Lianhua Technology LH-COD-K21 On-Site COD Quick Test Kit
| Brand | Lianhua Technology |
|---|---|
| Origin | Beijing, China |
| Manufacturer Type | Direct Manufacturer |
| Country of Origin | China |
| Model | LH-COD-K21 |
| Pricing | Available Upon Request |
Overview
The Lianhua Technology LH-COD-K21 On-Site COD Quick Test Kit is a field-deployable colorimetric assay system engineered for rapid, semi-quantitative determination of Chemical Oxygen Demand (COD) in aqueous samples. It operates on the principle of dichromate digestion under acidic conditions, followed by spectrophotometric measurement of the reduced Cr(III) ion at 600 nm — a method aligned with the core analytical framework of ISO 6060 and APHA Standard Methods 5220 B. Unlike laboratory-based COD analyzers requiring reflux apparatus and 2-hour digestion, the LH-COD-K21 integrates pre-measured reagents into sealed glass vials, enabling complete sample processing in under 15 minutes with minimal equipment: a portable digital colorimeter (optional), timer, and calibrated pipette. Designed for operational resilience in non-laboratory environments, it delivers consistent performance across variable ambient temperatures (10–35 °C) and humidity levels typical of field deployments.
Key Features
- Pre-calibrated, single-use glass test vials containing precise quantities of potassium dichromate, sulfuric acid, and silver sulfate catalyst — eliminating manual reagent preparation and reducing operator error.
- Integrated digestion and color development in one vial: no transfer steps, no risk of cross-contamination or sample loss.
- Optimized for visual comparison using included standard color chart (0–150 mg/L COD range) or quantitative analysis via compatible handheld photometers (e.g., Lianhua LH-3B series or third-party devices with 600 nm filter).
- Ruggedized packaging with moisture-resistant foil pouches and impact-absorbing foam inserts — validated for transport in vehicle-mounted cabinets and backpack-style field kits.
- No external power source required; fully functional without electricity, making it suitable for remote locations, emergency response vehicles, and mobile environmental inspection units.
- Batch-certified reagent stability: 18-month shelf life when stored at 4–25 °C; lot-specific calibration certificates traceable to NIM (National Institute of Metrology, China) reference standards.
Sample Compatibility & Compliance
The LH-COD-K21 kit is validated for use with raw and treated wastewater, aquaculture effluent, agricultural runoff, ornamental pond water, and municipal sewage influent/effluent. It accommodates turbid and mildly colored samples without filtration, provided suspended solids do not exceed 100 mg/L — a limitation consistent with EPA Method 410.4 guidance for field COD screening. While not intended for regulatory reporting under US EPA or EU Water Framework Directive compliance programs, the kit meets Chinese HJ/T 399-2007 technical requirements for rapid COD testing and supports internal quality control, process monitoring, and preliminary screening prior to confirmatory lab analysis. All reagents comply with GB/T 6682-2008 specifications for analytical grade water and chemical purity.
Software & Data Management
As a reagent-based rapid test system, the LH-COD-K21 does not incorporate embedded firmware or proprietary software. However, it is fully compatible with Lianhua’s LH-DataLink mobile application (iOS/Android) for digital logging: users may scan vial barcodes, record sampling location (GPS-tagged), enter operator ID, and capture photo-based color comparisons. Exported CSV files include timestamp, sample ID, measured absorbance (if photometer used), and calculated COD value — supporting audit-ready documentation for GLP-aligned environmental monitoring programs. All data exports are timestamped and immutable post-upload, satisfying basic 21 CFR Part 11 principles for electronic records where local regulatory interpretation permits.
Applications
- Emergency response teams assessing industrial discharge incidents or stormwater overflow events.
- Aquaculture facility managers performing daily pond water quality checks to prevent hypoxia-induced mortality.
- Municipal wastewater operators conducting real-time evaluation of treatment plant influent strength during peak flow periods.
- Agricultural extension services monitoring nutrient loading from irrigation return flows and livestock runoff.
- Educational institutions utilizing the kit for undergraduate environmental chemistry labs focusing on redox titration fundamentals and field methodology.
- Mobile environmental inspection units conducting unannounced site audits under provincial ecological supervision frameworks.
FAQ
What is the detection range of the LH-COD-K21 kit?
The standard configuration covers 0–150 mg/L COD. Extended-range versions (0–1000 mg/L) are available upon request and require dilution protocol adherence per included instructions.
Can this kit be used for seawater or brackish water samples?
Chloride interference is mitigated up to 2000 mg/L Cl⁻ by the inclusion of mercury-free chloride compensation chemistry; however, validation is recommended for matrices exceeding 1500 mg/L salinity.
Is operator training required?
Yes — Lianhua provides certified 2-hour field competency training covering safe handling of acidic reagents, colorimetric interpretation, and chain-of-custody documentation for regulatory traceability.
How are results verified for accuracy?
Each production batch undergoes parallel analysis against certified reference materials (CRMs) from NIM; certificate of analysis (CoA) is supplied with every kit shipment.
Does the kit meet ISO/IEC 17025 requirements?
While the kit itself is not accredited, its use within an ISO/IEC 17025-accredited laboratory — following documented SOPs and participation in interlaboratory comparison studies — supports method validation under Clause 7.2.2.
