Cytiva's high-purity quartz microfiber filters are used in many air sampling filter applications, including sampling of acidic gases, stacks, flues, and aerosols. Filters are suitable for PM-10 sampling and analysis. Temperature resistant up to 800°C Binder-free Cytiva business offers three types of quartz fiber filters. Whatman quartz microfiber filters Because of the low level of alkaline earth metals, "artifact" products of sulfates and nitrates (from SO₂ and NO₂) are virtually eliminated. High-purity quartz microfiber filters are therefore applicable for particulate monitoring and heavy metal analysis. Whatman QM-A filter circles and sheets QM-A quartz microfiber filters from Cytiva come in a wide range of circle diameters, as well as 25-piece sheets. QM-A sheets (1851-8866) are sequentially numbered according to U.S. Environmental Protection Agency (EPA) standards and are suitable for most applications.