Inline filters

Biotech Fluidics provide inline filters to protect sensitive equipment parts at a range of different conditions. We offer various types of inline filters for flow rates from a few microlitres up to several millilitres per minute. Some of these filters are biocompatible by offering a PEEK-based design with a metal-free flow path, whereas other are based on stainless-steel.

Note that although the design of the bodies for precolumn filters and inline filters look similar and both are used for HPLC applications, their intended use is rather different. Precolumn filters, by definition, are typically placed in a volume-sensitive area immediately preceding the HPLC column. These filters usually feature smaller thru-holes and smaller frit diameters to minimize effect on chromatographic peak shapes. In contrast, inline filters are placed where the internal volume is not as critical and where longer life and less fluid restriction is more important.

Several variants available:

  • Analytical inline filters
  • Analytical precolumn filters
  • Semi-prep inline filters
  • Inline MicroFilters
  • Mini MicroFilters
  • Precolumn MicroFilters

Analytical inline filters

Standard analytical inline filters

Our Inline Filters are specially engineered for inline filtration. It is specifically designed to help prevent particulate contamination from clogging sensitive equipment. It is ideally suited for placement along the flow path line between the pump and injection valve/autosampler. We offer a variety of porosities for your application.

  • For 1/16” OD tubing
  • For Standard HPLC (6,000 psi/414 bar)
  • Replacement frits available
  • Help prevent particulate contamination from clogging sensitive equipment
  • Ideally suited for placement along the flow path line between the pump and injection valve/autosampler

Biocompatible analytical inline filters

Our A-430 and A-431 Inline Filters consist of a stainless steel body and two PEEK end fittings. Maximum recommended flow rate is 25 mL/min for the A-430 Filter and 10 mL/min for the A-431 Filter. And, you get the added benefit of biocompatibility since all wetted surfaces are PEEK. When you need to replace the frit, simply dispose of the end fitting that contains the frit and replace it with a new one.

  • 0.5 µm and 2 µm versions available
  • Features 100% PEEK flow path

Prod. No.*DescriptionPorosityFor Tubing SizePortIncludesSwept VolumePressure Rating
A-313Inline Filter Assembly20 µm1/16” OD10-32 ConedA-22412.3 µL6,000 psi (414 bar)
A-314Inline Filter Assembly2 µm1/16” OD10-32 ConedA-1004 µL6,000 psi (414 bar)
A-100Replacement Frit, Stainless Steel, 1 ea2 µm---1.4 µL-
A-224Replacement Frit, Stainless Steel, 1 ea20 µm---9.7 µL-
A-430Biocompatible Inline Filter Assembly2 µm1/16” OD10-32 ConedA-4297.1 µL6,000 psi (414 bar)
A-431Biocompatible Inline Filter Assembly0.5 µm1/16” OD10-32 ConedA-4285.9 µL6,000 psi (414 bar)
A-428PEEK Filter End Fittings, Black PEEK body0.5 µm---5.7 µL-
A-429PEEK Filter End Fittings, Black PEEK body2 µm---6.9 µL-

Analytical precolumn filters

Standard precolumn filters

Our economical Precolumn Filters offer secure protection for analytical columns in HPLC. We offer traditional versions that can successfully connect tubing on both sides and our direct-connect versions attach to the inlet port of most standard columns. All versions feature a 10-32 coned ports for 1/16” OD tubing. These are designed to protect columns by filtering out particulate matter originating from the sample or from rotor seal wear.

  • Economical protection for larger columns and injections
  • Traditional versions connect tubing on both sides
  • Direct-connect versions attach to the inlet port of most standard columns
  • All versions feature 10-32 coned ports for 1/16” OD tubing

Biocompatible precolumn filters

Biocompatible Precolumn Filters have 0.020” (0.50 mm) diameter thru-holes and 8° distribution cones for minimal band spreading and mixing. The bodies of these filters are manufactured from biocompatible PEEK polymer and are pressure rated to 5,000 psi (345 bar). These filters are designed for use with 1/16” OD tubing, which can be connected to these filters using standard Fingertight fittings.

