Metrohm Eco Coulometric Karl Fischer Moisture Analyzer

Overview

The Metrohm Eco Coulometric Karl Fischer Moisture Analyzer is a purpose-engineered, entry-level coulometric titration system for precise and reliable quantification of trace water content in liquids, solids, gases, and viscous materials. Based on the electrochemical generation of iodine via controlled current application—per the classical Karl Fischer reaction—the instrument delivers direct stoichiometric determination of water without reagent standardization. This principle ensures high specificity for H₂O, minimal matrix interference, and exceptional sensitivity down to 10 µg absolute water mass. Unlike volumetric KF systems, the coulometric method eliminates variability from burette calibration, syringe accuracy, or reagent stability, making it the preferred technique for low-moisture applications in pharmaceuticals, polymers, lithium-ion battery electrolytes, and fine chemicals.

Key Features

• Fully automated coulometric titration with integrated generator and detector electrodes, optimized for robust baseline stability and rapid endpoint detection.
• Compact, benchtop design engineered for space-constrained QC labs while maintaining Swiss manufacturing precision and long-term operational reliability.
• Intuitive touchscreen interface with guided method setup, real-time titration curve visualization, and context-sensitive help—requiring minimal operator training.
• Compliant architecture supporting GLP-compliant data handling: user access levels, electronic signatures (when paired with Metrohm’s tiamo™ software), and configurable audit trails.
• Flexible sample introduction: direct injection via syringe for liquids; seamless integration with Metrohm 885 Compact Oven or 883 KF Oven for thermally driven moisture release from solids, powders, and hygroscopic matrices.
• Low maintenance design featuring sealed, long-life electrolyte cells and automatic cell conditioning routines—reducing downtime and consumables cost over instrument lifetime.

Sample Compatibility & Compliance

The Eco Coulometer accommodates a broad spectrum of sample types—including solvents, oils, pharmaceutical actives, excipients, catalysts, and polymer pellets—provided they are compatible with methanol-based or chloroform-free KF reagents (e.g., Hydranal-Coulomat AG or Metrohm Coulomat AG-H). For solid or heterogeneous samples, coupling with a programmable heating oven enables controlled thermal desorption of bound water under inert atmosphere, ensuring quantitative recovery without decomposition. The system supports compliance with key regulatory frameworks: USP , EP 2.5.12, ASTM E203, and ISO 760—all of which recognize coulometric KF as the reference method for sub-100 ppm moisture analysis. When configured with tiamo™ software and networked authentication, the platform meets FDA 21 CFR Part 11 requirements for electronic records and signatures.

Software & Data Management

While the Eco analyzer operates autonomously via its embedded firmware, full data traceability and advanced reporting are achieved through integration with Metrohm’s tiamo™ software (v3.3+). tiamo™ provides validated workflows for method validation (linearity, accuracy, repeatability per ICH Q2(R2)), customizable report templates aligned with internal SOPs or external audit requirements, and secure database archiving with time-stamped audit logs. All raw titration curves, calculation parameters, reagent lot tracking, and environmental metadata (e.g., ambient temperature, humidity) are retained for retrospective review—essential for regulatory inspections and root-cause investigations.

Applications

• Pharmaceutical Quality Control: Residual moisture in lyophilized APIs, tablet coatings, and sterile packaging headspace.
• Electrolyte Purity Testing: Water quantification in LiPF₆-based battery electrolytes where H₂O < 10 ppm directly impacts SEI formation and cell cycle life.
• Polymer Manufacturing: Moisture monitoring in polyamide, polyacetal, and polycarbonate resins prior to extrusion or injection molding.
• Chemical Synthesis: Real-time water tracking in Grignard reactions, organometallic preparations, and anhydrous solvent certification.
• Food & Flavor Industry: Low-level moisture in essential oils, emulsifiers, and powdered dairy ingredients affecting shelf-life and microbial stability.

FAQ

What is the difference between coulometric and volumetric Karl Fischer titration?
Coulometric KF generates iodine electrochemically at the anode in proportion to applied current and time—ideal for samples containing ≤1000 ppm water. Volumetric KF dispenses pre-standardized iodine solution from a burette and is better suited for higher water concentrations (>100 ppm).

Can the Eco analyzer be used for solid samples?
Yes—when coupled with Metrohm’s 885 Compact Oven or 883 KF Oven, the system enables controlled thermal extraction of water from solids, ensuring complete release without degradation.

Does the Eco support 21 CFR Part 11 compliance?
Out-of-the-box hardware does not include electronic signature capability; however, full Part 11 compliance is achievable when operated with validated tiamo™ software, network authentication, and documented system qualification (IQ/OQ/PQ).

What reagents are compatible with the Eco Coulometer?
The system is validated for use with single-component anolyte/catholyte systems (e.g., Hydranal-Coulomat AG) and two-component reagents (anolyte + catholyte), including chloroform-free formulations required by modern EHS policies.

Is method validation support available?
Metrohm provides application notes, IQ/OQ documentation templates, and method validation protocols aligned with ICH Q2(R2) and USP general chapters—available upon request through authorized distributors or Metrohm Application Support Centers.