matrix effect

matrix effect

(1) The difference between the value of an analyte from a fresh patient specimen and from stabilised processed reference materials.
(2) The influence of a sample property—other than the level of the substance or property being measured in the analyte—on a measurement, and thus on the value of the measurand. Matrix effects include physicochemical, mechanistic and analytical interferences, and the presence of isoforms of the substance being measured.