Filter Paper Grade 43 (16 µm)

When laboratory workflows need both speed and acceptable quantitative accuracy

In routine analytical laboratories, filtration is often constrained by two competing factors: filtration speed and particle retention accuracy.

Filter Paper Grade 43 is designed as a practical balance between fine-retention quantitative grades (Grade 42 / Grade 40) and high-throughput filtration media (Grade 41). It delivers sufficient analytical reliability while significantly improving processing speed for everyday laboratory workflows.

What Filter Paper Grade 43 actually is?

Filter Paper Grade 43 is an ashless quantitative cellulose filter paper manufactured from high-purity cotton linters under controlled production conditions.

From a laboratory classification perspective, it belongs to: medium-fast flow ashless quantitative filtration media.

It is designed for workflows where:

• moderate-to-high particle retention (~16 µm) is required
• filtration speed must support routine laboratory throughput
• low ash content (≤ 0.008%) is necessary for gravimetric analysis

With a nominal retention of approximately 16 µm, Grade 43 sits between Grade 40 (~8 µm) and Grade 41 (~20 µm), offering a balanced position in the quantitative filter paper series.

Real laboratory behavior (why Grade 43 is selected)

In practical laboratory environments, filter paper performance is evaluated by operational efficiency and acceptable analytical trade-offs rather than specification alone.

Intermediate particle retention stability

Grade 43 retains most routine suspended solids while allowing faster flow compared to fine-retention grades.

Improved batch processing throughput

Compared with slower quantitative grades, it significantly reduces filtration time in routine and high-volume workflows.

Acceptable gravimetric reliability

Low ash content ensures weighing accuracy is maintained in standard quantitative analysis without introducing measurable bias.

Grade 43 is selected because it provides a practical balance between analytical precision and operational speed.

Typical scenarios where Grade 43 is adopted

In these workflows, Grade 43 becomes a cost-effective and high-efficiency quantitative filtration standard.

Technical Specifications

Typical applications

• Food analysis and quality control testing
• Soil and sediment routine analysis
• Environmental monitoring and water testing
• Mining, cement, and metallurgy sample filtration
• Gravimetric analysis with moderate precision requirements
• Pre-filtration for ICP / ICP-MS / AAS sample preparation

Selection logic (how laboratories actually decide)

Grade 43 is the optimal compromise for laboratories that require both operational efficiency and acceptable quantitative accuracy.

Analytical performance considerations

Grade 43 is widely used in workflows where:

• moderate precision is acceptable for gravimetric analysis
• batch processing efficiency is important
• low ash content is required to avoid measurement bias
• filtration consistency across samples is needed

In practical laboratory systems, Grade 43 is considered a workflow optimization filter paper rather than a high-resolution analytical barrier.

Equivalent grade reference

Ordering information

Download PDF Datasheet

FAQ

Why use Grade 43 instead of Grade 40 or Grade 41?

Grade 43 offers faster filtration than Grade 40 while providing better particle retention than Grade 41, making it ideal for balanced workflows.

Is Grade 43 suitable for gravimetric analysis?

Yes, for routine gravimetric analysis where ultra-fine particle retention is not required.

Can Grade 43 be used for ICP / AAS preparation?

Yes. It is widely used for pre-filtration to reduce particulate load before instrumental analysis.