Whatman™ Grade 4 Qualitative Filter Papers, Circles

The Whatman™ Grade 4 Qualitative Filter Papers are high-performance cellulose filter papers designed for fast filtration and coarse particle retention in routine laboratory applications. Known for their exceptionally high flow rate, these filters are ideal when rapid processing is required and fine particle retention is not critical.

With a nominal particle retention of 20–25 µm, Grade 4 filter papers are particularly suited for filtering coarse precipitates and gelatinous materials, making them a preferred choice for analytical, environmental, and industrial workflows.

Key Features

Extremely High Flow Rate

• One of the fastest qualitative filter papers available
• Enables rapid filtration and increased laboratory throughput
• Ideal for time-sensitive workflows

Coarse Particle Retention

• Nominal retention of 20–25 µm
• Efficiently captures:
  • Coarse particles
  • Gelatinous precipitates
• Suitable for applications where fine filtration is not required

Versatile Cellulose Composition

• Made from high-quality cellulose fibers
• Ensures consistent filtration performance
• Compatible with a wide range of chemical and biological samples

Excellent for Routine Laboratory Use

• Ideal for quick clarification and separation tasks
• Suitable for general qualitative analysis

Flexible Format Options

• Available in circular, sheet, roll, and prepleated formats
• Prepleated versions provide:
  • Faster flow rates
  • Increased loading capacity

Applications

• Fast filtration of coarse precipitates
• Filtration of ferric hydroxide and aluminum hydroxide
• Routine laboratory sample clarification
• Cleanup of biological fluids and organic extracts
• Environmental monitoring (air and particulate analysis)
• Qualitative analytical separations
• Industrial and research laboratory filtration

Technical Specifications

Available Models and Ordering Information (Selected)

Workflow Integration

Sample Preparation → Rapid Filtration (Grade 4) → Filtrate Collection → Analysis

This ensures:

• Fast separation of coarse materials
• Efficient processing of large sample volumes
• Improved laboratory productivity

Unique Advantages

• Extremely fast filtration speed for high-throughput workflows
• Ideal for coarse and gelatinous precipitate filtration
• Reduces processing time in routine laboratory applications
• Available in multiple sizes and formats for flexibility
• Compatible with a wide range of analytical and industrial processes
• Trusted Whatman™ quality for consistent results

The Whatman™ Grade 4 Qualitative Filter Papers are the ideal solution for laboratories requiring rapid filtration and efficient handling of coarse particles. With their high flow rate, robust performance, and versatility, they are an essential consumable for routine filtration, environmental analysis, and industrial applications where speed and efficiency are critical.