Water that is to be analyzed for inorganic metals should be codified with which substance?

The appropriate choice for the analysis of water for inorganic metals is concentrated nitric acid. This substance is widely used in analytical chemistry as a digestion agent because it effectively dissolves a variety of metal compounds. It has the ability to oxidize metals, breaking down complex and stable forms into ionic species that can be easily measured and analyzed using methods like atomic absorption spectroscopy or inductively coupled plasma mass spectrometry.

Concentrated nitric acid provides a strong acidic environment that ensures the complete dissolution of metals, and it also prevents the precipitation of metals, which could interfere with the analytical results. Additionally, its volatility allows for easy removal of excess acid after digestion, leaving a solution that is conducive to accurate analysis.

In contrast, other acids such as hydrochloric acid, sulfuric acid, and acetic acid do not possess the same capabilities for digesting inorganic metals in an effective and reliable manner for this type of analysis. While they may be useful in certain contexts, they are not the standard choice for preparing samples specifically for the determination of inorganic metal content in water samples.