How should bottles be prepared for metal analysis?

For metal analysis, it is essential that sample bottles are prepared in a way that prevents contamination and ensures accurate results. The correct method involves rinsing the bottles with a suitable solution to eliminate any potential contaminants. Rinsing with acid prepares the bottles appropriately for metal analysis by removing any residues that might affect the measurement of metal concentrations in the samples.

When using acid, typically hydrochloric acid (HCl) or nitric acid (HNO3), it helps to remove any trace metals or foreign substances that may interfere with the test results. This process ensures that the bottles are clean and ready to collect samples without introducing additional metal ions from the bottle material itself.

The other methods, while they may have their specific applications, do not provide the necessary level of cleanliness for metal analysis. Distilled water, for instance, may still leave some residues, and autoclaving or baking could alter the material of the bottles or not sufficiently remove contaminants for the highly sensitive analysis of metals. Thus, rinsing with acid is the most effective preparation method for ensuring the integrity of metal analysis samples.