MCE filters, or mixed cellulose ester filters are considered the standard when it comes to aerosol sampling. But there is a whole lot more to them than that. In fact, these filters can be used for different applications and have a number of benefits to consider. Once you know a bit more about MCE filters you’ll be able to choose the one that works best for your project.
What to Know About MCE
MCE filters are membrane filters that are made with what are considered ‘biologically inert mixtures.’ Specifically, the two primary ingredients used for this mixture are cellulose acetate and cellulose nitrate. Because of this, the membranes themselves have a low metal background, which makes them compatible with a range of different products including dilute bases, aromatic hydrocarbons, acids, and aliphatic hydrocarbons.
Where to Use MCE Filters
As mentioned, these filters are typically used for aerosol sampling and specifically in industrial hygiene applications. However, they can be used in other areas as well. In fact, they can be used for microbiological examinations related to pharmaceuticals, food and beverage, air monitoring, wastewater, and water.
In short, there are a multitude of different areas where these filters excel and can be used, however they are primarily focused in water-based purposes. This allows the filter to work at its best. It is not, however, rated to be used for protein extraction. The porousness of the filter means that it has too fast of a flow rate for this.
Benefits of MCE Filters
There are a number of additional benefits when it comes to using MCE filters. These include:
- Biologically inert
- Minimal interference for fiber counting
- Gridded filters for fiber counting
- Hydrophilic
- Autoclavable
- Low in metal background
- Compatible with dilute bases, aromatic hydrocarbons, acids, and aliphatic hydrocarbons
- High recovery rate
- Excellent flow rate
- Can be used for AAS, ICP, air monitoring and transmitted light microscopy
- Meet specifications under NIOSH and OSHA for monitoring fibers and airborne metals
- Complete dissolution and clearing
- Low artifact purity
- Standard digestion
- Used for study of nanoparticle morphology and elemental makeup
Biologically Inert
MCE membrane filters do not have any kind of response or interaction when they come into contact with biological tissue. This means they can be used in the body or related to the body without causing reactions.
Fiber Counting
MCE membrane filters have a pore structure that actually collapses if it is exposed to an acetone vapor. This allows for easier fiber counting.
Gridded Filters
The design of gridded filters allows for easier counting of fibers, which is especially good in counting asbestos fibers, as an example.
Hydrophilic
These filters are wetted by water and are actually required to be wet in order to work properly.
Autoclavable
MCE membrane filters can be sterilized with a moist heat under pressure.
Low Metal Background
These filters can be used with different types of acids, hydrocarbons, bases, etc. because they do not have large amounts of metal that could otherwise interact with these materials.
Compatible with dilute bases, aromatic hydrocarbons, acids, and aliphatic hydrocarbons
Because of the low metal background these filters are able to work well with different types of materials without causing an interaction.
Excellent flow rate
The flow rate for MCE filters is high, and can provide excellent permeability for water based solutions.
Can be used for AAS, ICP, air monitoring and transmitted light microscopy
Filters of this type can be used with a range of different scientific processes, including those with different types of light and radiation.
Meet specifications under NIOSH and OSHA for monitoring fibers and airborne metals
The SKC MCE membranes specifically meant these specifications for monitoring fibers and airborne metals.
Complete dissolution and clearing
When finished, MCE membranes allow for complete removal of the sample from the filter.
Used for study of nanoparticle morphology and elemental makeup
Because of the overall makeup of these filters they can be used for more miniscule factors and scientific purposes including nanoparticles.
MCE Syringe Filters vs. Membrane Filters
You will need to consider the differences between MCE syringe filters and membrane filters, which will offer you slightly different options and abilities when it comes to the project at hand. You want to be sure that you are using the right tools to ensure the right filtration process.
MCE syringe filters are inexpensive but still provide accurate and measurable results. They come in several different sizes and materials and also offer both sterile and non-sterile surfaces to ensure compatibility with a range of different projects. They have excellent performance and durability, but are used for single use only.
On the other hand, MCE membrane filters offer even more applications and more control over things like strength, flexibility, pore size distribution, and therefore consistency. These filters are excellent quality and provide you with the results you need for your services.
You can also find MCE membrane roll stock to give you more of what you need without the complication of purchasing large quantities. You can purchase a full roll at a discounted rate and also meet all of the specifications that you have through a custom purchase.
Selecting the Proper Filter Characteristics
When it comes to selecting a filter for any task there is a prescribed process involved which requires four simple steps. These steps can be done with a filter media selector and include:
- Deciding on the necessity of prefiltration for the application.
- Choosing a membrane filtration material based on qualities such as aqueous, non-polar, and protein.
- Selecting a diameter typically of <10ml, <100ml, or <250ml to determine the mm diameter of the filter.
- Ensuring the pore size, based on micron size of the column of >3um or <3um.
Be sure that you evaluate the chemical compatibility guide to determine materials that MCE is considered compatible with. The compatibility chart will help you to evaluate ways in which the filter can be used.
For more information on selecting the right filtration media for your needs, watch this short video.
Important Considerations when Using MCE Membrane
In the use of MCE membranes there are a number of factors that need to be closely evaluated and considered in order to ensure the best possible outcome for your application.
- Membrane filters require liquid. When filtering liquids the filter needs to be wet using sterile water. It is possible for disinfection to cause the membrane to dry, in which case new sterile water must be used.
- Membranes are only to be used for liquids including oils, air, and fruit juices. These membranes resist temperatures of 120 degrees as well as solvents, flammable substances, acids, alkali, and more.
- Microporous membranes are not rated for retentation below 0.025 microns.
- Natural pressure, pressurization, vacuum, and negative pressure should all be used to ensure bacteria and particles in the air do not pollute the filtrate during the vacuuming process.
- Liquid then enters into the filter should still allow air to escape to ensure adequate filtration speed.
- Filters should be soaked for approximately four hours and rinsed prior use.
By keeping track of each of these factors it is possible to ensure proper use of the membrane and also to ensure adequate filtration of the materials.
MCE Filters For Any Use
When it comes to using MCE filters for your application there are a number of considerations and important factors to consider, however there are ways to ensure you are working with the right material. Ensure that you follow the selection process above and you should be ready to go with your next project.