Hach COD Pre-Mixed Reagent Vials for Water Quality Analysis

Overview

Hach COD Pre-Mixed Reagent Vials are factory-sealed, colorimetric test kits engineered for rapid, accurate, and reproducible chemical oxygen demand (COD) determination in wastewater, surface water, drinking water, and industrial effluents. Based on the standardized dichromate oxidation method (ASTM D1252–04, ISO 6060), these reagents eliminate manual preparation errors by delivering precise concentrations of potassium dichromate, sulfuric acid, silver sulfate catalyst, and mercury sulfate (for chloride interference suppression) in a single-use, ready-to-use glass vial. Each vial is calibrated and validated against NIST-traceable standards, ensuring compliance with EPA Method 410.4 and supporting routine monitoring under regulatory frameworks including Clean Water Act (CWA) discharge reporting and ISO 17025-accredited laboratory workflows.

Key Features

• Pre-weighed, pre-mixed reagents sealed under inert atmosphere to ensure shelf-life stability (up to 2 years unopened at room temperature)
• No user handling of hazardous chemicals—eliminates exposure risk and reduces PPE requirements
• Optimized for Hach spectrophotometers (DR6000, DR3900, DR1900, DR900, DR1010) with built-in COD methods and calibration curves
• Four distinct range options enable method selection based on sample matrix: low-range (0.7–40 mg/L), standard-range (3–150 mg/L), high-range (20–1500 mg/L), and ultra-high-range (200–15000 mg/L)
• Chloride tolerance up to 2000 mg/L (with mercury sulfate included in applicable vials), minimizing need for dilution or pretreatment
• Batch-specific certificate of analysis provided with each kit, including lot number, expiration date, and verification against certified reference materials

Sample Compatibility & Compliance

The reagent series supports aqueous samples with minimal suspended solids and turbidity (2000 mg/L), strong oxidants (e.g., residual chlorine >2 mg/L), or reducing agents (e.g., sulfides, ferrous iron) require appropriate pretreatment per Hach Method 8000 guidelines. All vials comply with CLP/GHS labeling requirements and meet UN transport classification criteria for Class 8 corrosive substances. The manufacturing process adheres to ISO 9001 quality management systems, and reagent performance is verified per ISO/IEC 17025:2017 clause 5.4.2 for measurement traceability. Kits are suitable for use in GLP- and GMP-regulated environments where audit-ready documentation—including electronic batch records and instrument method logs—is required.

Software & Data Management

When used with Hach’s AquaTrack™ software or the embedded firmware of DR-series spectrophotometers, the reagents integrate seamlessly into structured data workflows. Instrument methods auto-load corresponding calibration curves upon vial barcode scan (where supported), and results are timestamped, user-ID tagged, and stored with full audit trail per FDA 21 CFR Part 11 requirements. Export formats include CSV, PDF report, and direct LIMS integration via Hach’s Enterprise Data Exchange (EDX) protocol. All calibration data, drift checks, and QC sample results are retained within the instrument memory for ≥12 months, supporting internal QA reviews and external accreditation audits.

Applications

• Wastewater treatment plant influent/effluent monitoring per NPDES permit conditions
• Industrial pretreatment program compliance (e.g., food processing, pharmaceutical, textile sectors)
• Environmental lab accreditation testing under ISO/IEC 17025 scope
• Process control in activated sludge, MBR, and tertiary treatment systems
• Educational laboratories requiring standardized, safe, and repeatable COD experiments
• Field-deployable testing when paired with portable DR1010 or DR900 instruments

FAQ

Are these reagents compatible with non-Hach spectrophotometers?
Yes, but only if the instrument supports user-defined wavelength settings (600 nm or 620 nm) and absorbance-based quantification; however, Hach-specific calibration curves and method automation are not available outside the DR-series platform.

What is the shelf life after opening a vial pack?
Once opened, vials must be used within 30 days and stored at 10–30 °C in original packaging, protected from light and moisture.

Do I need to perform blank corrections manually?
No—the DR-series instruments execute automatic zeroing using a reagent blank (deionized water in identical vial) prior to sample measurement, as defined in the onboard method protocol.

Can these reagents be used for marine or brackish water samples?
They are validated for freshwater and secondary-treated wastewater; for high-salinity matrices (>10,000 µS/cm), chloride interference may persist beyond the specified tolerance—dilution or alternative methods (e.g., closed-reflux titrimetric) are recommended.

Is mercury-free COD testing available in this series?
No—these vials contain mercury sulfate to suppress chloride interference. For mercury-free alternatives, consult Hach’s COD Ultra Low Range (ULR) kits, which employ proprietary catalyst formulations compliant with ASTM D1252B.