisture breakage is ≥140, the separation performance is lead sulfate, medium separation performance, medium filtration speed, liquid filtration covering most laboratory applications, and medium-speed filter paper is often used in industrial filtration. The slow moisture-resistant breaking degree is ≥180, and the separation performance is barium sulfate (heat). Retention is strong, adsorption is obvious, and particles can be intercepted to a large extent, but this takes a long time.

Hawach’s Qualitative filter papers BIO-4 and Wet Strengthened Grade 113 Filter Paper are fast; Qualitative Lab Filter Paper Grade 1, BIO-2, and Buchner Funnel Filter Paper Grade 91 are medium-speed filter papers; BIO-5 and Qualitative Cellulose Filter Paper: BIO-6 are slow-to-filter papers.

Quantitative filter papers are designed for quantitative analysis and are used to collect and measure particulate matter. They are made of high-quality alpha-cellulose fibers, which are almost free from ash content. They have a low ash content, which makes them ideal for gravimetric analysis. These papers have a very fine pore size that allows them to retain particles with a diameter of fewer than 2 microns. Quantitative filter papers are commonly used in applications such as air pollution monitoring, wastewater analysis, and soil analysis.

Quantitative Medium Flow Filter Paper Grade: BIO-40, Quantitative Ashless Filter Paper Grade: BIO-41, Quantitative Laboratory Filter Paper Grade: BIO-42, Quantitative Cellulose Filter Paper Grade: BIO-44, Wet Strengthened 10 Micron Filter Paper Grade: BIO-91, Wet Strengthened Chemistry Filter Paper Grade: BIO-113.

Qualitative vs Quantitative Filter Paper. In summary, the main differences between quantitative and qualitative filter papers are their composition, pore size, and filtration properties. Quantitative filter papers are made of high-quality alpha-cellulose fibers, have a low ash content, and have a very fine pore size that allows them to retain particles with a diameter of fewer than 2 microns. Qualitative filter papers are made of a mixture of cellulose and lignin fibers, have a higher ash content, and have a relatively larger pore size that allows them to retain particles with a diameter greater than 8 microns. Qualitative filter paper is used for qualitative chemical analysis and corresponding filtration separation; quantitative filter paper is used for gravimetric analysis tests and corresponding analytical tests in quantitative chemical analysis.

The function of the quantitative filter paper is mainly used for the ashing weighing analysis experiment after filtration. The ash weight of each filter paper after ashing is a fixed value.

The qualitative filter paper is used for general qualitative analysis and filtration of precipitates and suspensions in solution. While the amount of ash generated after ashing differs from that of the quantitative and qualitative filter paper. The qualitative filter paper does not exceed 0.13%, and the quantitative filter paper does not exceed 0.0009%.

Quantitative vs qualitative filter paper. Ashless filter paper is a quantitative filter paper with an ash content of less than 0.1 mg, which is negligible on the analytical balance. Because the qualitative filter paper’s pulp is treated with hydrochloric acid and hydrofluoric acid, and washed with distilled water to remove most of the impurities in the paper fibers.