Hach COD Reagent Kits (Multiple Models)

Overview

Hach COD Reagent Kits are standardized, pre-measured chemical reagents designed for the accurate determination of Chemical Oxygen Demand (COD) in wastewater, surface water, and industrial effluents using the closed-reflux colorimetric method per ASTM D1252–12 (Method 4500-CE) and ISO 6060. These reagents enable rapid, reproducible quantification of oxidizable organic matter by measuring the reduction of dichromate under acidic, high-temperature digestion conditions, followed by spectrophotometric detection at 600 nm or 420 nm depending on the concentration range. Engineered for precision and lot-to-lot consistency, each kit contains vials with precisely dosed potassium dichromate, sulfuric acid, silver sulfate catalyst, and mercury sulfate to suppress chloride interference—ensuring compliance with regulatory digestion protocols required for environmental discharge monitoring and wastewater treatment plant performance assessment.

Key Features

• Two calibrated concentration ranges: Low-range (0–150 mg/L COD) and high-range (0–1500 mg/L COD), supporting broad applicability across municipal and industrial sample matrices
• Pre-filled, sealed digestion vials eliminate manual reagent handling—reducing analyst exposure, minimizing pipetting error, and improving inter-laboratory reproducibility
• Mercury sulfate included to complex chloride ions up to 2000 mg/L Cl⁻, enabling reliable COD measurement in saline or brackish samples without dilution
• Compatible with all major Hach benchtop and portable spectrophotometers including DR5000, DR2800, DR850, and DR890—leveraging built-in COD methods and calibration curves
• Manufactured in the USA under strict ISO 9001-certified quality systems; each lot undergoes rigorous QC verification against NIST-traceable standards
• Stable shelf life of ≥24 months when stored at 15–25°C; no refrigeration required

Sample Compatibility & Compliance

These reagent kits are validated for use with raw sewage, secondary effluent, landfill leachate, food processing wastewater, and pulp/paper mill discharges. They meet the analytical requirements of U.S. EPA Method 410.4 and support compliance reporting under Clean Water Act (CWA) NPDES permits. The digestion protocol aligns with ISO 6060:1989 and ASTM D1252–12 (both Parts A and B), and results are suitable for GLP/GMP environments where audit-ready documentation is required. When used with Hach instruments configured for 21 CFR Part 11-compliant software (e.g., Hach LabStation with electronic signature and audit trail enabled), full data integrity and regulatory traceability are maintained.

Software & Data Management

Each kit integrates seamlessly with Hach’s instrument firmware and associated software platforms. Preloaded COD methods in DR series spectrophotometers auto-select wavelength, blank correction, and calibration curve based on vial barcode scan or manual selection (e.g., “COD Low Range” or “COD High Range”). Raw absorbance data, digestion time stamps, operator IDs, and calibration history are logged directly into instrument memory and exportable via USB or Ethernet to LIMS or Excel. For laboratories operating under regulated workflows, optional Hach LabStation software provides electronic signatures, user access controls, and immutable audit trails compliant with FDA 21 CFR Part 11 and EU Annex 11 requirements.

Applications

• Wastewater treatment plant process control and effluent compliance monitoring
• Industrial pretreatment program verification (e.g., textile, pharmaceutical, chemical manufacturing)
• Environmental laboratory accreditation (ISO/IEC 17025) for routine COD testing
• Research studies evaluating biodegradability, oxidation kinetics, and inhibitor effects
• Educational labs requiring safe, standardized, and repeatable COD experiments

FAQ

What is the shelf life of Hach COD reagent kits?
Unopened vials retain full performance for 24 months from manufacture date when stored between 15°C and 25°C in dry, dark conditions.
Can these reagents be used with non-Hach spectrophotometers?
Yes—provided the instrument supports absorbance measurement at 600 nm (low range) or 420 nm (high range) and allows user-defined calibration curves; however, method validation per local regulatory requirements is the user’s responsibility.
Do I need to perform a blank correction for every batch?
Yes—each digestion run requires a reagent blank (vial containing only reagents, no sample) to account for background absorbance; Hach instruments automate this step when the “Blank” function is initiated prior to sample measurement.
How does chloride interference affect COD results—and how is it mitigated?
Chloride ions reduce dichromate independently, causing positive bias; mercury sulfate in the reagent binds Cl⁻ stoichiometrically, suppressing interference up to 2000 mg/L—exceeding typical municipal wastewater chloride levels.
Are safety data sheets (SDS) available for these kits?
Yes—GHS-compliant SDS documents are accessible via Hach’s official portal (hach.com/sds) using the product catalog number (e.g., 21258-25); they include handling, disposal, and first-aid guidance per OSHA and CLP regulations.