Chemical oxygen demand (COD) measurement context
EPA Method 410.4. The sample is heated with dichromate in a sealed tube at 150 °C for two hours and the result is read by spectrophotometry. Soluble COD is measured on a filtered portion and ff-COD on a flocculated and filtered portion; tell us which you need and we agree the preparation with you. Reported as mg/L oxygen equivalent.
Connect the parameter to the sample plan
Specify grab or composite collection where applicable, the reporting unit and any field or preparation requirements. Keep nitrogen, phosphorus, solids and demand measurements on their correct reporting basis.
Include the complete project requirement
Provide the matrix, target analytes, required method, fraction, units and reporting limits. Include the permit or monitoring instructions where results will support a regulatory submission. Naming this method does not establish blanket compliance eligibility.
Resolve collection before sampling
Use the bottle, preservation and delivery instructions assigned to the agreed scope. Identify each location and collection time, and document any deviation. The final analytical plan must fit the submitted material and its intended use.
Related testing & guidance
Technical & service references
Vanguard service detailsSource review: November 8, 2026. The agreed method and project scope govern the testing.