Can I make a PTFE Syringe Filter More Hydrophilic? – FAQ

Yes, if you are wiling to introduce Methanol into your Method. For a 25mm syringe filter device; if you use 15-20mls of Methanol as a blank Filtrate, the Membrane will give you less back pressure after that for Aqueous samples. This “conversion” is due to “wetting” the Membrane with Methanol allowing more Aqueous Solvents to […]

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Filtering Proteins, which Membrane to Use.

Filters should not remove Proteins or any other dissolved Compounds from a solution. Proper filters have one purpose and that is to remove un-Dissolved particles no matter what they are. Some Filters, depending on the Membrane type and specifications, will adsorb Compounds such as Proteins to the Membrane but if the Solutions is Analyte abundant, […]

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What is a “Steady State” for Surfaces like Syringe Filters? FAQ

A Filter could have charged sites on it or a small amount of Extractables. Most manufacturers, including MicroSolv, produce Filters with the lowest Extractables possible. If these Extractables are soluble in the Solvent you are using, you should see them only in the first few milliliters. This aliquot should be discarded. If your Filter has […]

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What is an Extractable that comes from Syringe Filters? FAQ

An Extractable from a Syringe Filter or any device for that matter, is any Chemical that is present in your Sample after Filtering that was not there before and the source is the Filter. These Extractables can be from the material itself such as threads or can be from the manufacturing process. No matter the […]

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What is the difference between AQ™ brand and low cost syringe filter brands?

AQ™ syringe filters are made to a higher standard of quality such as extractables, adsorption, flow design and have a 3 piece leak proof plastic device. AQ™  filters are supplied with CofA for HPLC and Dissolution testing. They cost more but bring a “Consistency Insurance”. These filters have bright colored rings for ease of identification. For […]

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Which Filter Membrane is best for Aqueous Buffers? FAQ

The “Best Membrane” is a difficult Question to answer as it depends on your Sample that you are Filtering and the Solvent is it dissolved in. For most HPLC and Dissolution testing, Hydrophilic Nylon Membranes are generally used because they are durable, compatible with most Aqueous Solvents including Water and have the lowest Extractables with […]

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Why is Nylon called Nylon?

According to the “Answers Corporation” website, nylon was developed at both New York and London, simultaneously. However, it has also been stated that the letters “nyl” were arbitrary and the “on” was copied from the suffixes of other fibers such as cotton and Rayon. A later publication by DuPont (Context, vol. 7, no. 2, 1978) […]

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