Xuxin ST-1513 Coulometric Karl Fischer Moisture Analyzer
| Brand | Xuxin Instrument |
|---|---|
| Origin | Beijing, China |
| Manufacturer | Xuxin Instrument Equipment Co., Ltd. |
| Type | Coulometric Moisture Tester |
| Model | ST-1513 |
| Measurement Range | 1 µg – 200 mg H₂O |
| Accuracy | ±3 µg (for 10–1000 µg), ±0.3% (for >1000 µg) |
| Resolution | 0.1 µg |
| Power Consumption | ≤60 W |
| Operating Temperature | 5–40 °C |
| Relative Humidity | 10–80 % RH |
| Power Supply | 220 V ±10%, 50 Hz |
| Dimensions (W×D×H) | 326 × 246 × 180 mm |
| Weight | 4.14 kg |
Overview
The Xuxin ST-1513 Coulometric Karl Fischer Moisture Analyzer is a fully automated benchtop instrument engineered for trace-level water quantification in solid, liquid, and gaseous samples using the coulometric titration principle per ASTM D6304 and ISO 12937. Unlike volumetric KF methods, coulometric detection generates iodine electrochemically at the anode in real time, enabling ultra-sensitive measurement down to 0.1 µg water with high reproducibility and minimal reagent consumption. This architecture eliminates calibration drift associated with burette delivery systems and ensures stable baseline performance over extended operation—critical for QC laboratories processing high-throughput pharmaceutical intermediates, hygroscopic APIs, or moisture-sensitive catalysts.
Key Features
- High-resolution coulometric detection with 0.1 µg resolution and dual-circuit balanced titration control, minimizing endpoint overshoot and improving repeatability across matrix-varied samples.
- Intelligent electrolyte management: automatic blank current compensation and drift-based equilibrium point correction ensure accurate baseline subtraction even during prolonged analysis of low-moisture samples (e.g., <100 ppm).
- Hermetically sealed electrolytic cell with optimized PTFE-sealed septum design—reduces ambient moisture ingress, shortens equilibration time (<2 min typical), and extends electrolyte service life by up to 40% versus conventional cells.
- Programmable electrolysis delay (0–300 s) accommodates slow-release or diffusion-limited samples such as polymers, powders, or viscous resins without manual intervention.
- Multi-unit auto-conversion engine supporting direct display in µg, mg/L, ppm, or wt%—with unit-specific calculation formulas stored and recalled per method template.
- Real-time reagent health monitoring: algorithmic detection of iodine generation inefficiency and elevated background current triggers visual/audible alerts prior to analytical failure.
- Configurable UI: full English or full Chinese language mode selectable via touch interface; supports GLP-compliant operator login with role-based access control.
Sample Compatibility & Compliance
The ST-1513 demonstrates robust compatibility with diverse sample classes including polar solvents (methanol, ethanol, acetone), non-polar hydrocarbons (hexane, toluene), reactive esters and acid chlorides, and thermally labile compounds (e.g., β-lactams). Its coulometric cell design avoids side reactions common in volumetric systems when analyzing aldehydes or ketones. The analyzer complies with key regulatory frameworks: data integrity features align with FDA 21 CFR Part 11 requirements (audit trail, electronic signature support, user authentication); measurement uncertainty reporting conforms to ISO/IEC 17025 Annex A.5; and routine verification protocols follow USP <921> and EP 2.5.12 for pharmaceutical moisture testing.
Software & Data Management
Embedded firmware supports method-driven workflows with up to 100 user-defined test protocols, each storing sample ID, electrode history, solvent batch, and environmental log (temperature/humidity). Raw current-time curves and titration endpoints are exportable in CSV format. Optional PC software enables advanced statistical analysis (RSD, recovery, linearity), trend charting across batches, and integration into LIMS via ASTM E1384-compliant XML output. All audit trails—including parameter edits, result overrides, and calibration events—are timestamped, immutable, and exportable for internal QA review or regulatory inspection.
Applications
- Pharmaceutical: Quantification of residual solvents and hydrate water in active pharmaceutical ingredients (APIs) per ICH Q5C guidelines.
- Petrochemical: Moisture determination in transformer oils (ASTM D1533), jet fuels (ASTM D6304), and lubricants where water accelerates oxidation.
- Electronics: Verification of moisture content in solder pastes and encapsulant resins to prevent popcorning during reflow soldering.
- Agrochemicals: Stability assessment of wettable powders and emulsifiable concentrates where hydration impacts shelf life.
- Academic research: Kinetic studies of hydrolysis reactions requiring sub-10 µg water resolution in anhydrous reaction media.
FAQ
What is the minimum detectable water mass using the ST-1513?
The instrument achieves a lower detection limit of 1 µg water with 0.1 µg resolution under optimized conditions (dry environment, fresh electrolyte, calibrated electrodes).
Can the ST-1513 analyze samples containing ketones or aldehydes?
Yes—the coulometric cell configuration minimizes side reactions compared to volumetric KF systems; however, use of specialized aldehyde-compatible electrolyte (e.g., Hydranal-Coulomat AG) is recommended for optimal accuracy.
Does the system support 21 CFR Part 11 compliance out-of-the-box?
Audit trail logging, electronic signature capability, and user permission tiers are enabled by default; full Part 11 validation requires site-specific IQ/OQ documentation and optional password policy enforcement modules.
How often must the electrolyte be replaced?
Typical service life is 50–80 tests depending on sample water load and ambient humidity; the built-in reagent health monitor provides predictive alerts based on real-time current efficiency decay.
Is external calibration required before each analysis?
No—coulometric KF is an absolute method; calibration is inherent to Faraday’s law. System verification uses certified water standards (e.g., Hydranal 1.00 mg/mL) at start-of-day or after maintenance.
