In partial digestion and/or selective digestion procedures only part or some of the analytes present are brought into solution. This may be preferred to total decomposition if relative concentrations of the analyte in the test samples provide sufficient information (e.g. materials for geochemical exploration).
Source:
PAC, 1988, 60, 1461. 'Nomenclature, symbols, units and their usage in spectrochemical analysis-X. Preparation of materials for analytical atomic spectroscopy and other related techniques (Recommendations 1988)' on page 1469 (https://doi.org/10.1351/pac198860091461)