Metrohm 905/907 Advanced Automatic Potentiometric Titrator with Dosino™ Technology

Overview

The Metrohm 905/907 Advanced Automatic Potentiometric Titrator is a high-precision, modular electrochemical platform engineered for reproducible, traceable, and fully automated potentiometric titrations in regulated laboratory environments. Based on the proprietary Intelligent Electrochemistry™ architecture introduced by Metrohm in 2009, this system integrates digital sensor communication, embedded calibration metadata, and real-time electrode diagnostics into a unified hardware-software ecosystem. Its core measurement principle relies on potentiometric endpoint detection—monitoring potential shifts across an ion-selective or redox-sensitive indicator electrode relative to a stable reference electrode—enabling quantitative determination of analytes such as acids, bases, halides, metal ions, and water (via Karl Fischer coulometric or volumetric modes). Designed for compliance-critical workflows, the instrument supports dual-channel potentiometry, dynamic endpoint titration (DET), constant incremental titration (MET), and preset endpoint titration (SET), with native integration of STAT (controlled-potential) and KF volumetric water determination methods.

Key Features

• Dosino™ Multi-Channel Dosing Units: Patented plug-and-play dosing modules mount directly onto reagent bottles via universal adapters—eliminating benchtop footprint and enabling rapid, tool-free exchange. Transparent polymer housings allow visual bubble detection and valve position monitoring; full automatic rinsing and priming are executed without manual disassembly.
• Intelligent Electrode & Cable System: Each electrode and measurement cable contains an embedded EEPROM chip storing serial number, calibration history, material composition, and validity timestamps—automatically recognized upon connection and logged in audit trails per FDA 21 CFR Part 11 requirements.
• Modular Expansion Architecture: Four MSB (Metrohm Serial Bus) ports support up to two 807 Dosino units, four 801 magnetic stirrers, or configurable 804 titration stands (with 802 rod stirrers) and 803 KF titration stations. Optional 867 pH or 856 conductivity modules extend multi-parameter capability.
• Real-Time Data Acquisition: 100 ms sampling interval with 0.001 pH / 0.1 mV / 0.1 °C resolution. Simultaneous measurement of pH, mV, temperature, and current (Ipol/Upol) enables advanced redox and polarization studies.
• Touchscreen & Remote Operation: 90 × 120 mm color LCD with intuitive “Magic Touch” interface for one-click method launch; full remote control via PC-Control software or tiamo™ suite over LAN/internet (LabLink™).

Sample Compatibility & Compliance

The 905/907 platform accommodates aqueous and non-aqueous matrices—including organic solvents (e.g., methanol, chloroform), viscous samples (oils, polymers), and heterogeneous suspensions—when paired with appropriate electrodes (e.g., Ag/AgCl, Pt, glass, ion-selective, or double-junction references). It complies with ISO 8655-7 (volumetric apparatus), ASTM E202–22 (Karl Fischer titration), and USP (water determination). All electronic records include electronic signatures, user authentication (password + smart card), and immutable audit trails meeting GLP, GMP, and FDA 21 CFR Part 11 criteria. Built-in electrode validation routines (GLP-certified test) verify slope, offset, and response time before each sequence.

Software & Data Management

tiamo™ software serves as the central data management hub—supporting relational database servers, parallel titration scheduling, customizable report templates (PDF/CSV/XLS), and automated backup via PCMCIA or USB flash storage. The system implements role-based access control, method versioning, and cryptographic hash verification for raw data integrity. All titration curves, derivative plots, equivalence point evaluations (fixed EP, inflection, pK_a, HNP), and concentration calculations are stored with full metadata: operator ID, timestamp, environmental conditions, electrode ID, and reagent lot numbers. Data export conforms to ASTM E1394 and LIMS-compatible formats.

Applications

• Determination of total acidity in wines, edible oils, and biodiesel (AOAC 965.34, ISO 660)
• Chloride quantification in drinking water and wastewater (ISO 9297, EPA 300.0)
• Karl Fischer volumetric water content in pharmaceutical excipients and active ingredients (USP , Ph. Eur. 2.5.12)
• Redox titrations of Fe²⁺/MnO₄⁻, I₂/S₂O₃²⁻, and Ce⁴⁺/As(III) in metallurgical and environmental samples
• pK_a profiling and buffer capacity analysis in formulation development
• Endpoint detection in complexometric titrations (EDTA vs. Ca²⁺/Mg²⁺) for hardness testing

FAQ

Does the 905 model support Karl Fischer titration out-of-the-box?
Yes—the 905 includes editable method templates for volumetric KF titration and STAT mode, while the 907 ships with preloaded, validated KF and STAT methods.
Can the system perform simultaneous multi-parameter measurements during titration?
Yes—it acquires pH, mV, temperature, and current (Ipol/Upol) synchronously at 100 ms intervals, enabling real-time reaction mechanism analysis.
Is tiamo™ software included with the instrument purchase?
tiamo™ Basic is supplied standard; tiamo™ Professional (with database server, LIMS integration, and advanced reporting) is available as an optional license.
How does the system ensure traceability under GLP conditions?
All operations generate timestamped, digitally signed audit trails containing user identity, method version, electrode calibration status, reagent consumption, and raw sensor output—fully compliant with Annex 11 and ALCOA+ principles.
What types of external devices can be connected via USB or MSB interfaces?
USB supports sample processors (e.g., 863 Compact Sample Processor), analytical balances, and printers; MSB interfaces connect Dosino units, stirrers, KF ovens, and auxiliary modules (pH/conductivity).