Cytiva Whatman Grade 4 qualitative filter paper 70mm

Cytiva Whatman Grade 4 qualitative filter paper 70mm

Qualitative filter paper

Whatman's qualitative filter paper can be used for qualitative analysis to identify and recognize substances. GE also provides pre folded qualitative filter paper, which can increase the flow rate and load capacity of the filter paper compared to ordinary filter paper when folded.

No.1: 11 μ m*

No.1 filter paper is a widely used filter paper in conventional applications, with medium flow rate and cutoff particle size, which can cover most laboratory applications and is often used for clarifying liquids. The traditional application of No.1 filter paper is the qualitative analysis and separation of precipitates such as lead sulfate, calcium oxalate (thermal), and calcium carbonate.

In the agricultural field, No.1 filter paper is commonly used for soil analysis and seed testing. In the field of food industry, No.1 filter paper can be used for the separation of solids and liquids in food, or for extracting liquids, and is also widely used for simple qualitative analysis and separation in teaching.

In the field of air pollution monitoring, circular filter paper or filter paper rolls can be used to collect atmospheric dust in airflow and determine pollution intensity using optical detection methods. For gas detection, quantitative testing can be carried out through optical color reaction using test strips impregnated with color reagents. 1/2 pre folded filter paper is 1V.

No.2: 8 μm*

Compared with No. 1 filter paper, the retention rate and load capacity are slightly higher, and the filtration time is correspondingly increased (such as slower filtration speed). In addition to being able to intercept small particles around 8 μ m, its strong adsorption capacity also has its advantages. For example, No. 2 filter paper can be used as plant growth test paper, which can intercept nutrients in the soil and continuously provide nutrients for plant growth. Filter paper No. 2 is also used in atmospheric and soil testing to monitor specific pollutants. 1/2 pre folded filter paper is 2V.

No.3: 6 μm*

The thickness of filter paper No. 3 is twice that of filter paper No. 1, and it has two characteristics: it can intercept fine particles and excellent load capacity (intercepting more particles without clogging). The wet strength of filter paper increases with the increase of paper thickness, which makes No. 3 filter paper suitable for the B ü chner Buchner funnel. When using No. 3 filter paper as a sample carrier, its high adsorption characteristics come into play.

No.4: 25 μm*

The No. 4 filter paper has the ability to quickly filter coarse particles and colloidal precipitates such as iron hydroxide and *, as well as excellent retention. Very suitable for rapid filtration of organic extracts in the clarification or analysis of conventional biological reagents. It is also suitable for monitoring air pollutants with high flow rate requirements, but the interception of fine particulate matter is not the focus at this time. 1/2 pre folded filter paper is 4V.

No.5: 2.5 μm*

Number 5 is the filter paper that can intercept particles to a certain extent among all qualitative filter papers. In chemical analysis, it can trap fine particles. Low flow rate has excellent separation and clarification ability for turbid suspensions in water quality and soil analysis. 1/2 pre folded filter paper is 5V.

No.6: 3 μm*

The particle size of filter paper No. 6 is similar to that of filter paper No. 5, but the flow rate is twice that of filter paper No. 5. Often used for detecting boiler water.

Cytiva Whatman Grade 4 qualitative filter paper 70mm