SFA-20 Stopped Flow Device

Overview

The SFA-20/SPEX series of stopped-flow rapid-kinetics accessories offers versatility for spectroscopic monitoring of fast reactions in solution.

What is it?

  • One of the most frequently used rapid kinetics techniques.
  • Used to study fast kinetics reactions (in the millisecond timescale) between two mixed reactants.
  • Many applications in the chemistry and biochemistry fields.

    • Quenching studies
    • Energy transfers
    • Enzymes kinetics

How does it work?

  • Under pneumatic drive activation, the two small volumes of solutions are driven from high performance syringes through a high efficiency mixer.
  • The resultant mixture passes through a measurement flow cell and into a stopping syringe.
  • Just prior to stopping, a steady state flow is achieved.
  • As the solution fills the stopping syringe, the plunger hits a block, causing the flow to be stopped instantaneously.
  • Using appropriate techniques, the kinetics of the reaction can be measured in the cell.

Features

  • Dead time < 8 ms
  • Observation cell optimized for best performance with SPEX® instruments
  • Integrates into any current SPEX® fluorescence system
  • Multi-mixing ability
  • Flexible thermostat format
  • Sample’s path constructed of chemically inert Kel-F™, silica, Teflon®, and glass
  • Crush-resistant flexible umbilical

Teflon® is a registered trademark of E.I. DuPont de Nemours, Inc.


Manufactured by HORIBA

Specifications

Dead Time:

<8 ms

Dead Volume:

700 µL (SFA-20 and SFA-20mx); 350 µL (SFA-20M and SFA-20mxM)

Window Sizes:

3 mm wide

Flow cell's beam height:

15 mm from base of cell to center of window

Min. vol. per determination:

100 µL per reactant

Observation path:

3 mm for excitation and 3 mm for emission

Observation cell:

Silica

Fill-syringe volume:

5mL

Windows:

3 mm wide x 10 mm high for excitation and emission, specifically designed for FluoroMax® and FluoroLog® instruments

Adjustable stop volume:

Available

Mixing ratio:

Up to 20:1

Temperature range:

5 - 80°C

Piston Drive:

Manual drive is standard; Pneumatic control optional. We recommend, however, the SFA-20mx/SPEX and SFA-20mxM/SPEX Umbilical length = 600 mm (SFA-20/SPEX and SFA-20mx/SPEX); 300 mm (SFA-20M/SPEX and SFA-20mxM/SPEX); other lengths on request

Drive syringes:

2.5 mL for SFA-20/SPEX; 1 mL for other models High-efficiency T-format mixer: Available for SFA-20/SPEX and SFA-20M/SPEX; 10 µL delay available for SFA-20mx/SPEX and SFA-20mxM/SPEX; longer delays upon request