Interferent

An interferent is any substance, organism, or signal that causes interference in a measurement, reaction, or signal detection, thereby reducing accuracy or reliability. The term is used across scientific and engineering disciplines to describe factors that distort results or degrade performance.

In analytical chemistry and laboratory assays, interferents can react with reagents, absorb or scatter light at the measurement wavelength, or alter the sample matrix. This can bias results in clinical chemistry, environmental testing, and instrumental analyses. Common examples include bilirubin, lipids, and hemoglobin that cause spectral or colorimetric interference; matrix components that suppress or enhance signals in chromatography or mass spectrometry; and substances that cross-react in immunoassays.

In immunoassays and toxicology, endogenous substances such as heterophile antibodies or rheumatoid factors can bind assay components and generate false positives or negatives. In environmental and food testing, interferents may include salts, humic substances, or varying ionic strength that distort quantification.

In electronics, communications, and signal processing, an interferent refers to a competing signal or external source that causes electromagnetic interference or crosstalk, degrading signal integrity. Mitigation strategies include shielding, filtering, proper calibration, sample pretreatment, dilution, and validation studies to assess and account for potential interference.

The concept, rooted in the idea of interference, emphasizes the need to identify, understand, and control undesired influences to ensure accurate measurement, reliable detection, and robust system performance.