Our high-purity Whatman™ ashless Grade 42 filter papers have the finest retention of all Whatman™ ashless filter paper grades and are designed for gravimetric analysis and sample preparation for instrumental analysis.
Ashless: 0.007% ash maximum
Fine (2.5 μm) nominal particle retention rating, eliminates large particles that might otherwise interfere with sensitive instrumentation
Herzberg filtration speed of 1870 s
Commonly used as a calcium carbonate filter
Particularly suitable for gravimetric analysis
Other typical precipitates for gravimetric analysis include barium sulfate and metastannic acid for use in glazes, coatings, and pigments. The high purity of Cytiva's Grade 42 filters also makes them suitable for processes that require ashing.
Whatman ashless™ quantitative filter papers are high-purity filters that support accurate analysis in applications sensitive to very low levels of background contamination and in gravimetric analysis where ash content might affect weight measurements of combusted samples. Cytiva's high-purity Whatman™ ashless filter papers are suited for:
Environmental analysis: soil filtration analysis, when separating solid matter from aqueous extracts
Retention of small particles
Collection of trace elements and radionuclides from the atmosphere
