reduced sample

https://doi.org/10.1351/goldbook.R05217
A representative part of the primary (composited or gross) sample obtained by a division and reduction process. Typically the mass approximates that of the final laboratory sample.
Source:
PAC, 1990, 62, 1193. 'Nomenclature for sampling in analytical chemistry (Recommendations 1990)' on page 1205 (https://doi.org/10.1351/pac199062061193)