Glass fiber filters are made of 100 % borosilicate microfibers and are characterized above all by their inert behavior towards acids (with the exception of hydrofluoric acid), moderately concentrated alkalis and high temperatures. Glass fiber filters are fast filtering and have a high retention capacity of even the finest particles in the subµ range. Due to their high retention capacity, glass fiber filters can be used for larger volumes compared to paper filters, as the filtration speed decreases less with increasing particle load. Glass fibre filters from established manufacturers like Pall, Whatman, Sartorius, etc are available here.
Further informations about glass fibre filters you will find here.
As the Schleicher & Schuell brand is part of Whatman Cytiva, the following overview provides a comparison of the most common varieties:
Sartorius | Whatman | Schleicher & Schuell | Sartorius | Whatman | Schleicher & Schuell | |
---|---|---|---|---|---|---|
MGA | GF/A | GF 50 | MGF | GF/F | GF 55 | |
MGB | GF/B | GF 51 | MGF 550-HA | 934AH | n/a | |
MGC | GF/C | GF 52 | MK 360 | QM-A | n/a | |
MGD | GF/D | GF 53 |
Micro glass fiber filters offer high efficiency and particle retention combined with high air permeability. They are made of 100 % pure borosilicate glass fibers that are biologically inert and resistant to most solvents and reagents except hydrogen fluoride and highly concentrated alkaline solutions.
Glass fibre filters without binder are suitable for the filtration of buffer, reagent and protein solutions, as well as air and water monitoring. Glass fibre filters with binder however contain an additional binder, which can be hydrophobic or hydrophilic. They are often used for air and gas monitoring. Their chemical resistance corresponds to that of glass fibre filters without binder, but their thermal resistance is limited to temperatures of approx. 180°C during prolonged exposure. Both types of glass fiber filters can also be used as pre-filters for membrane filtration.
The table below provides an overview of common glass fibre filters and their fields of application:
Grade | Application |
---|---|
MGA | Highly efficient for general laboratory filtration, purification of buffer and reagent solutions, complies with many international standards for air and water pollution monitoring, food analysis, filtration of algae, bacterial cultures and proteins |
MGB | Filtration of dissolved solids in water, waste water analysis, membrane pre-filters, suitable for the filtration of large volumes |
MGC | Standard filters for wastewater and water treatment and monitoring, scintillation counting on the filter, cell collection, hydrocarbon analysis where cellulose fibres interfere |
MGD | All-purpose membrane pre-filter |
MGF | Better retention capacity for smaller particles than other glass fibre filters, purification of protein solutions, filtration of liquids before HPLC |
MG 550 HA | Temperature-resistant up to 550°C, recommended for determining the solids concentration in water (TSS/standard method 2540D) |
Glass fibre filters are also available as round filters for e.g. funnels, as sheets or as syringe filters.