Whatman ashless Grade 42 quantitative filter papers are suitable for a wide range of critical analytical filtration procedures for quantitative analysis. Grade 42 filter papers have the finest retention of all Whatman ashless filter paper grades. Grade 42 is designed for gravimetric analysis and sample preparation for instrumental analysis.

Features

• 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

Whatman Grade 42 quantitative papers are designed for retention of extremely small particles. A common example is use of Grade 42 as a calcium carbonate filter for analysis in the cement industry.

Other typical precipitates for gravimetric analysis include barium sulfate and metastannic acid for use in glazes, coatings, and pigments. The high purity of Whatman's Grade 42 filters also makes them suitable for processes that require ashing.

What are Whatman Ashless Quantitative Filter Papers?

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. 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