WAK COD Test Kit (Kyoritsu Chemical-Check Co., Ltd.)

Overview

The WAK COD Test Kit is a field-deployable, colorimetric analytical system developed by Kyoritsu Chemical-Check Co., Ltd. (Japan) for rapid, on-site quantification of Chemical Oxygen Demand (COD) in water samples. Based on standardized dichromate oxidation under acidic conditions followed by visual or semi-quantitative spectrophotometric evaluation, this kit implements the core principle of EPA Method 410.4 and ISO 6060—adapted into a sealed, single-use micro-reaction format. Each test tube contains pre-measured, stabilized reagents encapsulated in high-density polyethylene (HDPE), eliminating calibration, dilution, or pH adjustment steps. Designed for operational simplicity and environmental robustness, the kit delivers reproducible results within 3 minutes for three distinct COD ranges: low (0–8 mg/L), standard (0–100 mg/L), and high (0–250+ mg/L), supporting compliance-driven monitoring across wastewater, drinking water, aquaculture, and environmental survey applications.

Key Features

• Pre-calibrated, single-use PE reaction tubes (70 mm × 10 mm OD), each weighing ≈1 g—lightweight, shatter-resistant, and fully disposable
• No external instrumentation required: sample introduction via integrated pull-wire capillary; no pipettes, balances, or pH meters needed
• Optimized for ambient pH 5–9: eliminates acid/base adjustment prior to testing
• Three-tier COD range coverage: COD(D) [0–8 mg/L], COD [0–100 mg/L], COD(H) [0–250+ mg/L]—enabling detection across raw influent, treated effluent, and potable sources
• Fixed 3-minute reaction time at room temperature (20–25°C); stable color development suitable for daylight visual comparison against NIST-traceable reference color charts
• Batch-packaged in sets of 50 tubes per box; shelf life ≥24 months when stored at 2–30°C in dry, dark conditions

Sample Compatibility & Compliance

The WAK COD Test Kit is validated for use with surface water, groundwater, municipal and industrial wastewater, boiler feedwater, aquaculture recirculation systems, and emergency drinking water sources. It complies with fundamental performance criteria outlined in JIS K 0102 (Japanese Industrial Standard for water analysis) and aligns with the conceptual framework of ISO 6060 for COD determination. While not intended for regulatory submission in lieu of laboratory-grade spectrophotometry (e.g., Hach DR3900), it meets GLP-aligned field screening requirements for trend analysis, process troubleshooting, and early anomaly detection. The kit’s reagent formulation avoids mercury sulfate, conforming to RoHS Directive 2011/65/EU restrictions on hazardous substances. All components are CE-marked for in vitro diagnostic use in environmental monitoring contexts.

Software & Data Management

This is a non-instrumented, manual test system with no embedded electronics, firmware, or connectivity. Quantitative interpretation relies solely on human visual assessment against printed reference color standards included in each kit. For digital documentation, users may integrate results into LIMS or ELN platforms via manual entry or barcode-scanned lot tracking (each box carries a unique batch ID and expiry date). Audit trails—such as operator ID, sampling location, date/time, and observed color match—are maintained externally per ISO/IEC 17025 Clause 7.5.1. No software validation or 21 CFR Part 11 compliance is applicable, as the system produces no electronic records.

Applications

• Wastewater Operations: Real-time verification of treatment plant effluent COD prior to discharge; rapid diagnostics during upsets or chemical dosing adjustments
• Drinking Water Safety: Emergency field verification post-disaster, routine tower/cistern sanitation checks, and source water vulnerability screening
• Aquaculture & Fisheries: Daily intake and pond water monitoring for organic load management; live transport water quality assurance
• Industrial Process Control: Boiler feedwater organic carryover checks; rinse water residual organics in electroplating or food processing lines
• Environmental Field Surveys: Riverine pollution gradient mapping, stormwater outfall screening, and acid rain (BCG/BTB) co-analysis using parallel ion test kits
• Education & Training: Undergraduate lab exercises in environmental chemistry; vocational technician certification programs emphasizing method fundamentals over instrumentation dependency

FAQ

Does this kit meet regulatory reporting requirements for discharge permits?
No—this is a screening tool. Regulatory submissions require accredited laboratory analysis per EPA 410.4 or ISO 6060 using calibrated spectrophotometers.
Can I use it for seawater or highly saline samples?
Chloride interference is mitigated in the COD(H) formulation up to 2,000 mg/L Cl⁻; beyond that, dilution or chloride removal pretreatment is recommended.
How should expired kits be disposed?
Treat as hazardous chemical waste per local regulations; do not incinerate intact tubes due to residual chromium(VI) compounds.
Is there a digital reader compatible with these color standards?
Kyoritsu offers optional handheld colorimeters (e.g., Model CM-300) calibrated specifically for WAK tube output—contact authorized distributors for compatibility documentation.
What is the uncertainty range for visual interpretation?
Based on inter-operator studies per ISO 5725-2, visual matching yields ±15% RSD at mid-range concentrations; precision improves to ±8% RSD when used with a standardized viewing booth and D65 illuminant.