Frequently Asked Questions

A. Syringe filters

What are syringe filters?


Also known as wheel filters because of their wheel-like shapes, syringe filters are attached to the end of a syringe and are frequently used for removing particles in samples. Removal of particles in the sample preparation step is very imporant for high performance liquid chromatography (HPLC) as large particles can clog or damage the column and also cause interference in the analysis results. For ultra performance liquid chromatography (UPLC), filtration of the sample prior to analysis is especially important due to their much smaller particle size columns. Syringe filters could be produced as sterile or non-sterile for use in different industries. They may also be used for general purpose filtration, especially for smaller volumes where sample losses from larger filters are significant. Syringe filters are also used for the filtration of gases and for the removal of bacteria from a sample.




What size syringe filter do I need?


Syringe filters are sized according to their inner diameter. Based on the volume of the samples, you can choose the appropriate sizes from the following;




Which syringe filter should I use?


With all the different types of membranes, it is best to choose the right one for the job. We recommend that you use the following table as a guide.





D. Quality Control

What is the integrity testing method?


Intergrity testing sterilizing filter is a fundamental requirement of critical process filtration applications in the pharmaceutical industry. There are two classifications of integrity testing, destructive and non-destructive. Finetech's practice is to perform destructive testing as a lot release criteria on samples from each manufacturing lot of all fabricated sterilizing-grade filter products, and non-destructive testing on each sterilizing-grade filter prior to sale to insure its integrity. Destructive challenge testing is the best way to determine a sterilizing filter's ability to retain bacteria. While Non-destructive testing may be done on filters before and after use. Integrity testing sterilizing filters before use monitors filter integrity prior to batch processing, preventing use of a non-integral filter. There are three types of non-destructive testing which are the bubble point test, the diffusion test, and the water flow integrity test for hydrophobic filters.




What is bubble point test?


A bubble point test is a test designed to determine the pressure at which a continuous stream of bubbles is initially seen downstream of a wetted filter under gas pressure. To perform a bubble point test, gas is applied to one side of a wetterd filter, with the tubing downstream of the filter submerged in a bucket of water. The filter must be wetted uniformly such that water fills all the voids within the filter media. When gas pressure is applied to one side of the membrane, the test gas will dissolve into the water, to an extent determined by the solubility of the gas in water. Downstream of the filter, the pressure is lower. Therefore the gas in the water on the downstream side is driven out of solution. As the applied upstream gas pressure is increased, the diffusive flow downstream increases proportionally. At some point, the pressure becomes great enough to expel the water from one or more passageways establishing a path for the bulk flow of air. As the result, a steady stream of bubbles should be seen exiting the submerged tubing. The pressure at which this steady stream is noticed is refered to as the bubble point.





D. Quality Control

What is the integrity testing method?


Intergrity testing sterilizing filter is a fundamental requirement of critical process filtration applications in the pharmaceutical industry. There are two classifications of integrity testing, destructive and non-destructive. Finetech's practice is to perform destructive testing as a lot release criteria on samples from each manufacturing lot of all fabricated sterilizing-grade filter products, and non-destructive testing on each sterilizing-grade filter prior to sale to insure its integrity. Destructive challenge testing is the best way to determine a sterilizing filter's ability to retain bacteria. While Non-destructive testing may be done on filters before and after use. Integrity testing sterilizing filters before use monitors filter integrity prior to batch processing, preventing use of a non-integral filter. There are three types of non-destructive testing which are the bubble point test, the diffusion test, and the water flow integrity test for hydrophobic filters.




What is bubble point test?


A bubble point test is a test designed to determine the pressure at which a continuous stream of bubbles is initially seen downstream of a wetted filter under gas pressure. To perform a bubble point test, gas is applied to one side of a wetterd filter, with the tubing downstream of the filter submerged in a bucket of water. The filter must be wetted uniformly such that water fills all the voids within the filter media. When gas pressure is applied to one side of the membrane, the test gas will dissolve into the water, to an extent determined by the solubility of the gas in water. Downstream of the filter, the pressure is lower. Therefore the gas in the water on the downstream side is driven out of solution. As the applied upstream gas pressure is increased, the diffusive flow downstream increases proportionally. At some point, the pressure becomes great enough to expel the water from one or more passageways establishing a path for the bulk flow of air. As the result, a steady stream of bubbles should be seen exiting the submerged tubing. The pressure at which this steady stream is noticed is refered to as the bubble point.





D. Quality Control

What is the integrity testing method?


Intergrity testing sterilizing filter is a fundamental requirement of critical process filtration applications in the pharmaceutical industry. There are two classifications of integrity testing, destructive and non-destructive. Finetech's practice is to perform destructive testing as a lot release criteria on samples from each manufacturing lot of all fabricated sterilizing-grade filter products, and non-destructive testing on each sterilizing-grade filter prior to sale to insure its integrity. Destructive challenge testing is the best way to determine a sterilizing filter's ability to retain bacteria. While Non-destructive testing may be done on filters before and after use. Integrity testing sterilizing filters before use monitors filter integrity prior to batch processing, preventing use of a non-integral filter. There are three types of non-destructive testing which are the bubble point test, the diffusion test, and the water flow integrity test for hydrophobic filters.




