In the course of analyzing many tissue samples, we have interpreted observation of anomalously high nickel and chromium as having originated from stainless steel. One of the NIST SRMs had this issue, if memory serves, because stainless steel implements were used at some point for sample processing. Similarly, we've inferred anomalously high values for both Ni and Cr as indicators of particulate contamination resulting from corrosion of stainless steel surfaces (HCl is not a friend to stainless steel).
Might anyone be aware of a reference to this observation?
Robert J. Taylor
Trace Element Research Laboratory
Department of Veterinary Integrative Biosciences
College of Veterinary Medicine
Texas A&M University
College Station, TX 77843-4458