Hand-wash-cuvetteHow can a quartz cuvette be properly cleaned?

The Zetasizer has a flow cell [ZEN0023] used in conjunction with either the titrator, the NanoSampler, or as a chromatography or field flow fractionation detector. A similar flow cell [ZMV1008] is also in use with the Zetasizer microV when used as a molecular weight detector in conjunction with the OmniSEC software. Advanced cuvettes may also be used in UV-Vis, fluorescence & circular dichroism spectrophotometers, MALLS as well as goniometer systems and other specialized optical detection. If the signal from the quartz cell is very noisy, or the perceived sensitivity is lower than in the past, here are a few steps to thoroughly clean the quartz flow cell. A simple method is to use Hellmanex. Alternatively, use syringes, a cuvette washer or Pasteur pipettes for the actual fluid transfer:

Ten steps to clean a flow cell

  1. Disconnect the flow cell from the system (i.e. the titrator, the NanoSampler, or your SEC system) so that the cuvette is separate from the rest of the system
  2. Rinse with copious amounts (~10mL) of deionized water to flush out any loose debris
  3. Rinse with a couple of syringes of methanol (~3mL), let the flow cell rest filled with methanol for 2 minutes
  4. Rinse with copious amounts (~10mL) of deionized water to flush out any remaining methanol
  5. Rinse with a couple of syringes of 1 M NaOH (~3mL), let the flow cell rest filled with NaOH for 60 secconds
  6. Rinse with copious amounts (~10mL) of deionized water to flush out any remaining NaOH
  7. Flush with (~5%) acetic acid, let the flow cell rest filled with acetic acid for 30 seconds
  8. Rinse with copious amounts (~10mL) of deionized water to flush out any remaining acid and let flow cell rest with water for 5 minutes
  9. Rinse with copious amounts (~10mL) of deionized water as an extra rinse
  10. Rinse with a couple of syringes of your running buffer and reconnect the flow cell to the system

With this 10-step cleaning program your flow cell should be squeaky clean again. It is not advised to use an ultrasonic cleaning bath as this may break the delicate cuvettes. Long exposure to strong bases or acids can cause the cell windows to go dull, so this should definitely be avoided. Overall, with good treatment and clean samples the flow cell should last a very long time. Good luck with your measurements!

Previously

If you have any questions, please email me at ulf.nobbmann@malvern.com. Thanks! While opinions expressed are generally those of the author, some parts may have been modified by our editorial team.