Chemical Stability and Compatibility - Heavy metal impurity testing in HNO3
Is it possible to prepare a mixture of these elements (Ni, As, Pb, Hg, Co, Cd) in one solution using 2% HNO3?
Would there be any problems using ICP-MS with the same matrix?
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admin
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The elements you list (Ni, As, Pb, Hg, Co, Cd) can be mixed together and are chemically stable in a 2% (v/v) HNO3 matrix with the following exception: Hg at concentrations typically used for ICP-MS analyses (<1 ppm) can suffer instability if the container used to store the solution is plastic (please see https://www.inorganicventures.com/mercury-chemical-stability for more information). As a result, for low concentrations of Hg in a 2% (v/v) HNO3 matrix it may be more appropriate to create and store the mixture in glass labware, though please be aware that any plastic that forms part of the ICP-MS sample introduction system (pump tubing, etc.) can also adsorb Hg and potentially create washout/memory effects. |