  • Pre-assembled with either 0.5 µm or 2 µm porosity frits
  • Great column protection
  • Feature PEEK bodies and PCTFE-surrounded PEEK frits

Prod. No.*DescriptionPorosityFor Tubing SizePortIncludesSwept VolumePressure Rating
A-315Precolumn Filter Assembly2 µm1/16” OD10-32 ConedA-1011.4 µL6,000 psi (414 bar)
A-318Precolumn Filter Assembly0.5 µm1/16” OD10-32 ConedA-1020.84 µL6,000 psi (414 bar)
A-101Replacement Frit, Stainless Steel2 µm---0.74 µL-
A-102Replacement Frit, Stainless Steel0.5 µm---0.61 µL-
A-355Biocompatible Precolumn Filter Assembly2 µm1/16” OD10-32 ConedA-7001.4 µL5,000 psi (345 bar)
A-356Biocompatible Precolumn Filter Assembly0.5 µm1/16” OD10-32 ConedA-7011.3 µL5,000 psi (345 bar)
A-700Replacement Frit, PEEK Polymer2 µm---0.74 µL-
A-701Replacement Frit, PEEK Polymer0.5 µm---0.61 µL -

Semi-preparative inline filters

Standard semi-prep inline filters

Our Semi-Prep Filter Assemblies are meticulously designed for high flow applications. They are SFC and HPLC compatible and adds only 50 psi (3 bar) additional back pressure. They have a porosity of 10 µm and includes a stainless steel frit (A-331). Alternative filter porosities are available.

  • Designed for high-flow applications
  • Economical protection for larger columns and injections
  • SFC and HPLC compatible

Biocompatible semi-prep inline filters

Biocompatible Semi-Prep Filters consist of a stainless steel body, two PEEK end fittings, and a separate PEEK frit. These filters are ideal for many higher flow analytical, semi-prep and preparative applications. Best of all, if the filter becomes clogged, simply unscrew the assembly, remove the frit and replace it. The frits are interchangeable.

  • Versions for 1/16”, 1/8”, & 3/16” OD tubing
  • 100% PEEK flow path

Prod. No.*DescriptionPorosityFor Tubing SizePortIncludesSwept VolumePressure Rating
A-330Standard Semi-Prep Filter Assembly10 µm1/16" OD10-32 ConedA-331223 µL7,500 psi (517 bar)
A-360Standard Semi-Prep Filter Assembly10 µm1/16", 1/8", or 3/16" OD5/16-24 Flat BottomA-331235 µL3,500 psi (207 bar)
A-331Stainless Steel Frits, Natural ETFE ring10 µm---142 µL-
A-332Stainless Steel Frits, Natural ETFE ring2 µm---122 µL-
A-337Stainless Steel Frits, Natural ETFE ring20 µm---152 µL-
1020-05Iso-Prep 21.2 mm Filter Holder0.5 µm1/16" OD10-32 Coned7031-05203 µL8,000 psi (552 bar)
1020-20Iso-Prep 21.2 mm Filter Holder2 µm1/16" OD10-32 Coned7031-20196 µL8,000 psi (552 bar)
7031-05Iso-Prep 21.2 mm Replacement Filter 0.5 µm---122 µL8,000 psi (552 bar)
7031-20Iso-Prep 21.2 mm Replacement Filter2 µm---115 µL8,000 psi (552 bar)
A-410Biocompatible Semi-Prep Filter Assembly2 µm1/16" OD10-32 ConedOC-80289 µL6,000 psi (414 bar)
A-411Biocompatible Semi-Prep Filter Assembly10 µm1/16" OD10-32 ConedOC-803103 µL6,000 psi (414 bar)
A-510Biocompatible Semi-Prep Filter Assembly5 µm1/16", 1/8", or 3/16" OD5/16-24 Flat BottomOC-80589 µL500 psi (34 bar)
OC-802PEEK Frit, Green PCTFE ring2 µm---46 µL-
OC-803PEEK Frit, Natural PCTFE ring10 µm---57 µL-
OC-805PEEK Frit, Natural PCTFE ring5 µm---50 µL-

Inline MicroFilters

Our Inline MicroFilters protect your column from particles originating in the mobile phase or sample, or from pump seal and sample injection valve wear. These filters have a 0.006” (150 µm) thru-hole. Choose the M-520 with a 0.5 µm 100% PEEK frit to connect to capillary tubing using the MicroTight tubing sleeves (page 52). You may also directly connect 1/32” OD tubing using the M-525 which contains a 0.5 µm PEEK frit.

