Not a reference, But we use a brand that does not have those stainless steel pipette tip ejectors.
Also, there is a bottle top dispenser that advertises inert sample path, but it has a platinum ball in the valve mechanism. If you stop using this dispenser for 30 minutes, in maybe the third or fourth sample, chromium and nickel (trace components of the platinum ball) sharply increase, then trail off as the leached Cr and Ni are rinsed out. The message is, avoid components in contact with, or even near acids that have a steel surface, and be aware that even 0.01% impurities from 99.99% pure Pt are sufficient to throw a monkey wrench into the works of ICP-MS sample prep.
R. Steven Pappas, Ph.D.
Team Lead, Tobacco Inorganics Group
Centers for Disease Control & Prevention
4770 Buford Highway, NE
M.S. F44, Building 110
Atlanta, GA 30341-3717, USA
From: PLASMACHEM-L: Analytical Chem.(ICP's, DCP's, MIP's). <[log in to unmask]> On Behalf Of Taylor, Robert J
Sent: Thursday, May 10, 2018 2:34 PM
To: [log in to unmask]
Subject: anomalously high Ni and Cr = contamination from stainless steel?
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