What is bubble point test?


A bubble point test is a test designed to determine the pressure at which a continuous stream of bubbles is initially seen downstream of a wetted filter under gas pressure. To perform a bubble point test, gas is applied to one side of a wetterd filter, with the tubing downstream of the filter submerged in a bucket of water. The filter must be wetted uniformly such that water fills all the voids within the filter media. When gas pressure is applied to one side of the membrane, the test gas will dissolve into the water, to an extent determined by the solubility of the gas in water. Downstream of the filter, the pressure is lower. Therefore the gas in the water on the downstream side is driven out of solution. As the applied upstream gas pressure is increased, the diffusive flow downstream increases proportionally. At some point, the pressure becomes great enough to expel the water from one or more passageways establishing a path for the bulk flow of air. As the result, a steady stream of bubbles should be seen exiting the submerged tubing. The pressure at which this steady stream is noticed is refered to as the bubble point.





E. Vials

What is the use of Scintillation Vials?


The main purpose is for an analytical technique, liquid scintillation counting, which detects the activity of a radioactive material in a sample. Before use in a liquid scintillation counter instrument, first, the sample is disolved or mixed into a mixture of a suitable solvent, a surfactant, and a scintillator.




What is the difference between Soda Lime and Borosilicate Glass?


Vials can be made with two types of materials, soda lime or borosilicate glass. Soda lime glass is the most commonly used glass in the world. It is composed of silicon dioxide (SiO2), sodium oxide (soda), and calcium oxide (lime). Borosilicate glass was developed to be physically and chemically stronger than soda lime glass. This type is used in laboratories when soda lime glass would not be able to handle the rough treatment of daily lab use. -Borosilicate glass if more durable and is able to handle drops better than soda lime glass -Borosilicate glass much lower coefficient of thermal expansion, so it can handle changes in temperature without shattering. -Borosilicate glass is more resistant to chemical attacks such as from acids. Soda lime glass would be more susceptible and would cause substances to leach from the glass into the sample.





F. Other

What are transducer protectors?


Transducer protectors are used in hemodialysis blood lines to keep the blood side of the circuit separated from the machine side and to prevent contamination of the machine by the blood flowing through the circuit. This contamination could be very dangerous and can lead to patient cross contamination with hepatitis B or other viruses. Transducer protectors let air pass while preventing the blood from passing through. TP's incorporate bacterial retentive membrane (0.2µm).
Features:
1. Hydrophobic membrane with 0.2 micron pore size.
2. Prevents contamination of the internal pressure monitoring lines.
3. Antibacterial hydrophobic air filter with female luer lock/male luer lock
4. Custom printed blister packaging available
5. Connects blood tubing to the dialysis machine.
6. Protective hydrophobic barrier allows only sterile air to pass through, protecting patients and equipment from cross-contamination
7. Prevents blood and dialyzing fluids from damaging sensitive transducer monitoring devices.




What is High Performance Liquid Chromatography (HPLC)?


High Performance Liquid Chromatography (HPLC) is a form of column chromatography that pumps a sample mixture or analyze in a solvent (known as the mobile phase) at high pressure through a column with chromatographic packing material (stationary phase). HPLC has the ability to separate, and identify compounds that are present in any sample that can be dissolved in a liquid in trace concentrations as low as parts per trillion. High performance liquid chromatography is now one of the most powerful tools in analytical chemistry. It has the ability to separate, identify, and quantitate the compounds that are presented in any sample that can be dissolved in a liquid. Because of this versatility, HPLC is used in a variety of industrial and scientific applications, such as pharmaceutical, environmental, forensics, and chemicals.




What is the function of air vent filter?


For the safety of the workers and your equipment, always use a vent filter. These devices act as barriers on air lines. They contain hydrophobic media, which prevent the entry of water and aerosols into sensitive equipment and also protect the lab environment from aerosolized pathogens. Vent filters can also enable air to enter and exit vessels such as bioreactors, while maintaining the sterility of the interior environment.




What kind of filter holders are there?


Filter holders are typically either in-line or open-face in design. In-line filter holders have a variety of inlet and outlet connections, and are used in closed filtration systems with either a pressure or vacuum source. In-line filters are ideal for measurement of feed water contamination. They are easy to open and close, and provide a positive, leak-proof seal. Upstream vents, available on some filter holders, allow for the release of trapped gas during liquid filtration. Open-face holders are typically used to take industrial hygiene samples. These holders are easily attached to personal sampling pumps via tubing, with an open inlet surface for impaction of airborne contamination.





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Since 1999, Finetech is the leading Taiwanese manufacturer of syringe filters and offers a wide range of products for environmental, pharmaceutical, life science, and other laboratories.