Metrohm 857 Titrando Automatic Potentiometric Titrator

Overview

The Metrohm 857 Titrando is a high-precision automatic potentiometric titrator engineered for trace-level quantitative analysis in regulated laboratory environments. Based on Metrohm’s fourth-generation analytical platform, it implements a fully digitized electrochemical measurement architecture—where electrode signals, dosing events, temperature readings, and user interactions are captured, timestamped, and stored as discrete digital data points. Unlike analog titrators relying on voltage-to-digital conversion at the instrument level, the 857 Titrando integrates iConnect digital cabling and iTrode smart electrodes to perform A/D conversion directly at the sensor interface. This eliminates signal degradation, improves long-term calibration stability, and ensures full auditability of each measurement step—meeting the foundational data integrity requirements of ISO/IEC 17025, USP , and ICH Q2(R2). Designed for routine QC, pharmaceutical release testing, and environmental compliance labs, the system supports classical potentiometric endpoints (e.g., acid–base, redox, precipitation), Karl Fischer water determination, and controlled-potential (STAT) titrations—all within a single hardware framework.

Key Features

• Digital electrode interface (iTrode + iConnect) enabling real-time electrode diagnostics, serial-number-based calibration history tracking, and automatic firmware version logging
• Dosino smart burette modules with integrated micro-stepper motors and ceramic piston technology—delivering volumetric accuracy ≤0.02% RSD and eliminating dead-volume errors across 1–50 mL ranges
• Modular expansion architecture supporting up to 12 independent Dosino units via 800-series bus, enabling parallel multi-reagent titrations or sequential multi-step protocols
• Lab Link communication protocol for deterministic, low-latency synchronization between titrator, balance, autosampler, and barcode scanner—ensuring precise mass-triggered dosing and sample ID binding
• Integrated temperature compensation using dual-sensor inputs (Pt 1000 or NTC), with configurable interpolation algorithms per method to correct for thermal drift in endpoint detection
• Embedded polarization control (Ipol/Upol) for amperometric and coulometric applications, including iodine generation for KF titration and controlled-current redox titrations

Sample Compatibility & Compliance

The 857 Titrando accommodates aqueous, non-aqueous, viscous, and suspended-phase samples through interchangeable electrode housings (e.g., double-junction reference, shielded Ag/AgCl, platinum ring, glass pH), combined with programmable stirring profiles and dynamic dosing rate optimization. All hardware and software components comply with IEC 61326-1 (EMC for laboratory equipment) and IEC 61010-1 (safety). Data handling conforms to FDA 21 CFR Part 11 requirements: electronic signatures are role-based and time-stamped; audit trails record all method modifications, result overrides, and user logins; and raw measurement data—including raw mV/pH vs. volume curves, derivative plots, and intermediate calculation steps—are retained unaltered in encrypted tiamo database files (.tmd). The system supports 21 CFR Part 11-compliant validation documentation packages, including IQ/OQ/PQ protocols and risk-based test scripts aligned with Annex 11 and GAMP 5.

Software & Data Management

Controlled exclusively by tiamo™ software (v3.x or later), the 857 Titrando provides a validated, method-centric workflow environment. Methods define not only titration parameters but also sample metadata fields, reporting templates, pass/fail criteria, and automated post-processing (e.g., blank subtraction, dilution factor application, unit conversion). All results—including raw curves, statistical summaries (mean, SD, RSD, confidence intervals), and chromatogram-style overlay comparisons—are exportable to CSV, PDF, or XML formats. The embedded relational database stores methods, calibration records, user permissions, instrument logs, and audit trail entries in ACID-compliant SQLite format. Optional tiamo Connect enables remote monitoring, centralized method deployment across lab networks, and integration with LIMS via HL7 or RESTful API.

Applications

• Pharmaceutical QC: Assay of active ingredients (e.g., chlorides in antibiotics), residual solvent quantification (KF), and excipient acidity profiling per USP
• Food & Beverage: Total acidity (TA), salt content (argentometric), sulfite determination (iodometric), and free fatty acid titration in oils
• Environmental: Chloride in wastewater (Mohr method), cyanide in effluents (silver nitrate potentiometry), and alkalinity profiling in drinking water per EPA 310.1
• Chemical Manufacturing: Catalyst activity assessment (redox titration), purity verification of inorganic salts, and acid number determination per ASTM D974
• Academic Research: Development of novel titration protocols involving multi-step equilibria, kinetic endpoint detection, or coupled electrochemical–titrimetric assays

FAQ

Does the 857 Titrando support ASTM or ISO standard-compliant titration procedures?
Yes—preconfigured method templates for ASTM D1556 (chloride), ISO 9964-1 (acid number), and ISO 787-12 (pH of pigments) are available in tiamo Library and can be validated per laboratory SOPs.
Can the system perform simultaneous multi-parameter titrations (e.g., pH + mV + temperature)?
Yes—the dual measurement input allows concurrent acquisition of potentiometric (U/mV) and thermometric (T/°C) signals, enabling thermometric endpoint detection alongside conventional potentiometric mode.
Is tiamo software qualified for use in GxP-regulated environments?
Yes—tiamo v3.3+ is delivered with a complete validation support package, including installation qualification (IQ) checklists, operational qualification (OQ) test scripts, and computer system validation (CSV) documentation aligned with Annex 11 and ALCOA+ principles.
How is data backup and long-term archiving handled?
tiamo supports scheduled database backups to network drives or NAS devices; archived .tmd files retain full traceability—including raw sensor data, user actions, and system timestamps—for ≥25 years without dependency on proprietary runtime environments.
What peripheral devices are certified for direct integration?
Metrohm-certified peripherals include the 863 Compact Auto-sampler, 852 pH Meter (for hybrid pH–potentiometric workflows), 856 Professional Sample Processor, and all generations of Dosimat and Dosino modules—each with documented firmware compatibility matrices.