About the Quality Detection Method of Quantitative Filter Paper
HAWACH provides customers with a variety of special experimental products to meet the different experimental needs of experimenters. These products combine ease of operation, high accuracy, and good consistency. Its quantitative filter papers are designed for sample preparation in gravimetric and instrumental analysis. For specific needs, HAWACH offers three filter papers for quantitative analysis: ashless, hardened low ash and hardened ashless with slow, medium and fast speed.
Quantitative filter paper
The pulp of quantitative filter paper is made after soaking in hydrochloric acid and hydrofluoric acid, and the content of iron, aluminum and silicon in the paper is very low. In quantitative analysis, this weight is negligible, so it is often referred to as “ashless filter paper”. The filtration speed of quantitative filter paper is divided into fast, medium and slow, and the filter paper box is marked with paper strips of different colors. The pore size of quantitative filter paper is generally as follows.
Fast speed: The pore size is 80-120 microns
Medium speed: pore diameter 30-50 microns
Slow speed: The pore size is 1 to 3 microns
Quality detection method
The quality detection method of quantitative filter paper is as follows:
Quality control for quantitative filter paper is crucial to ensure that it meets the required standards for analytical work. Here are some common methods used for quality detection:
- Weight Measurement: This is one of the most straightforward methods. A sample of filter paper is weighed before and after filtration. The weight gain should ideally be zero, indicating that the filter paper doesn’t contribute to the mass of the sample.
- Ash test: Weigh 10 ashless filter papers accurately, tear two of them into pieces, and put them into two accurately weighed platinum crucibles. Start heating on a warm fire in a high temperature furnace, then add high heat. After cooling, the crucible was cooled to room temperature in a desiccator and weighed. The average weight of ash in each filter paper can be obtained by subtraction.For the test of retaining barium sulfate, heat 20ml of sulfuric acid to boiling, slowly add 20ml of barium chloride solution of equal concentration dropwise at a speed of 1ml/s, and continue to heat after the dropwise addition. After 30 seconds, filter the mixture with filter paper, and observe whether there is a white precipitate in the filter paper, which can indicate whether the filter paper can retain barium borate.If starch is present in the starch test strip, it cannot be used for carbohydrate analysis. The method to check whether there is starch in the filter paper is to tear the filter paper open, azeotrope it with distilled water, and add 0.01N dilute iodine solution dropwise. If it is blue, it means there is starch. Test for iron in slow quantitative filter paper Add one drop of ammonium paper solution and one drop of hydrochloric acid to the filter paper. Without iron, there would be no brown spots.
- Filtration Speed: The time it takes for a known volume of water to pass through a specified area of the filter paper can be measured. This is important because some applications require rapid filtration.
- Pore Size Measurement: The pore size distribution of the filter paper can be analyzed using techniques like bubble point testing or mercury intrusion porosimetry.
- Basis Weight and Thickness Measurement: These parameters are important for ensuring consistency between batches of filter paper.
- Chemical Compatibility Testing: This involves exposing the filter paper to various chemicals that it may come into contact with during use. The paper should not react with or be affected by these chemicals.
- Microscopic Analysis: Microscopic examination can be used to inspect the structure of the filter paper for any defects or irregularities.
- Wettability Testing: This involves assessing how readily the filter paper absorbs water, which is important for efficient filtration.
- Particle Retention Testing: This is especially important for filter papers used in critical applications, like air pollution monitoring. The filter paper’s ability to retain specific particle sizes should be tested.
- ISO Standards Compliance: Many manufacturers adhere to international standards set by organizations like the International Organization for Standardization (ISO).
Quantitative filter paper is a type of filter paper that is designed for gravimetric analysis and other quantitative laboratory techniques. It is characterized by its low ash content, which means that it leaves behind minimal residue when burned, making it suitable for accurate measurements.
Remember that the specific tests and criteria for quality detection may vary depending on the intended use and manufacturer’s specifications. It’s important to consult the manufacturer’s guidelines and any applicable industry standards when assessing the quality of quantitative filter paper.