QuickSplit™ Fixed Flow Splitters

  • The ASI Fixed Flow Splitter divides inlet flow into two, three or four channels
  • Factory preset split ratios from 1:1 to 20,000:1
  • Fluid resistor technology replaces long capillary tubing to create split ratio
  • Simple low cost design that does not require any calibration or adjustment
  • Small size allows closer placement to the detector
  • Ultra low dead volume fluidic design for minimal dispersion
  • Input flow rate from 0.1 mL/min. up to 1 L/min. (Higher flow rate are available by request)
  • Stable and reproducible split flows are not affected by viscosity or pressure changes in post-column applications
  • Maximum 350 bar operating pressure
  • Available in binary, three and four port configurations

The ratio of the fluid resistor values determines the split ratio.  This ratio is calibrated within a +/- 10% tolerance range, assuming that there is no pressure drop down stream from the splitter.  Input flow rate may be adjusted to compensate for variation within tolerance.  For example, a 10% increase in input flow rate will yield a 10% flow increase at both high and low flow channels.  The pressure drop specification for all input flow ranges is 500 PSI maximum with water at the calibration flow rate.  When ordering, please specify the actual inlet flow rate if it is significantly different from the default calibration flow rate.

Typical uses for post-column flow splitting

Multiple detectors:

Split between 2 or more detectors such as mass spec and evaporative light scattering, UV, or IR.  This is especially important when one of the detectors is destructive, such as Mass Spectroscopy and ELS.


Reduce the flow rate from the column to a lower flow rate that the mass spec can work efficiently at. Chromatography methods are often using flow rates of 0.5 to 2 mL/min., which are too high for most mass spec.  Flow splitting is a way to reduce the flow rate down to flow rates suitable for the mass spec.

Although there are pumps that can deliver flow rates low enough to be compatible with mass spec, many practical reasons prevent Chromatographers from changing methods that are already proven to work at higher flow rates: reluctance to change to a different column from one that is familiar and accepted; FDA regulations and S.O.P’s that make any changes in methods burdensome; the ease of operation at higher mL/min. flow rates compared to µL/min. flow rates.  Flow splitting allows the chromatographer to take a proven method that works at higher flow rates and quickly integrate mass spec or multiple detectors without re-developing the method.

Fixed Flow Splitter General Description

Fixed Flow Splitter Performance Data

620/630/640 Series Fixed Flow Splitters General Installation Instruction