Our ready-to-use, Grade 934-AH RTU Whatman Glass Microfiber Filter Papers are the time-saving version of GE’s 934-AH glass microfiber Filter papers, which are widely used for dissolved, suspended and volatiles solids An analysis. They have been prewashed, dried (or ignited), desiccated and weighed, which eliminates the pre-treating steps that are otherwise required by the US EPA Laboratory Standard Method 2540 parts C, D, and E.