blank material 

Synonym: blank
https://doi.org/10.1351/goldbook.08010
Material which contains no, or as little as possible, of the analyte of interest used in measurement to establish a blank indication.
Notes:
  1. Testing, processing, and measurement of blank materials are nearly always an essential part of chemical analysis and may be part of quality assurance and quality control.
  2. The concept may be extended to more than one analyte.
  3. Terms such as "solvent blank", "reagent blank", or "matrix blank" are often used to specify the type of blank material.
  4. The term "procedure (or procedural) blank" is often used to denote a material that is carried through the entire measurement procedure. Terms such as "field blank", "calibration blank", and "instrument blank" refer to materials handled in specific parts of the measurement procedure.
  5. A blank material to which a relevant component has been added is often termed "spiked blank" or "fortified blank". Compare spike, internal standard, and measurement procedure with standard addition.
  6. If the term "blank" is used, for example, to denote blank indication or the related blank value or blank correction, this must be clarified by the context.
Source:
PAC, 2021, 93, 997. 'Metrological and quality concepts in analytical chemistry (IUPAC Recommendations 2021)' on page 1001 (https://doi.org/10.1515/pac-2019-0819)