CVS – Frequently Asked Questions

Problems with Dilution Titration (suppressor determination)

  • Conditioning is taking a long time and a standard deviation < 0.5% cannot be achieved.

  • The evaluation criterion has been reached. However, no results are being displayed.

  • The curve obtained from the sample looks different to that from the calibration.

Problems with MLAT/LAT (brightener determination)

  • The reproducibility of results is worse than expected.

  • I am getting non-reproducible measurement curves (cyclic voltammogram).

  • I am getting negative or no results.

  • The measurement of the intercept value is taking a long time or is not completed.

Problems with Response Curve (leveler determination)

  • Measuring the electrolyte value is taking a long time or is not completed.

Problems with the measurement

  • Are CVS measurements temperature-dependent?

  • The measuring signal for the VMS is fluctuating.

  • The signal is not decreasing despite suppressor addition.

  • The electrode test is failing.

  • The peak is no longer recognized.

  • Conditioning is taking a long time.

  • The measurement curves are noisy.

  • Is it possible to repair a defective driving axle (6.1204.x010 or 6.1204.x20)?

  • The measured values are widely scattered.

Problems with the hardware

  • An electrode connector on the electrode cable is broken.

  • Solution is leaking between the 894 Professional CVS and the measuring head.

  • I am getting an error message. The 800 Dosino cannot be actuated by the 894 Professional CVS.

  • I am getting an error message that the dosing unit data cannot be read.

  • The dosing unit is blocked and/or leaking.

  • The status LED of the 800 Dosino is flashing quickly and the dosing unit is not being recognized.

  • The membrane pumps of the 843 Pump Station are not operating at full pump capacity.

  • The peristaltic pump on the sample changer is not transferring the entire sample to the measuring vessel.

General problems

  • How often should the dosing units be prepared?

  • Preparing the Dosinos is taking a long time. Is it possible to speed up this step?

  • What preparatory steps need to be taken before shutting down the measuring system?

  • At what intervals should a dosing unit be cleaned?

  • How should the electrodes be stored?

  • How frequently do the electrodes need to be conditioned?

  • The measuring signal in VMS is exceptionally small and conditioning in VMS is taking a long time. What is the reason for that?

  • The measurement curves are noisy. What is the reason for that?

  • Can measurements made using other software be used in viva?

  • How should the additives be stored?

Rotating disk electrode

  • Can platinum electrode tips be polished?

  • Can Metrohm polish platinum electrode tips?

  • How do I clean my platinum electrode tip?

  • The electrode surface of the platinum electrode tip is coated with a foreign metal (Cu, Sn, etc.). What can I do?

  • How temperature-resistant is the platinum electrode tip?

  • Can the platinum electrode tip be treated in an ultrasonic bath?

  • Does the Pt RDE diameter affect my analysis results?

Reference electrode

  • My reference electrode has dried out. Can I regenerate it again?

  • Until now, I have always used diluted H2SO4 as a bridge electrolyte. Can I use another electrolyte instead of KNO3?

  • How often do I need to change the reference electrolyte?

  • How often does the bridge electrolyte need changing?

Auxiliary electrode

  • The electrode surface of the auxiliary electrode is coated with a foreign metal (Cu, Sn, etc.). What can I do?

  • Is polishing the platinum pin of the auxiliary electrode allowed?