Figure F20. Comparison of perfluorocarbon tracer (PFT) and bead contamination tests in sediments cored by advanced piston coring (APC) or extended core barrel (XCB). The perfluorocarbon (PFC) tracer was recalculated to microliters of seawater potentially introduced into a gram of sediment in proportion to the tracer concentration. The lines indicate limits below which contamination was undetectable.