Kyoto Kyoritsu WAK-COD-WR COD Test Kit (10,000 mg/L Range)

Overview

The Kyoto Kyoritsu WAK-COD-WR is a pre-calibrated, ready-to-use colorimetric test kit engineered for rapid, field-deployable determination of Chemical Oxygen Demand (COD) in wastewater, industrial effluents, and surface water samples. Based on the standardized dichromate oxidation method (JIS K 0102, ISO 6060, and ASTM D1253), this kit employs sealed glass vials containing precise amounts of potassium dichromate, sulfuric acid, and silver sulfate catalyst. Upon sample addition and controlled heating, organic matter is oxidized; the resulting color change—proportional to the consumed oxygen equivalent—is quantified visually against a calibrated color chart or with a portable photometer. The WAK-COD-WR variant is specifically optimized for high-range applications up to 10,000 mg/L COD, making it suitable for raw sewage, landfill leachate, food processing discharge, and chemical manufacturing effluents where conventional low- or mid-range kits reach analytical saturation.

Key Features

• Single-step, dry-reagent format: No liquid reagent handling, minimizing operator exposure and preparation error.
• Ultra-rapid reaction kinetics: Complete oxidation and color development within 1 minute after boiling—significantly reducing turnaround time versus standard 2-hour reflux methods.
• Pre-weighed, vacuum-sealed vials ensure batch-to-batch reproducibility and eliminate weighing variability inherent in manual reagent preparation.
• Integrated calibration reference: Each kit includes a stable, traceable color comparator chart covering seven discrete concentration points (0, 10, 100, 500, 1000, 2000, and ≥10,000 mg/L COD).
• Robust thermal design: Vials withstand standard 150°C oil bath or block heater conditions without leakage or degradation during the mandatory digestion step.
• Traceability and documentation: Lot-specific certificate of analysis provided, including certified reference material (CRM) verification data aligned with NIST-traceable standards.

Sample Compatibility & Compliance

The WAK-COD-WR kit is validated for use with clarified, filtered, or centrifuged aqueous samples exhibiting turbidity ≤ 50 NTU and chloride concentrations ≤ 2000 mg/L (with optional mercury-free chloride compensation available via supplemental protocol). It complies with Japanese Industrial Standard JIS K 0102 (2021 edition), International Organization for Standardization ISO 6060:1989 (Water quality — Determination of chemical oxygen demand), and ASTM D1253-22 (Standard Test Method for Chemical Oxygen Demand of Water). While not intended for regulatory submission without laboratory validation, the kit meets internal QC, process monitoring, and pre-screening requirements under ISO/IEC 17025-accredited environmental testing programs. Data generated supports GLP-aligned recordkeeping when paired with Kyoritsu’s optional digital logbook templates.

Software & Data Management

Although the WAK-COD-WR operates as a standalone visual/photometric method, Kyoritsu provides free companion software (Kyoritsu LabLink v3.2) for Windows-based data capture, trend analysis, and report generation. When used with Kyoritsu’s WAK-Reader series photometers (e.g., WAK-Reader 500), the system automatically applies vial-specific calibration curves, stores timestamped results with user ID and sample ID metadata, and exports CSV or PDF reports compliant with FDA 21 CFR Part 11 audit trail requirements—including electronic signatures, version control, and immutable event logging. All calibration files are digitally signed and checksum-verified to prevent unauthorized modification.

Applications

• Wastewater treatment plant influent/effluent monitoring for real-time process control and compliance verification.
• Industrial pretreatment verification in electroplating, textile dyeing, pharmaceutical synthesis, and petrochemical facilities.
• Environmental site assessment of contaminated groundwater and sediment pore water.
• Educational laboratories requiring safe, repeatable COD methodology without reflux apparatus or hazardous waste generation.
• Emergency response teams conducting rapid screening during spill events or combined sewer overflows (CSOs).
• Contract laboratories performing tiered testing—using WAK-COD-WR for initial triage prior to confirmatory SM 5220D analysis.

FAQ

What is the shelf life of unopened WAK-COD-WR vials?

Unopened vials retain full performance for 24 months from manufacture date when stored at 2–25°C in original packaging, protected from light and humidity.
Can this kit be used for seawater or high-salinity samples?

Chloride interference must be addressed: For samples >1000 mg/L Cl⁻, use the optional WAK-Cl Compensation Additive (Cat. No. WAK-CL-ADD) per Kyoritsu Technical Bulletin TB-COD-07.
Is digestion temperature critical—and what happens if boiling time exceeds 1 minute?

Yes. Precise 1-minute digestion at ≥150°C is required for stoichiometric oxidation. Overheating or extended duration may cause over-oxidation of refractory compounds or nitrate reduction, leading to positive bias.
How does WAK-COD-WR compare to HACH DR3900-compatible COD vials?

WAK-COD-WR offers identical measurement principle and range but features tighter lot-to-lot CV (<3.2% vs. typical 4.5%), JIS-certified comparator charts, and direct traceability to Japan’s National Metrology Institute (NMIJ) reference materials.
Are replacement color charts available separately?

Yes. Kyoritsu supplies recalibration chart sets (Cat. No. WAK-COLOR-CHART-WR) certified annually against NMIJ SRM 2002a, with expiration tracking and batch-specific uncertainty statements.