Hiranuma AQ-300 Coulometric Karl Fischer Moisture Analyzer

Overview

The Hiranuma AQ-300 is a compact, fully automatic coulometric Karl Fischer moisture analyzer engineered for high-precision water content determination in trace-level applications (10 µg to 200 mg H₂O). Unlike volumetric KF systems, the AQ-300 employs electrogenerated iodine via constant-current coulometry—ensuring stoichiometric accuracy without manual reagent standardization. Its core measurement principle follows Faraday’s law: the quantity of iodine generated at the anode is directly proportional to the electric charge passed, enabling absolute quantification of water based on the 1:1 molar reaction between iodine and water in the KF reagent matrix. This architecture delivers superior reproducibility (<2% RSD at 100 µg level), minimal reagent consumption, and intrinsic calibration stability—making it ideal for quality control labs handling pharmaceuticals, lithium battery electrolytes, polymers, and fine chemicals where regulatory-grade trace moisture data are mandatory.

Key Features

• Space-optimized footprint: Measuring only 310 mm wide × 270 mm deep, the AQ-300 fits seamlessly into fume hoods, glove boxes, or crowded QC benches without compromising analytical integrity.
• Predefined method management: Stores multiple measurement condition files—including titration current, endpoint sensitivity, stirring speed, and drift compensation settings—allowing rapid, error-resistant method recall for diverse sample matrices (e.g., solvents, oils, hygroscopic solids).
• Intuitive tactile interface: Dedicated function keys (Start/Stop/Setup), numeric keypad, and context-sensitive on-screen guidance eliminate menu navigation fatigue—reducing operator training time and minimizing input errors during routine analysis.
• Dual RS-232C connectivity: One port synchronizes automatically with certified analytical balances (e.g., Mettler Toledo XP series) for direct sample weight import; the second enables bidirectional communication with LIMS or custom PC software for automated report generation, audit trail logging, and 21 CFR Part 11–compliant electronic signatures.
• Robust coulometric cell design: Platinum generator and detector electrodes with optimized diaphragm geometry ensure stable baseline, fast endpoint detection, and resistance to contamination from halogenated or acidic samples.

Sample Compatibility & Compliance

The AQ-300 accommodates liquid, solid, and gaseous samples via optional accessories—including oven samplers (for volatiles), solid samplers (for powders), and gas-tight syringes (for compressed gases). It meets method validation requirements under ICH Q2(R2) for specificity, linearity, accuracy, and precision. All measurements comply with internationally recognized standards: ISO 8533 (petrochemicals), ASTM E203 (solvents and chemicals), USP (pharmaceutical excipients), and JP 18 (Japanese Pharmacopoeia). The system supports GLP/GMP workflows through configurable user access levels, full audit trail recording (including parameter changes, result edits, and instrument status), and timestamped raw data export.

Software & Data Management

While the AQ-300 operates autonomously via its embedded firmware, its dual RS-232C architecture enables integration with validated third-party software platforms. Raw titration curves, endpoint voltages, consumed charge (coulombs), calculated water mass (µg), and % moisture are transmitted in ASCII format for parsing into Excel, LabWare LIMS, or custom Python-based QA dashboards. Data files include metadata headers (operator ID, sample ID, date/time, method name, balance serial number), satisfying FDA 21 CFR Part 11 requirements when paired with appropriate electronic signature modules and network security controls.

Applications

• Pharmaceutical manufacturing: Residual moisture in lyophilized APIs, tablet granules, and packaging headspace validation.
• Lithium-ion battery R&D: Water quantification in carbonate-based electrolytes (target <20 ppm) to prevent HF formation and SEI layer degradation.
• Polymer synthesis: Monitoring moisture in polyamide, polyimide, and silicone precursors where hydrolysis compromises molecular weight.
• Electronics grade solvents: Certification of acetone, THF, and NMP used in semiconductor cleaning processes.
• Food ingredient testing: Water activity correlation studies in hygroscopic additives (e.g., citric acid, maltodextrin).

FAQ

What is the detection limit of the AQ-300?
The instrument achieves a lower detection limit of 10 µg water per measurement under optimal conditions (low-drift environment, fresh reagent, proper cell conditioning).
Can the AQ-300 perform volumetric Karl Fischer titration?
No—the AQ-300 is exclusively a coulometric system. Volumetric KF analysis requires a separate burette-driven platform such as the Hiranuma AQV-300 series.
Is method validation support available from the manufacturer?
Hiranuma provides IQ/OQ documentation templates and application notes aligned with ASTM E203 and USP , but final PQ must be executed by the end-user lab per local regulatory requirements.
How often does the KF reagent need replacement?
Typical reagent lifetime is 30–50 mL per cell fill, depending on ambient humidity, sample water load, and frequency of use—monitored in real time via the instrument’s built-in reagent exhaustion indicator.
Does the AQ-300 support automatic sample changers?
It does not natively integrate with robotic autosamplers; however, external programmable dispensers with RS-232 command capability can be synchronized via custom scripting.