How Many Different Grades for Hawach Ashless Quantitative Filter Paper?

Produced under strict control with high-quality cotton lint as raw material, HAWACH ashless quantitative filter papers are ideal for a variety of important analytical filtration steps, such as the gravimetric analysis to make sure the results are accurate.

In HAWACH, there are five grades of ashless quantitative filter papers, BIO-0, BIO-1, BIO-2, BIO-3, and BIO-4.

GradeParticle retentionSurfaceSpeedAshWet Burst
BIO-408.0μmSmoothMedium<0.007%>180
BIO-4120-25μmSmoothFast<0.007%>180
BIO-422.5μmSmoothSlow<0.007%>200
BIO-4316μmSmoothMedium to Fast<0.007%>180
BIO-443μmSmoothSlow<0.007%>200

BIO-40: 8μm
It’s HAWACH Classical ashless filter paper with medium particle retention and flow rate, which has a wide range of applications. The typical applications include laboratory gravimetric analysis such as cement, clay, iron and steel products; atomic absorption spectrophotometry filtration of the solution before the assay, filtration in soil analysis, etc. It can also be used for high-purity filtration collection of trace elements and radioactive elements in atmospheric monitoring. One box with 100 pcs round filter papers are available.

BIO-41: 20-25μm
With the largest particle retention, it’s the fastest flow ashless filter paper, which is often used in the analysis of large particles such as aluminum hydroxide or ferric hydroxide or for the filtration of gel precipitates. In quantitative air pollution analysis, it can be used as an adsorbate when measuring gaseous compounds at high flow rates. One box with 100 pcs round filter papers are available.

BIO-42: 2.5μm
It’s a kind of medium-speed filter paper with the smallest retained particles in the HAWACH cellulose filter paper, a standard filter paper for the world’s evaluation of constant gravimetric analysis. It is frequently used in analysis of fine particle precipitates such as barium, metatin, and carbon calcium. One box with 100 pcs round filter papers are available.

BIO-43: 16μm
The retention is between BIO-40 and BIO-41 filter paper, and the filtration speed is twice that of BIO-40 filter paper. It’s suitable for sample collection in food analysis, soil analysis, air pollution monitoring and inorganic analysis in the construction, mining and steel industries. One box with 100 pcs round filter papers are available.

BIO-44: 3μm
The ash content of BIO-44 filter paper is lower than that of other filter papers in this series, and the efficiency of collecting particles is slightly lower than that of BIO-42, but the flow rate is almost twice that of BIO-42. The round filter paper is packaged in a box of 100 pieces.

BIO 541: 22μm
In addition to the above five grades, there is also a special one Grade 541 : 22μm. It’s  hardened for high wet strength and chemical resistance, such as the rapid filtration of large particles and colloidal precipitates in acidic or alkaline solutions for specific gravity analysis. The tough surface makes these filters suitable for a variety of demanding filtration steps.

Typical applications include fiber determination in animal food, gel determination in milk and cream, chloride analysis in cement, and determination of chlorine and phosphorus in coal and coke. It is also used for the determination of soybean protein in meat by enzyme-linked immunosorbent assay and the determination of ascorbic acid by titration. In terms of ambient air pollution, due to the high flow rate and extremely low chemical background of filter paper, it can be used for atmospheric particulate matter sampling and heavy metal element analysis, such as hexavalent chromium (Cr6+), lead, mercury, arsenic, copper, etc. It can also be used for fluoride, Sampling of ammonia pollutants, lead, mercury, arsenic, etc.