Utilizing 250 mL sample volumes for EPA method 1664B extractions

EPA Method 1664B was developed for measuring oil and grease in wastewater with Hexane Extractable Material (HEM) concentrations ranging from 5 to 1000 mg/L. However, samples containing high oil and grease content (> 500 mg/L HEM) are challenging to extract and therefore the method allows for a smaller sample to be collected. To run reduced sample volumes, laboratories must be able to demonstrate the ability to meet the method detection limit (MDL) requirements at the reduced sample volume level. This application note provides a full solution for EPA method 1664B that meets the method detection limits at 250 mL sample volumes.