COBETTER100 Pack Syringe Filter Nylon Lab Filters 0.45μm Pore Size 25mm Diameter Hydrophilic Filtration Non-sterile White

Would be great if they had more stock - I would like to order a larger quantity - 1,000s not 100s.

These filters seem to be good. I am not familiar with this company but the Cobetter Filtration website describes a large manufacturing company headquartered in Hangzhou China that was founded in 2003 and now has subsidiaries located world-wide. They apparently have extensive experience in membrane filtration.Syringe filters are described on the Cobetter site including 25 mm Unichro Syringe Filters, and a 0.22 micron Nylon filter seems to be the same product although it has a different Cat No (SFM25NY0022) rather than the number for this Amazon product which is SFUNY-2025. I normally use 0.45 μ filters but the flow through these filters with both aqueous buffers and with methanol was quite good, and they are substantially less expensive than the well-known brands such as Whatman, Corning and Millex. In fact, both these Cobetter filters and the container they come in look very similar to Foxx EZFlow filters which are about 4 times more expensive.I think these should work well for filtering HPLC solvents. The housing is well sealed and strong. The luer inlet is a little shorter and the outlet a little longer than Whatman filters I have used, but no issues there. The inlet is unusual in that it seems slightly threaded rather than just having tabs, but it works the same and locks onto a syringe well.Extractables are always a concern with a UV detector so I took a quick look at that. After passing 3 mL of water through 2 filters, the absorbance at 280 nm was 0 relative to a blank, and averaged a low 0.007 (0.005 and 0.008) at 262 nm which is my primary wavelength of interest. I also passed 1.5 mL of methanol through 2 more filters and dried the filtered solvent along with 2 unfiltered blanks. After recovering the residues in water, both blanks read 0 and the filtered samples were very similar at about 0.036 OD at 280 nm and 0.074 at 262. Of course these were direct measurements so I don’t know if any contaminant would even co-elute with peaks of interest. Anyway, no problem for mobile phase filtration.Overall, these filters were fine and are substantially less expensive than the established brands. However, whether they will prove reliable and consistent over time will need to be determined. The filters are not validated with ISO certs for example so it is probably worthwhile to check each different lot number before use. At this point though, they seem to be good filters at a good price.

I built a home-made photometer to measure beer color according to the SRM method requirements. This procedure involves shining a blue light through a 1-cm transparent glass or plastic cell containing the beer. The loss of light within the cell is measured and this information is used to calculate the SRM value. This information is important for brewing QC and for the subsequent judging of beers.One potential problem with this method is that if there is suspended solid material in the beer (yeast, proteins, etc.) the results will be compromised because of light scattering and light absorption by the suspended particles. In such situations, the solution is to filter the beer to remove these particles. These 0.2µm-pore nylon filters from Cobetter look as if they would be ideal for filtering beer for this purpose.The product comprised a small plastic tub containing 100 of these filters. These filters are hydrophilic and so are better suited than hydrophobic filters to filter aqueous-based samples like beer. They are offered in two sizes: 13mm and 25mm. I only need about 3mL of filtered beer to take a color measurement, so the 13mm size looked adequate for my needs. Perhaps if the beer was murky and contained a lot of sediment, the bigger size might be better. These filters are not sterile and I felt that there was no need to pay extra for this feature for this application. The filters have a Luer-Lok type inlet and so will only work with syringes with this fitting. The Luer-Lok connection is important as it will stop the filter popping off the syringe when high pressure is applied as the syringe plunger is depressed. Another side-benefit of filtering beer is that the carbonation is largely eliminated and so problems with foaming and bubbles forming in the light cell are much reduced.I tested these filters with a generic brand 3-mL plastic syringe on a variety of beers. Most hazy beers filtered easily with moderate pressure applied and gave much clearer samples for subsequent color measurement. The exception was New England IPAs which were real pigs and required a lot more pressure to filter – however, the filters still did a good job.In summary, these filters were very effective at removing suspended solid material from beer to enable better color measurements. I’m sure that they could be used for other purposes, too, with similar success.

I use these for mytCheck cannabis testing machine, for filtering my solution before testing. I have ‘washed’ the filters with alcohol after use and then tested against new and did not see a discrepancy at my level of testing.

syringe filters. They do exactly what theyre supposed to. Would buy more when I need them.

My son is really interested in his microscope and we wanted to try these out to see what we could separate from various water sources. It worked so well there wasn't much left in there. Maybe we need a stronger microscope? I know this isn't a professional use but I can tell you we had a blast experimenting and that's what science is all about!