What are typical Background values for the extractors?
First, let’s discuss the background values typically found with method 1664A. A clean extractor system with clean solvents (and no disk), should give a background value of 0.5 – 0.75 mg. Based on the particular disk used, and the size of the disk (47 or 90 mm), the background value could range from 0.75 – 1.5 mg. Most of the higher backgrounds are a result of the SPE disk. Various steps can be taken to reduce these higher values.
