batch

in analytical chemistry
https://doi.org/10.1351/goldbook.B00613
A quantity of material which is known or assumed to be produced under uniform conditions. Some vocabularies assume 'lot' and 'batch' to be synonymous. The distinction made here with respect to knowledge of production history permits a lot to consist of one or more batches and is useful in interpreting the results of analysis.
Source:
PAC, 1990, 62, 1193. 'Nomenclature for sampling in analytical chemistry (Recommendations 1990)' on page 1202 (https://doi.org/10.1351/pac199062061193)