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 […]
Category: Syringe Filters FAQ
Are nylon filters compatible with chloroform?
All nylon filters are not recommended for use with halogenated solvents such as chloroform or with strong acids (1N and stronger). For these liquids, you should consider using PTFE filters. View filtration products
Are the AQ Nylon Filters suitable for sterile filtration?
The AQ™ Syringe filters are not designed for sterile filtration. Their intended function is only to remove particulate matter from a sample to be injected into an HPLC instrument. AQ Brand Syringe Filters Ordering Information
Are the MicroSolv AQ Brand of syringe filters membranes supported by extra membranes in the plastic housing device?
The PTFE (Teflon) syringe filter membranes are backed with a polypropylene support all the others including Nylon, Regenerated Cellulose, Cellulose Acetate and PVDF are not. Syringe Filters Ordering Information Attachments MicroSolvFiltersEquivalency.pdf 26.9 Kb Download File
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
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
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 […]
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
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 […]
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, […]
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 […]
I See Extra Peaks in my Data and Sometimes I am not Using the Same Filter. Suggestions? FAQ
Yes, “Best Practices” for using any Syringe Filter is to dispose of the first few milliliters that comes through the Filter. If there are any Extractables or if there is going to be any adsorption to the Membrane, it will usually happen in the first few milliliters. This is called bringing the filter to a […]
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
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
Is the MicroSolv AQ Nylon Filter Compatible with Formamide? – FAQ
Yes, our MicroSolv AQ™ Nylon syringe filters are compatible with Formamide. Formamide, Dimethylformamide, and Acetamide, are all compatible with our MicroSolv AQ™ Nylon filters. Acetamide: Dimethylformamide: Formamide: AQ Syringe Filter Product Page
Spurious Peaks from Nylon Syringe Filters with DI Water using Electrochemical Detection can be avoided.
When using Electrochemical Detection, spurious Peaks in your Chromatogram may be observed if a Nylon Syringe Filter is used with a DI Water solvent. The anionic peaks are most likely Nitrate Extractable and therefore we recommend using Polyester Sulfone (PES) Syringe Filters instead. This membrane type is suited to situations when you want to avoid nitrate […]
What are the Differences between Nylon and PTFE Filters for my Filtration Application? FAQ
There is a bit of a misconception in the field regarding PTFE v. Nylon Membranes for Filtration using Syringe Filter Devices and which Membrane can be used with different solutions and or solvents. PTFE as a Membrane for Syringe Filters is considered to be more “chemically resistant” and Nylon to be the most “extractable free” […]
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 […]
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 […]
What is the Difference Between a Luer Lock and a Luer Slip Connector?
When using a device such as a Syringe Filter and a Chrom Syringe which both have Luer Slip Connectors on them, the Syringe Filter device will simply slide onto the tip of the Syringe. If it is applied properly (fully placing the device onto the tip of the syringe and a quarter turn while applying […]
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 […]
What is the maximum sample volume for a 25mm AQ syringe filter?
You can use up to 100ml in a single 25mm syringe filter is you are using an aqueous solvent and your sample is not cloudy. However, the best way to determine if the filter should be replaced is when you get either a very fast drop in back pressure or a constant rise in back […]
What product traceability does MicroSolv provide for its AQ Brand syringe filters? Do you retain samples from each lot?
All MicroSolv syringe filters have lot numbers which can be followed to complete traceability to the raw materials used in manufacturing the filters. We have a mandatory 3 year archive time of samples and lot analysis. Syringe Filters Ordering Information Attachments MicroSolvFiltersEquivalency.pdf 26.9 Kb Download File
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 […]
Which solvents should I avoid with syringe filters that have a Nylon membrane?
Aldehydes and strong acids such as hydrochloric and nitric should be avoided. Syringe Filters Information Attachments MicroSolvFiltersEquivalency.pdf 26.9 Kb Download File
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 […]
Why is filtering of water samples very slow when using PTFE membrane filters?
PTFE is very hydrophobic and therefore not well-suited to aqueous-based samples. Due to the polarity difference, it will be difficult to filter. Nylon is more hydrophilic and should be used for water-based samples instead. Membrane Filter Product Page
Will I Protect my HPLC Columns from Samples that Permanently Adsorb to them by using a Syringe Filter? FAQ
No, some lab people get confused on the purpose of Syringe Filters. They are not Chemical Filters, only Particulate Filters and only remove un-dissolved Particles from your Samples. If anything is dissolved in your Solvent, and once the Filter is at a Steady State, it will not Adsorb anything. It will only Exclude Particles that […]
Will I see any differences in my HPLC chromatography if I use your AQ syringe filters?
If you use proper techniques, you should not see any differences in your chromatography, CE or UV testing. Syringe filters only protect your equipment and columns and never participate in separations or SPE. Syringe Filters Information Attachments MicroSolvFiltersEquivalency.pdf 26.9 Kb Download File