Metrohm^® 842 Titrando^® pH STAT Titrator and Synthesis Controller

STAT titration

The determination of the activity of an enzyme or the monitoring of the release kinetics of antacid drugs requires a titrator that rapidly adjusts a predefined pH value and keeps it constant over a long time period. The 842 Titrando's controller has been optimized for this task and can also be used to determine the kinetics of acid-base or redox reactions.

Tandem dosing is a new feature offered by the 842 Titrando. To avoid a break in dosing when the buret is refilled, a second buret takes over the dosing operation without any interruption. This means that fast reactions and those reactions that have a high-reagent consumption can be monitored without any loss of accuracy.

Expanded evaluation criteria allow you to determine dosing rates and thus the reaction rate over the whole measuring period or within predefined time windows. Fixed endpoints for the measured quantities—that is for volume, time and measuring value—are also available.

Controlled dosing—liquid handling made easy

Tasks performed in the synthesis laboratory differ from those in titration. Typical synthesis work involves maintaining a constant pH value or performing a multiple dosing operation under strictly defined conditions. A preset volume has to be added to a solution during a given time span. During the controlled dosing procedure, the parameters pH (or potential) and temperature are continuously monitored and registered. This results in a complete documentation of the synthesis sequence.

Dosing can also be carried out continuously in the tandem mode with two Dosinos^®. This converts the 842 Titrando into a chemically resistant, high-precision pump. When a monitored parameter infringes the set limit values, it is up to you to decide whether to continue the dosing or interrupt and restart it manually or automatically, again applying limit values.

A new feature of the 842 Titrando is its ability to perform control tasks. External instruments can be controlled by means of freely programmable TTL signals or by communication via an RS-232 interface. This opens up the possibility of remotely controlling external heating or cooling apparatus, pumps or similar devices.

Additional features

For dosing, the 842 Titrando uses the unique Dosino system. Two Dosinos with their reagent bottles can be accommodated in space-saving fashion on the Titrando itself, which can control up to four Dosinos. Besides the enzymatic and the pH STAT titration (STAT), the 842 Titrando offers the following modes:

• Controlled dosing (DOS)
• Endpoint titration (SET)
• Measuring pH, mV and temperature (MEAS)
• Additional dosing and liquid handling functions to facilitate sample preparation

The 842 Titrando comes equipped with one measuring interface; a further measuring interface can be retrofitted. It is compatible with PC Control 4.0, 840 Touch Control and tiamo™ 1.1.