  • 100% biocompatible PEEK polymer option available
  • Miniscule 240 nL void volume
  • Two versions: direct connect 1/32” OD tubing or use MicroTight® tubing sleeves for 70–520 µm OD capillary tubing

Prod. No.*DescriptionPorosityFor Tubing SizePortIncludesSwept VolumePressure Rating
M-520Inline MicroFilter Assembly, PEEK Frit0.5 µmMicroTight Tubing Sleeve6-32 ConedM-120 (5), F-125 (2)240 nL4,000 psi (276 bar)
M-525Inline MicroFilter Assembly, PEEK Frit0.5 µm1/32” OD6-32 ConedM-140 (5), F-126S (2)240 nL4,000 psi (276 bar)
M-120End-Fittings, Black, with PEEK Frit0.5 µmMicroTight Tubing Sleeve6-32 Coned-216 nL-
M-140End-Fittings, Natural, with PEEK Frit0.5 µm1/32” OD6-32 Coned-216 nL-

Mini MicroFilters

Our Mini MicroFilter Assemblies filter effectively with internal volumes low enough to ensure reliable chromatographic results — even at nanoliter per minute flow rates! Internal volumes of these encapsulated filters are as low as 85 nL with the micro-screen and 10 nL to 22 nL with the frit disc option.

  • Total volume as low as 10 nL
  • Conductive version for CEC and mass spectrometry applications

Prod. No.*DescriptionPorosityFrit TypeFor use withIncludesSwept VolumePressure Rating
M-547Mini MicroFilter Assembly1 µmSST Frit1/32” (790 µm) OD tubingM-133 (5), F-112 (2), P-416 (2)22 nL4,000 psi (276 bar)
M-121Filter Capsule, PEEK, 2 ea1 µmSST ScreenM-530 and M-531-85 nL-
M-125NanoFilter Capsule, PEEK, 2 ea1 µmSST FritM-537 and M-538-10 nL-
M-131Filter Capsule, PEEK, 2 ea1 µmSST ScreenM-543-85 nL-
M-133NanoFilter Capsule, PEEK, 2 ea1 µmSST FritM-547 and M-548-10 nL-
M-128Conductive NanoFilter Capsule, SST/PEEK, 2 ea1 µmSST FritM-534-10 nL-

Precolumn MicroFilters

The Precolumn MicroFilters directly connect into your microbore or analytical column. Total theoretical void volume is only 0.5 µL (includes frit volume) and the PEEK tubing used in the assembly of these units has a 0.005” (125 µm) ID, virtually eliminating any mixing of the sample with the mobile phase.

  • Direct connects to columns with 10-32 threads
  • Total void volume of 0.5 µL
  • Two versions: direct connect 1/16” OD tubing or use MicroTight® tubing sleeves for 70–520 µm OD capillary tubing

Prod. No.*DescriptionPorosityFor Tubing SizePortIncludesSwept VolumePressure Rating
M-500Precolumn MicroFilter Assembly, SST Frit0.5 µmMicroTight Tubing Sleeve10-32 ConedC-425 (5), F-172, P-4160.5 µL4,000 psi (276 bar)
M-510Precolumn MicroFilter Assembly, PEEK Frit0.5 µmMicroTight Tubing Sleeve10-32 ConedA-735 (5), F-172, P-4160.5 µL4,000 psi (276 bar)
M-550Precolumn MicroFilter Assembly, SST Frit0.5 µm1/16" OD10-32 ConedC-425 (5), F-172, P-4160.5 µL4,000 psi (276 bar)
M-560Precolumn MicroFilter Assembly, PEEK Frit0.5 µm1/16" OD10-32 ConedA-735 (5), F-172, P-4160.5 µL4,000 psi (276 bar)
A-735PEEK Frits, 0.045” x 0.031” x 0.192”0.5 µm---216 nL-
C-420SST Frits, 0.038” x 0.028” x 0.192”2 µm---101 nL-
C-425SST Frits, 0.038” x 0.028” x 0.192”0.5 µm---101 nL-

Any questions?

If you have any inquiries about our products and services, we’re here to help.

Phone: +46 300 56 91 80
Email: info@biotechfluidics.com