Accelerate your moisture analysis with filter paper 

Analyzing samples with high moisture content can present various challenges, often leading to long analysis times and inaccurate results. Liquid samples, in particular, can create challenges as their high moisture content means proper sample preparation and analysis are crucial for reliable results. 

Obtaining consistent, accurate, and dependable data is essential, so we propose a practical approach: incorporating filter paper. This handy accessory will increase your sample’s surface area, thereby accelerating your analysis and improving the reliability of results. 

This technical note compares the moisture analysis of water with and without filter paper, demonstrating the impact this addition can have on the speed of your analysis. 

What is a moisture analyzer? 

A moisture analyzer is a piece of equipment that analyses a sample’s moisture content by employing the loss-on-drying (LOD) method. 

It works through these simple steps. 

1. Weighing: The precisely built-in balance records the initial weight of your sample. 
2. Drying: Your moisture analyzer heats up based on the temperature you set to evaporate the moisture and determine the moisture content. 
3. Continuous weighing: Your sample is weighed throughout the full process, and automatically stops when you reach your defined stop parameters or desired stop time.  

When would I need to use filter paper? 

Using filter paper can be advantageous for most high moisture content samples as it increases the sample’s surface area, leading to faster and more dependable results.  

So, what are the benefits of using filter paper? 

• Increased Surface Area: High-moisture samples, like liquids, can form a puddle in the sample pan. The filter paper spreads the sample out thinly, creating a much larger surface area. This means more of the sample is exposed to the heat, allowing the moisture to evaporate much faster. 
• Prevents Pooling: As mentioned above, liquids can pool, which slows down drying from the bottom layer. The filter paper acts like a sponge, holding the liquid and preventing it from forming a deep pool. This ensures more even drying across your entire sample.  
• Reduces Splattering: Some high moisture samples, especially those containing fats or oils, can spatter when heated. Filter paper can help to absorb these splatters, keeping the inside of your analyzer clean and ensuring all the sample weight loss is due to moisture evaporation, leading to more accurate results.    
• Supports Even Heating: By distributing the sample evenly, the filter paper helps ensure your sample is heated uniformly throughout analysis. This leads to more consistent and accurate moisture readings.  
• Easier Handling: For very wet or sticky samples, it can be difficult to transfer and spread them evenly in the sample pan. The filter paper provides a support structure, making the sample easier to handle and distribute, which contributes to more consistent results.
   

As depicted with milk in Figure 1, filter paper offers several advantages by preventing sample pooling and increasing the sample’s surface area. This enables quicker and more precise analysis. 

Figure 1: Left-hand side image – milk was loaded onto the sample pan without filter paper underneath, resulting in uneven sample distribution on the weighing pan. Right-hand side image -Milk was loaded onto the sample pan with filter paper underneath, resulting in even sample distribution on the weighing pan. 

Real-life example: What’s the difference between using and not using filter paper on my results? 

Figure 2: Loading the sample for moisture analysis of water. The left-hand image is the sample loaded directly onto the sample pan, the right-hand image is the sample loaded using a sample pan and filter paper. 

To investigate the effect of filter paper on moisture analysis, our application scientist analyzed water samples both with and without its use. Figure 2 shows the samples before analysis, and the corresponding results are presented in Table 1.  

Table 1: Moisture analysis results of water with and without filter paper.  

Results and Conclusion 

The moisture analysis of water, both with and without filter paper, yielded the same result: 100% moisture content, as expected. However, the analysis with filter paper was five times faster than the analysis without it. This indicates that high-moisture liquid samples significantly benefit from the use of filter paper, which increases the surface area for evaporation.      

The Precisa 530 PBM moisture analyzer can accurately determine the moisture content of high moisture samples such as water. This process is significantly sped up when utilising filter paper, due to the increase in surface area.   

The Series 530 moisture analyzers: 

Our series 530 moisture analyzers offer the highest accuracy and precision, all with a sustainable approach due to our PHASTbloc weighing technology. The exciting features of our moisture analyzers include: 

• Excellent performance and accuracy for all samples, including high moisture content  

• Contains our unique PHASTblocTM hybrid weighing, providing you with a sustainable and repairable instrument 

• Automated lid opening for a fast cooldown time 

• All parts at the bottom of the heating chamber can be disassembled and reassembled by hand for easy cleaning

Piqued your interest? If your laboratory needs its moisture analyzers upgraded, the 530 Moisture Analyzer is the high-performance kit you need – contact our sales team today to find out more.