Why are particulate samples ground before chemical analysis?

In analytical chemistry, particulate samples are ground—a process known as comminution—primarily to reduce the average particle size until the analyte can be considered a pointlike component of the entire laboratory sample. This specific particle diameter is referred to as the liberation size.1

By achieving this state, the sample becomes more homogeneous, which is essential for ensuring that the small test portion selected for analysis is truly representative of the original material. If a sample remains heterogeneous, especially when dealing with trace-level analytes, the resulting data can become erratic or statistically skewed, leading to inaccurate measurements. Grinding helps minimize subsampling errors, allowing for more reliable and reproducible analytical results.12