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CHROMTECH :  Specialists in Chromatography
- Fluid Transfer Products : & FOR !All Your Laboratory Needs
- Importers & Distributors in AUSTRALIA

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more Filtration Hints 2016

Filtration Accessories
 Filtration Hints

Vac-u-Fill Bottles PDF
VacuCap fast Filtration(PALL)

Liquid Dispensers
DoibleCheckValve Dispenser Syringe
Syringe Pump

Hand Vacuum Pump

Selection of Filter Media : by size
Flow propl to (Diam) sqrd

0.45um : 0.22um 
1.00 : 0.25 x speed

Syringe Filter : max Pressure 72psi (PP body )

Membrane Filter

Pre Filter : protects main filter from blocking extends lifetime and can improve speed

use coarser Glass Fibre

some have Class Fibre

on top of main filter

Relative speed based on
-   Surface Area of  Pore Size um

13 : 25 : 33mm;(50mm 90mm
0.27:1.0:1.75:4.0, 1.3 x speed

at same Pore Size um
& samemembrane material


-   Liquid Temperature


~2x the spped 1/2 the viscosity

DON”T exceed membrane or filter holder max use Temp - generally 65degC MAX BUT CHECK !


Syringe Pump : Olive Oil 25C
30psi (PressGauge)
 20ml 19mmID Syringe
 0.5sqin >1.0ml/min
0.45um PVDF

50ml syringe 29mmID
> 2.3ml/min


Vacuum vs Pressure
0.45um PVDF

HandPump Vacuum 350mm = -7.0psi max developed Vac Flask Filtration
Syringe Filter 25mmD
Thumb Force ~10lb max
= 20psi ( but RSI problems ???)



47mm MF Calculated
Flow=0,66ml/min x
{ 47/25 }sqd = x 3.5
-= 2.30ml/min
Measured 20ml/6.0min =


Olive Oil

43cps 37C
24cps 54C

Flow is  proportionall to
1/ viscosity

heating speeds up flow
approx x2
for every +20degC


OK ! heat to help dissolve sample into “solvent” matrix
generally let mix cool before filtration to below << 65deg C

On-Cooling the sample itself can crystallise out and completely block the filter membrane and even the Glass Frit or support base of the filter holder

Membrane Filter and Filter Holder

Max Temp

Check the MAX Temperature use for each !

Glass Filtration Equipment

Syringe Pump + Barrel heater

Syringe Dispenser

 250mmHg Vac

use with Syringe Filter 0.45um first run; 2nd run 0.22um for extra sterility

Oils (???) :
“Thin” Oils or Aqueous-based

Oils :  60ccSyringe 0.45um SF
Syringe Heater @ 55degC

10ml Only Extra leverage helps
Thin Oils or Solvents/Aqueous Based

Motorised pump run continuosly
0.45um 1ml/min
Use internal collection Test Tube

0.45um 25mm > 5ml/min
New 33mm SFs 1.75x faster 8cc/min
Heat to 55degC 2x faster 16cc/Min

2-way valve can be problematic with sticky oils ???

Hand VAC Pump
- OK for quick filtration
- a leak-free system is necessary
- can be a bit tedious

250mm Vac
but 350 typical observed

Vac-U-Fill PDF acrobat
0.2um /  0.45um 47mm Membrane
new 90mm Diam 500ml/500ml
Reservoir Bottles (spares)
250ml VFP250
500ml VFP500
1000ml VFP1000

Oils : some tend to soften polystyrene containers
- can crack or tend to “implode”/squash under Vac

Vac-U-Fill preferred for aqueous based mixes, more polar solvents


for auto-filling from sample reservoir - fast for thin low viscosity liquids


for thin aqueous Solutions
- Syringe Filter on Outlet of BTD
- Auto-filling
- extra pressure can be applied by palm of hand to increase speed
- with CARE as device is more delicate

