Whatman Grade 40 high-purity filters from Cytiva's business are general-purpose papers for quantitative analysis. Grade 40 filters are suitable for a variety of analytical filtration applications.

• High-purity filters contain 0.007% maximum ash content
• Medium nominal particle retention rating of 8 µm
• Medium filtration speed (Herzberg 340 s)
• Particularly useful for gravimetric analysis

High-purity filters 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 Grade 40 ashless paper is suited to:
- Soil analysis, when separating solid matter from aqueous extracts
- Quantitative determination of milk sediment
- Use as a clean-up filter for solutions prior to atomic absorption (AA) spectrometry
- Analysis of constituent components in cements, clays, iron, and steel products
- Collection of trace elements and radionuclides from the atmosphere