EPA Method 8270D is used to determine a list of up to 243 semi-volatile organic compounds that are neutral, acidic, basic, and are soluble in methylene chloride. Semi-volatile water samples can contain varying amounts of suspended particulates and/or sediment due to either the source of the water, or the collection technique. By elevating the pH of semi-volatile samples, precipitates can form and result in an emulsion that can create problems for an efficient extraction with traditional techniques. These types of samples, due to their sediment content, have historically proven very challenging when using solid phase extraction (SPE).