Overview

Consider the stability of acidic solutions of the elements. When looking at routes of instability, the trace analyst typically thinks of stability in connection with the concentration of the element. For example, when considering the stability of solutions at the part-per-million (ppm) concentration level, instability is generally caused by precipitation formation or photo-reduction reactions. However, the main route of instability at the part-per-billion (ppb) level is derived from adsorption to the container walls.

The stability of elemental solutions at the ppm level is more an issue of compatibility and is addressed in detail in our Interactive Periodic Table. Plus, the stability of acidic elemental solutions is typically easy to achieve. It's difficult to imagine any route of instability for most elements. Take copper, for instance. Cu at the ppm concentration level in nitric acid is stable indefinitely. However, that same solution diluted down into the low to mid ppb concentration level makes the possibility of instability (caused by adsorption) a very real concern.