In analytical chemistry, sample preparation (processing) refers to the ways in which a sample is treated prior to its analysis. Preparation is a very important step in most analytical techniques, as the techniques often do not react to the analyte in its in situ form, or the results are distorted by interfering species. Sample preparation may involve dissolution, extraction, reaction with some chemical species, comminution, treatment with a chelating agent (eg, EDTA), masking, filtration, dilution, sub-sampling, or many other techniques. Treatment is performed to prepare the sample in a form ready for analysis using specified analytical equipment. Sample preparation may include: crushing and dissolution, chemical digestion with acid or alkali, sample extraction, sample cleanup, and sample preconcentration.
