Are AQ brand nylon syringe filters compatible with DMSO?

Yes, the MicroSolv AQ™ brand of syringe filters for dissolution testing and HPLC are made with a polypropylene housing which is DMSO compatible. Our nylon membranes, both 0.45um and 0.22um are fully compatible with solutions containing DMSO. Nylon is also compatible with esters, alcohols, weak acids and bases. AQ Brand of syringe filters for HPLC and Dissolution […]

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Are the MicroSolv AQ Brand syringe filters sterile?

No, but on special order we can supply our syringe filters in individual blister packs and can be sterilized. Depending on the membrane, the sterilization could be autoclaving or radiation. .  Syringe Filters Ordering Information Attachments MicroSolvFiltersEquivalency.pdf  26.9 Kb   Download File

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Are the MicroSolv AQ™ brand syringe filters bi-directional in their flow?

Yes, all the filters are bidirectional except PTFE and those that have pre-filters for aqueous solutions. Although in a syringe filter format the flow in two directions may not be equivalent because of the filter design. In organic solvent all the filters are bidirectional. Syringe Filters Information Attachments MicroSolvFiltersEquivalency.pdf  26.9 Kb Download File

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Avoid Loss in Concentration of Heparin with HPLC when Using Syringe Filters.

Heparin has strongly Acidic Sulfonate groups (negatively charged) that will bind with Nylon Filter membranes. PTFE is not suitable because of its hydrophobicity and passes Water through it is is not possible. The most Appropriate Membrane type to use when Filtering Heparin-containing samples is AQ™ Brand Regenerated Cellulose (RC) syringe filter. AQ Brand Syringe Filter […]

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Can I autoclave the MicroSolv AQ Brand 25mm PTFE syringe filters?

Yes, under conditions of 121 C for a maximum of 15minutes, the PTFE filters can be autoclaved. Maximum operating temperature (continuous) we suggest that you do not exceed 80 C to maintain optimum performance. Syringe Filters Ordering Information Attachments MicroSolvFiltersEquivalency.pdf   26.9 Kb   Download File

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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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Can I sterilize my sample by using a syringe filter?

When you use a 0.2 µm filter you remove any particle that is larger than 0.2 µm. This includes bacteria as well as most viruses and spores. However, it is important to note that when you remove these interferences, once they pass the membrane and enter the filter device, your solution is not really sterile any longer, […]

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Do Nylon syringe filters have a neutral membrane or do they carry a charge?

All nylon membranes carry some positive charge, some much more than others. The AQ™ brand of nylon syringe filters are manufactured with membranes that have highly reduced charge. This brings a value to dissolution testing or HPLC filtering as the excess positive charge on membranes will adsorb negatively charged analytes and will change the accuracy of your results […]

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I use normal phase HPLC, which syringe filter do you recommend?

PTFE is the best for use with non polar, organic solvents required for normal phase chromatography. You should also consider using Aqueous Normal Phase chromatography if possible. See link below. AQ Syringe Filter Ordering Information Attachments MicroSolvFiltersEquivalency.pdf   26.9 Kb   Download File

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If I use one syringe filter for many samples will I get sample carry over?

You will most likely get some kind of carry over. It is not recommended to use one filter for more than one sample. Reusing the same syringe filters for multiple samples is never recommended due to carry over problems. Click HERE for AQ Syringe Filter Ordering Information Attachments MicroSolvFiltersEquivalency.pdf   26.9 Kb   Download File

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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 from a Syringe Filter? – FAQ

Extractables found in the Filtrate of a Syringe Filter (or other devices) is any chemical / foreign body present in your sample after filtering that wasn’t there before. This would indicate the Filter as the source and usually it’s the Filter Membrane. Occasionally, Extractables from the polypropylene housing can occur depending on the solvent being […]

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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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White Paper: Equivalency Study of Syringe Filters, in-situ.

An unbiased study was conducted by a Pharmaceutical Company that compared market leading brands of Syringe Filters in situ to MicroSolv’s AQ™ Brand of Syringe Filters. The results were that AQ™ (Advanced Quality) Filters were not only the Quality Leader but can be purchased at quite a substantial cost savings. These Syringe Filters were designed […]

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