Why is it important to dry a sample before analysis?

Drying a sample before analysis is critical primarily because it eliminates water, which can significantly interfere with measurements. Water can alter the concentration of analytes, lead to variations in physical properties such as density, viscosity, and refractive index, and can affect the outcomes of various analytical techniques. For instance, in gravimetric analysis, the presence of water can lead to the formation of hydrates, which would change the mass of the sample and thus skew results. In spectroscopic methods, water can absorb light in certain wavelengths, leading to inaccurate readings.

Removing water ensures that the sample is in its intended state for precise and reproducible results, allowing for a clearer interpretation of the data obtained during the analytical process. This understanding is vital for achieving accurate quantification and ensuring that the chemical composition of the sample is not misrepresented during analysis.