ALL filters tend to block up depending on particulates that actually block the filter pores
- use of coarser pre-filter (glass Fibre) helps speed and the total sample throughput
for best results - match the polarity of the Membrane material with the polarity of the liquid
hydrophillic          :        PES      >          Nylon      >             PVDF       >            PTFE  Hydrophobic
                                               Water-based      polar solvents       polyester Oils         Hydrocarbon-based Oils
these are but generalisations - & it’s very much “trial and error” for each application
PES : OK for medium polarity OIls; eg grapeseed etc
Plastic (Bottle-Top) Filters / Syringes >avoid use of strong solvents
eg acetone > even ethanol is suspect And/Or use of too high as vacuum 200mmHG MAX is OK
even glass bottles run the risk of imploding . . . at higher Vacuum !

VacuCap FastCAP Bottle-Top Filtration
How to . . . acrobat

for “OILS” > the BEST
Filtration Answer

for High Speed / thru’put
PES preferred for
 “polyester” Oils

Olive Oil; Canola, Palm oil, Cottonseed
- all approx the same viscosity
at 25degC 40-60cps at 25C
20-25cps at 55C

multi-Layer SF and pre-filters help
preserver main and can improve flow

The VacuCap Filter is used for sterilization or clarification of a wide variety of fluids.  use for cell culture and serum-containing media liquids

  • have a Supor (hydrophilic PES polyethersulfone) membrane which provides fast flow rates.
  • can draw directly from mix vessel and filters directly into the desired containers, minimizing transfer steps.
    accepts a variety of collection vessels.
  • VacuCap 90 Filter which is designed for volumes of 1–5L
  • have built-in prefilter that increases throughput of viscous or particulate solutions, such as serum-containing media.
  • Polyester membrane support. Acrylic housing.
  • VacuCap Filters are Sterile.
  • come with one piece of tubing per ten filter devices.
    The feedline accessory kit includes tubing and a glass sinker.

PES FastCAP 0.22um 90mm 
#298-9020 >
Now from Thermo
& supplied “sterile” packed


use with Hand Vacuum Pump MityVac 12-MV8010

use with Motorised Vacuum Pump VPJ0332

VacuCap 90
90mm Diam Cap


0.1um for critical sterilisation




0.2umfor sterilisation


Sterile / Fast




1-5Liter volumes . . . Simple Glassware Accessory use

Nalgene FastCap Bottle Filter - Nalgene 298-9020 > & from Thermo

The Nalgene Fastcap Filter works on any bottle that has a neck opening of up to 53mm. The Nalgene FastCap Filter eliminates the need to use threaded glass media bottles.

Place a Nalgene FastCap filter on bottle mouth, attach a vacuum line to the larger center vaccum hose link and your liquid media tube to the smaller tube link and start filtering.

The Nalgene FastCap. . .

  • filters up to 5 liters of liquid.
  • Housing is blue polystyrene; the 90mm filter is made of PES (polyetheresulfone)
  • with a 0.2um pore diameter.. . . for sterility
    use with a disposable 47mm Membrane Filter where necessary
  • Each  filter is packaged in individual hermetically sealed plastic bags.
  • Nalgene FastCap filters are STERILE (gamma radiation sterilized).
  • FastCap filters are sold in individual units or a case of 10 $440- per 10-pk

VacuCap & Fast Cap are very similar in principle ( supply and demand determine Supplier and Chromtech Stock at any time)
Accessory Glassware(GL-45 Bottles/Fittings/Tubing) also available form Chromalytic - Enquire! . . . see Glassware ?

Double CheckValve Dispenser


Other Filtration Devices


ReUsable Filter Holder

IDEAL : Use as a pre-Filter for
Thermo FAST Cap System
Glass Fibre 0.6, 1.7um as deemed necessary
(Order Membrane Disc  separately)
ASK for FastCap PreFilter Kit ( luer tube connectors)

Venting Filters
Capsule Filters
refillable BTD

for detals

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