Pioneering Instrumentation for Transient Kinetics & Spectroscopy

Rapid Mixing Devices

Product Code: SFA-20 and Variants

The SFA-20 rapid mixing accessory has remained a popular choice for users who want to add a stopped-flow capability or simply a means of rapidly mixing reagents in the context of a commercial UV/Vis or fluorescence instrument. It may be adopted as an entry level stopped-flow device but is capable of producing results for genuine research applications.

It has a nominal deadtime < 8ms, allowing reaction rates of up to 100 s-1 to be monitored, depending on the response time of the spectrometer.

High precision, research grade, gas-tight syringes are used and are available in volumes from 250 µl to 5 ml. Variable ratio mixing applications are readily accommodated since the syringes are mounted outside the thermostatically controlled sample circuit, allowing easy and rapid replacement. This also prevents any possibility of leaks at low temperatures.

The syringes are mounted on a rigid drive platform ensuring that the flow is stopped precisely and instantaneously. This platform and the syringe mounting blocks are extremely resistant to chemical attack. The thermostatted sample circuit itself is constructed from materials which also provide optimum chemical resistance. Reagents travel in this inert sample circuit through an umbilical cord to the flow cell where they are mixed by a high efficiency T-format mixer.

The cell offers both 2 mm and 10 mm optical path lengths as standard. The standard flow cell supplied with the SFA-20 Series will fit any UV/Visible spectrophotometer or spectrofluorimeter having standard 1 cm cuvette holder and a 15 mm beam height. However, flow cells can be tailored for instruments with different beam height and optical geometry.

Options for the SFA-20 series included:

  1. An anaerobic kit to extend the use of the SFA-20 to applications where oxygen must be excluded.

  2. A pneumatic drive attachment for enhanced shot-to-shot reproducibility.

  3. A conductivity cell and detector is also available allowing stopped-flow conductivity experiments to be performed using the SFA-20 drive unit.

  4. A range of different size drive syringes for variable ratio mixing.

Rapid Kinetic Accessory - Microvolume Version
Product Code SFA-20M

The SFA-20M is a microvolume version of the standard accessory. With a dead volume of just 350 µl per reagent, it is ideally suited to leading edge research where only small quantities of novel or expensive materials are available.

Rapid Kinetic Accessory - Multi-mixing Version
Product Code SFA-20mx

The SFA-20mx incorporates two mixers separated by a 10 µl delay loop. This enables two reagents to be mixed prior to a third reagent being introduced and mixed immediately before the observation chamber. It can also be used for single mixing and 2:1 ratio single mixing without the need to change syringes.

Rapid Kinetic Accessory - Microvolume Multi-mixing Version
Product Code SFA-20mxM

The SFA-20mxM combines the benefits of microvolume operation with multi-mixing capabilities.

Note: The SFA-20 accessory can be used on a wide range of spectrophotometers and fluorimeters e.g. Agilent (Hewlett Packard), Hitachi, PTI, Shimadzu, Kontron, ISS etc. Check with TgK Scientific for compatibility with your instrument.

Optimized Versions

  1. SFA-20/ HITACHI Rapid Kinetics Accessory optimised for use with Hitachi Fluorimeter

  2. SFA-20/ PERKINELMER Rapid Kinetics Accessory optimised for use with Perkin Elmer Fluorimeter

  3. SFA-20/ VARIAN Rapid Kinetics Accessory optimised for use with Cary instruments

  4. SFA-20/ BECKMAN Rapid Kinetics Accessory optimised for use with Beckman DU 7000 Series

  5. SFA-20/ SPEX Rapid Kinetics Accessory optimised for use with HoribaJY FluoroLog and FluoroMax

Note: Multi-Mixing and Micro-volume versions of the above are available on request.


Special versions of the SFA-20 are available on request.